Complex Matters

The Dark and Evil Forest (My Backyard)

2010-10-09T07:30:00.000-07:00

The house (or “terraced” as they call it here) that I rent from the college has a nice little garden in the back. As I mentioned shortly after moving in, I did not have much motivation to take good care of the garden. Then later that year, when I discovered a giant monster spider named Shelob living there, I decided that it was a good idea never to set foot in the garden again.

A year later, as one might expect, the garden began to get a bit overgrown. Actually, it began to get a lot overgrown. It looked like the deepest and darkest part of the Amazon jungle: I keep expecting to see anacondas and jaguars.

Unfortunately, it is written in my lease that I am supposed to keep the garden under control, and the all-knowing powers-that-be at college found out what it looked like and sent me an email reminder

This is just a gentle reminder that we do expect the tenants of College houses to keep the garden of their house under control

(This was actually one of the 363 emails that were lost this summer, so I managed to spend the whole summer thinking I had gotten away with my jungle experiment.)

This is what my garden looked like yesterday:
My excuse – that I’m turning the garden into a forest to combat global warming – might not go very far. So early this morning, I went and got myself some garden shears and a bunch of large garden-waste bags and went to work. My first shock was that most of the huge plants that you see in the picture are actually stinging nettles. Although you can apparently make good food from this stuff, the plants are plenty nasty. Even with thick gloves on they can sting you, and it really hurts! You can get some major welts that last for days. So the weed cutting went very slow as I only very gently approached these evil beasts.

Bit by bit, I filled up waste-bag after waste-bag. No doubt this is going to be a long project. So far, this morning, I pulled weeds for about three hours before I ran into Shelob, the monster spider, who scared me back inside. I decided that I’m not going to do any more gardening until later in the fall when it becomes too cold for spiders.

This is where I left the situation.

I know it doesn’t look all that much better, but maybe it is a start. It is hard to even see that it has improved, but believe it or not, there were four full-sized garbage bags of weeds removed from the yard between the first and second photo. At least there are one or two places where you can actually see the ground in the second photo.

The email black hole

2010-10-09T06:30:00.001-07:00

The whole world is far too dependent on email. I am no exception. I have three email accounts that I check many times daily --- and usually I respond fairly quickly, even to things that I could probably ignore with few ill effects. But email is my main connection to most of the world, so I try to keep the lines of communication flowing properly.

This summer, however, something unimaginable happened – my email broke down. (shudder!) I didn’t notice it at first because only a small fraction of my emails were getting lost --- being mistakenly forwarded to a black hole of the cyber-aether. As the term began this fall, increasingly people would say to me “didn’t you get my email?”, and I’d just look puzzled. Finally, this week I figured out that there really was a problem and I started investigating. To my complete horror, I discovered a hidden backlog of 363 emails sent over the last few months. So (after fixing the forwarding problem) I started going through all 363 emails. Perhaps not surprisingly, it turned out that of these 363 emails that I was so horrified to have missed, only 6 turned out to be important enough to actually require a response (and/or an apology for not having responded sooner), and actually even these were not all that crucial. 6 out of 363 --- a pretty small fraction. Considering how much time I spend reading and writing email, I’m starting to wonder if I might not be better off just to send them all down the black hole.

Graphene

2010-10-05T13:03:00.000-07:00

The Nobel Prize in Physics today was awarded for the discovery of Graphene, a single layer carbon sheet. Back in this post in 2009, I mentioned that this was a hot topic at the APS march meeting.

It turns out that the whole trick to producing graphene is Scotch-Tape. If you take a piece of tape and you lightly touch it to graphite (pencil lead) you frequently will pull off just a single layer of carbon. Pretty cool. (This trick for pulling off thin layers with tape has been known for many years to chemists and material scientists).

Back in this post when I was taking bets for last year's Nobel prize, I made the following statement suggesting that it was not actually deserving of the prize:

Reuters proposes Geim and Novoselov (22%) for the discovery of graphene (carbon sheets) and Ijima (14%) narrowly behind for the discovery of nanotubes (carbon sheets rolled up into a tube). Not that I am opposed to carbon but…

I will remind everyone that Buckyballs, yet another form of Carbon, already won the Nobel prize recently – but in chemistry, not physics. I will also remind everyone that not every molecule made of carbon deserves an immediate Nobel prize. I know that the Carbonists have been lobbying hard, and admittedly both nanotubes and graphene are pretty cool. But I don’t think they are so overwhelmingly cool that they need a Nobel prize just yet. And if the lessons of Buckyballs are anything to learn from, we should expect that the hype will far outweigh the actual usefulness of, or interest in, the stuff in the long run.

I'm amused to see that Doug, over at nanoscale views seems to have a similar opinion.

On the flip-side, graphene is pretty cool stuff. If any fraction of the hype turns out to be true in 10 years, then I would certainly support the prize (and simultaneously eat my words). But from the buckeyball experience I would have thought the Nobel committee might have waited a bit longer on this one. It isn't like the winners are old geezers about to croak who have to be given the prize now since they are not going to survive until next year.

So there you have it... the Nobel prize won with Scotch-tape.

Presentation to the Visitor

2010-09-26T09:09:00.000-07:00

Last Saturday, Somerville College officially inaugurated its new Principal, Dr. Alice Prochaska. The ceremony is actually known as “Presentation to the Visitor” with “Visitor” here not meaning something out of star trek, but rather meaning the Chancellor of the University – the Lord Patten of Barnes.

[The person with the real power at the top of the administration is actually the Vice-Chancellor. The Chancellor is mainly a figure head, but does preside at formal occasions such as this one.]

During the ceremony of “Presentation,” the Fellows of the College gather, in academic gowns, in the Senior Common Room. Many were dressed in Black and Red, the Somerville colors. (I was happy just to have found a clean shirt and did not think much about the color). Then the senior fellow of the College, Mrs Lesley Brown, presents the principal-elect to the visitor.

[Mrs Lesley Brown has been a distinguished scholar of Ancient Philosophy at Oxford for many many years – having been elected fellow at Somerville College in 1970, and even having chaired the Philosophy department for several years since then. However, having been elected fellow so young, she actually never bothered to obtain her DPhil or PhD, and is thus listed as Mrs rather than Dr or Professor]

Mrs Brown then did the “presentation”, reading the officially prescribed text, in English (Of all the times when Latin might have been appropriate, this might have been one – being that Mrs Brown is a Latin expert).

I, Mrs Lesley Brown, Fellow of Somerville College, in the University of Oxford hereby declare the Dr Alice Prochaska was formally elected Principal of said College, in Succession to Dame Fiona Caldicott at the stated meeting of the Governing Body held on the 17th June 2009.

Then the Principal Elect makes her declaration:

I, Alice Prochaska, hereby declare that I will faithfully perform the duties of my office as Principal of Somerville College, and will observe the Statutes and By-laws of the College in force for the time being

People were a little puzzled by the phrase “for the time being” that occurs in this declaration, but that is what is officially prescribed in our statutes (although no one could quite explain why this phrase is inserted).

And finally the Visitor confirms that this has been witnessed

I, the Right Honourable Lord Patten of Barnes, Chancellor of the University of Oxford, and Visitor of Somerville College in the University of Oxford, hereby declare that Mrs Lesley Brown, Fellow of Somerville College, having announced to me on this twenty-fifth day of September 2010 that Dr Alice Prochaska had been duly elected Principal of Somerville College, presented to me Dr. Prochaska as said Principal. The said Dr Prochaska declared before me that she would faithfully perform the duties of the office of Principal of Somerville College and would observe the Statutes and By-laws of the College in force for the time being.

That first sentence is a bit hard to Parse, huh?

After the ceremony, toasts were made to Somerville and to our new Principal, and we all adjourned to the Margaret Thatcher Centre (the Iron Lady was a Somervillian) for lunch. This gave the fellows a chance to catch up with each other after their respective summers away.

At one point (after only about four champagnes) I found myself sitting next to the Visitor, the Lord Patten. I should have done my research about him in advance so that I could have intelligently argued with his disparaging remarks about the Black-Scholes equation -- although if his remarks were focused entirely on the excesses of the system and rather than on the wisdom of the Nobel prize, we might have agreed entirely.

Incidentally, you can also read the new principal's view on this event on her blog.

Nobel Bets 2010

2010-09-25T01:06:00.000-07:00

It is that time of year again -- the time when the best and the brightest from around the world lose sleep wondering if they are going to get that early morning call from Sweden announcing that they have won the Nobel prize.

Last year I placed my wager on Yakir Aharonov and Michael Berry for geometric phases in physics. This turned out to be a bad bet. From now on I am removing Aharonov from my list of likely candidates. Why? Because I was informed that the 1961 work he is most famous for actually discovered 12 years earlier by Ehrenberg and Siday (Even Wikipedia appears aware of this). The fact that it is called the “Ahanronov-Bohm effect” appears to be a good example of Stigler’s law: The principle that nothing is ever named after its original discoverer. (Stigler’s law itself was discovered by Merton).

Since last year, the prize went to Smith and Boyle and Kao for what many people disparaged as “just engineering” (albeit some pretty amazing engineering). Given that, I think this year the prize might go to something a bit more fundamental. A decent bet would be Sir Michael Berry (without Aharonov).

However, for my money, I think the front-runner is the WMAP experiment (Wilkenson Microwave Anisotropy Probe) which measured the fluctuations of the temperature of the universe – telling us a whole lot about its history. It is a very important experiment. Reuters actually agrees that this one is a pretty good bet. Another really good bet (in my opinion) is the Neutrino Mass experiment from Super-K. I bet on them in 2008 (and lost, as usual).

Another bet on Reuters is Ebbesen for surface plasmons: collective motion of light and electrons together on the surface of metals. While this is nice work, and Ebbesen is a good scientist, I think it is far from a Nobel.

Olaf Smits, in Dublin, mentioned a really interesting possibility. While a bit out of the box for a Nobel Prize in Physics, the fact that last year was a bit out of the box indicates that the Nobel committee is willing to break some rules these days. Olaf’s bet is that the prize will be awarded for the discovery of exo-solar planets. In the star-trek futuristic “this is our moment to discover that we are not alone” kind of way, I think a case could be made that this is worthy.

Singing

2010-09-12T12:45:00.000-07:00

A long time ago (in a galaxy far-far away)...

…I had a more musical life. I sang in choirs, played in orchestras, played in multiple jazz bands, classical chamber ensembles, and occasionally appeared in marching bands, handbell choirs, and even the stray pit-orchestras (swearing never-again each time). I called myself a “musical slut” because, more or less, I would play anything anywhere any time (thank you Dereth Phillips, where-ever you are, for coining that delicate phrase). These days, mostly just because I have way too many other things keeping me busy, such devotion to music has faded from my life.

Now, as mentioned in this previous post, all spring I heard many details of Christiane’s woes planning her wedding. One of the many things she worried about was the music for the wedding ceremony – she wanted a full choir in the chapel. When I confessed that, yes, I do read music well, and yes, I did once sing in a real choir, I was quickly drafted for the chapel choir and handed a stack of music to learn. Only then did I realize that the last time I tried to sing seriously was during the Reagan administration. I was unsure if the equipment was still even remotely functional.

To begin with, my voice was never great – it had a weak tone and my singing range was poor. I could never even get close to the top of the tenor notes, and I was really really weak down by the bottom of the bass notes. And this was years ago when I actually worked on my voice to stretch my range. Furthermore, I had a bad tendency to miss pitches. Not that I didn’t realize when this had happened – my ear about these things was pretty good. But I’d land on the wrong pitch and struggle to fix things – ending up either spontaneously changing keys or sounding a bit like a trombone doing a wa-wa as I slid between pitches.

Nonetheless, wanting to contribute to this wedding, I accepted the challenge from Christiane. I was fairly confident that I remembered the main secret to learning music – practice, practice, practice. If you study a piece of music enough, until it was like you had written the whole piece yourself, you can’t go too far wrong. (So I hoped).

First of all, I needed a place to practice: preferably a place where no one else would be listening to me singing --- because I was pretty sure that, at least to start with, I would end up sounding like a walrus in heat. A place to practice was harder to find than I had expected. It would have been great if I could have also found a piano to help me out, but alas, random pianos are pretty hard to find when you are on the road. The best practice room I found as the wedding approached was in my office in the Hamilton Institute. I would show up to work very early in the morning (before all the commuting Hamiltonians showed up) and make a whole lot of gargling and warbling sounds trying to learn my music. Then I did it again late at night after all the Hamiltonians went home.

So I spent many hours singing full volume in my office. It would kind of go like this: I would sing two or three measures; then listen to the relevant measures in a recording of the piece; then say out loud “crap, that’s not right”; read the music again (wishing I remembered my solfege better); then try again; then listen again; then curse again; and so it went on. Unfortunately some of the pieces I was supposed to learn had some tricky harmonies – and it took quite a bit of trying and cursing before I made any progress. To make my life worse, the bass parts frequently went either too high or too low for my voice – and as predicted, walrus noises came out instead.

Unfortunately, during these exercises, I was never quite sure that the Hamilton building was empty. So I’d be mid-walrus-sound and I’d see a Hamiltonian looking into my office with either a curious, or sometimes a rather perturbed look --- a perturbed Hamiltonian, as it were (that’s another physics joke). At that point I would put away my music and start on my usual physics work as if I had no idea where the walrus sounds were coming from.

Anyway, after quite a few days of this (hoping that I would not get kicked out of the building for disturbing the peace) I actually started to feel like I had a pretty decent handle on most of the music, and my vocal range was getting just a bit better – now being almost able to convincingly hit most of the high and low notes. Nonetheless, I was also increasingly hoping that the other bass in the choir (there would be only two on a part) would be a strong singer.

The choir would only have one hour of rehearsal just prior to the wedding ceremony. So on the day of the wedding, dressed in my wedding gear, I showed up early and started warming up my voice before the rehearsal. The choir consisted of 5 genuine friends and relatives of the betrothed, and 5 hired guns to fill out the parts – along with a conductor and organist from Somerville college (the organist is a bit famous around Somerville for being the best organist ever to set foot in the place – so I knew we would be fine in that respect). Within about 30 seconds of singing, I knew that this whole adventure was going to be no problem. The voices in this choir were wonderful --- all I had to do was not completely screw up and everything would be fine. The other bass (a childhood friend of Christiane’s named Martin) was a very solid singer and all I had to do was follow him (Thank you Martin!). I was probably the weakest voice in the choir by a good margin. It was very fun to sing with such a talented group.

So here were the pieces that were part of the service:

The first song at the beginning of the service was a modern hymn or something of the sort. I was a nice tune, although it sounded to me a bit like the kind of song you might hear at a Christian youth-group convention or up-with-people concert. It is in German so I have no idea what it means, but I strongly suspect that the words are in similar spirit to the youth-group-esque “we should all love each other” blah blah blah. This is not the actual arrangement we sang, but it gives the right feel of the kind of harmonies that were used (although it was a piano rather than electric organ accompaniment). To my taste, the best version of this song on the web is this rather simple version from a plain girl with a nice but not particularly spectacular voice just singing and playing guitar. It sounds a lot less like “up with people” this way. Kudos to her whoever she is.

The next musical part of the service was this standard German hymn. I was told that the Germans in the audience would fully expect this one to be sung.

During the bulk of the religious part of the service there were a bunch of little Kyrie-s interjected between the Greek orthodox priest’s singing of various bible verses. This was only a problem because the priest would pick some random pitch out of the air and we were supposed to come in on four part harmony with respect to his random pitch (it worked only about 70% of the time).

The hardest of the pieces came near the end of the service: The Lord Bless You and Keep You -- a very beautiful but difficult tune by the well known (still living) choral composer John Rutter. The harmonies on this one tested even some of the good singers. I really suffered to learn this. The piece also gave the sopranos a nice chance to shine (and indeed some of the sopranos had wonderful voices).

Finally, the majestic conclusion of the service, and my favorite of the pieces by far: “Lord in Thee Have I Trusted”, by George Frideric Handel. This piece, the conclusion of his “Dettingen Te Deum,” is a magnificent work meant as a celebration of a military victory as much as in praise of God. Considering the level of organization that went into putting together the wedding ceremony, the spirit of military victory seemed appropriate.

The piece begins with an alto solo which was to be sung by our common friend Sabine Müller (lecturer in modern languages). I’ve known for a while that Sabine took singing lessons, but for some reason it never really occurred to me that she might actually have a great voice (oh me of little faith). During rehearsal when we launched into this work and I heard her sing this solo for the first time I admit I was rather shocked by how good she sounded. Then when the rest of the choir came in with the strong sopranos, 5 part harmony, and organ accompaniment, the whole thing knocked my socks off.

So in the end my experience singing for this wedding went really well (meaning, it didn't sound like a walrus). It was fun contributing to the event and I realize I have missed the feeling of being part of a musical ensemble. Maybe I’m even so inspired that I’ll join a choir. Then again, joining choirs in Oxford can be bad for your health, as the famous Inspector Morse once discovered.

In regards to my previous post

2010-09-12T00:31:00.003-07:00

I received this plot from my brother Rob.

I think there needs to be less green.

Hamiltonians

2010-09-11T04:03:00.000-07:00

Whenever I visit the National Irish University at Maynooth (which I have been doing quite a lot recently) I am loaned an office in the Hamilton Mathematics Institute, not to be confused with this Hamilton Mathematics Institute, only a 45 minute train ride away. Both of these institutes are named after Ireland’s most famous mathematician and physicist, William Rowan Hamilton. If you have an office in one of these institutes you can call yourself a Hamiltonian.

And if you take the train into work in the morning then, because of you, all the other Neanderthals on the train will never evolve --- because they commute with a Hamiltonian.

If you did not get that joke, you are not a physicist.

I'm not making this up....

2010-09-10T12:28:00.000-07:00

... flying into Stockholm the girl sitting next to me had a dragon tatoo. On her ankle though. I tried not to make her angry.

Tying the knots

2010-09-09T14:45:00.000-07:00

No, not another talk about the mathematical theory of knots. Here I’m talking about the other knot – you know the one I appear to be allergic to – marriage.

A fair number of people get married right out of high school. More get married just after college. Then some more a few years after college. In my late 20’s and early 30’s, I must have gone to half a dozen weddings per year. My one nice suit got a lot of action. But by my late 30’s pretty much all my friends were either already married or, like me, didn’t appear to be the marrying type. Between 2005 and 2009, I’m not sure if I went to even a single wedding (er.. ok I think one in 2006, Ren?). Most days I can’t even remember what color my nice suit is, or where I put it for that matter.

Then in the year 2010, long after the wedding rush appeared to be completely over, all of a sudden 4 wedding invitations appears on my desk simultaneously! Here’s the list of the people to whom congratulations are due:

Carobe Hart and Nick Read:

Nick is a friend and colleague (a professor at Yale) who I have known for many years (He is also one of the few people around who I consider to be much much smarter than me – most people are only much smarter, but not much much smarter). Unfortunately, their wedding was scheduled right in the middle of the teaching term this last spring and it was humanly impossible to make it to the wedding and still fulfill my teaching responsibilities. I’ll make it up to them somehow.

Terrie Cooney and Rob Grainger:

Terrie is a good friend from back in New York, but as luck would have it, we both ended up in the UK (she’s in London). I met Terrie playing Frisbee very shortly after I moved down to New York in 1997 or so. We had a terrific little group of people who would get together every Sunday to play. Over the years we complained to each other an awful lot about being single. I really would have loved to have been at her wedding this summer. I’ll have to make it up to them as well! But unfortunately their wedding was scheduled at essentially the exact same time as …

Sarah Israelit and Nathan Roe:

Sarah is a friend of mine, originally from college, but we only became close many years later. I felt deeply invested in this wedding because a few years earlier when she had just started dating Nathan, I got almost daily panicked emails about “He doesn’t like me enough! I need to have a talk with him! I’m not sure this is working out” … and I sent many many an email back saying “Chill out. This is going great. He’s totally into you. Just relax.” (As if I really had a clue.) It was a great vicarious victory that it all worked out. I attended the beautiful wedding this July in Portland Oregon.

Christiane Riedinger and Luke Kontogiannis:

Christiane is the first new friend I made after moving to the UK. (“friend” is defined as a person who you can call and say “lets go get ice cream” at any random time). Through Christiane I met Luke, and a bunch of other nice folks too. (Pictures of them and their posse are here). This was another wedding that I felt very very invested in. Since I hang out with them very frequently, I heard an awful lot about the trials and tribulations of planning a wedding this year (actually they planned three weddings: one in Germany, one in Greece, and the big one in Oxford). The logistics of all this sounded to me to be more complicated than planning the invasion of Normandy. Last weekend they finally had the last of the three weddings in Oxford, and amazingly, everything (even the weather) was beautiful and it all went with not a single glitch. Another great victory! The bad news is that the two of them are moving to Cambridge in only a few weeks. Maybe they won’t like it and they will decide to move back. We do have better ice cream I’m sure.

Who Killed Hugo?

2010-08-23T10:30:00.001-07:00

A few weeks back, I lamented the death of my pet spider, Hugo, and I wondered what might have killed him. One of my thoughts was that he met another spider who was just a bit bigger and nastier than he was, and they had a bit of a spider-rumble. But Hugo was a pretty big guy, and I couldn’t imagine any spider hanging out in my house who was all that much bigger than Hugo.

Then I went away to the states for a few weeks. Upon my return I discovered that, not only was there a ginormous humungo Godzilla-spider hanging out in my bathtub, but he was acting like he owned the place!

I think I found Hugo’s killer!

I eyed him accusingly but he just snarled back. Well, this bathroom was not big enough for the both of us. So I left. I mean this guy was really big! Upon throwing a ruler near him I determined that his wing-span broke 6.5 inches. I did try to photograph him (with a telephoto from half a mile away. I didn’t want to get anywhere near this thing). I apologize that the photo is so bad that it is hard to see how damn large this thing was. But believe me, he could have eaten a large rodent.

I knew that I had to find a way to eliminate this demon-spawn. I thought about an exorcism, but not being religious – yet still being frightened to death when I watched the exorcist, I decided that this was not the right approach.

I armed myself with some serious heavy ammunition – all the shoes I owned. I stood out in the hallway, a good distance from the beast, and catapulted the shoes in his direction. After the first shell landed right next to him, he knew he was under attack. He scampered to the other side of the bathtub. Ha! Unfortunately he still had a spider-sized brain, and he did not realize that the other side of the bathtub was much easier for me to hit. With the second shell (my old hiking book) I fired and squashed him flat. I waited for a few minutes to see if he was planning on throwing the boot back at me. But after a few more minutes I determined that he really was deceased.

So it was that I avenged the death of Hugo.

Right now I am off in Ireland for a few more weeks. I'm wondering what new monster is going to be living in my house when I get back.

The Girl Who Played with… Euclid’s perfect theorem:

2010-08-21T08:26:00.000-07:00

Like most of the northern hemisphere, I’m in the middle of reading Stieg Larsson’s books “The Girl with the Dragon Tatoo” series. In the second volume, (“The Girl who Played with Fire”) our heroine, the punked out antisocial hacker, Lisbeth Salander, gets absorbed in recreational mathematics.

Now, in almost any popular novel, when the author starts delving into math, I am usually pretty familiar with whatever theorem, or unproven conjecture the author is mentioning -- frequently much more so than the author. I applaud the attempt to bring more science into popular fiction, but I don’t usually learn much from it.

However, on page 21 of the “The Girl who Played with Fire” the author mentions an ancient – and very beautiful! – theorem by Euclid, which rather shockingly I had never seen before. (A major gap in my education!) I scratched my head for a moment, then figured out Euclid’s proof (despite the fact that Lisbeth Salander sort of gets it wrong).

First of all: Here is the statement in the novel:

She was fascinated by Euclid’s discovery in about 300 B. C. that a perfect number is always a multiple of two numbers, in which one number is a power of 2 and the second consists of the different the difference between the next power of 2 and 1. This was a refinement of Pythagoras’ equation and she could see the endless combinations

6 = 2^1 ( 2^2 -1) 28 = 2^2 \times ( 2^3-1) 496 = 2^4 \times( 2^5-1) 8128 = 2^6 \times ( 2^7 -1)

She could go on indefinitely without finding any numbers that would break the rule.

(Yes, Larsson likes to write in Italics). OK, now the proper statement of the theorem.

Definition: A perfect number is a number where the sum of the number's factors adds up to the number itself. For example:

The factors of 6 are 1, 2 and 3. 1+2+3 = 6 so 6 is a perfect number.
The factors of 28 are 1,2,4,7,14. 1+2+4+7+14=28 so 28 is a perfect number
and so forth.

Euclid’s theorem: IF (2^k-1) is a prime number THEN 2^{k-1}\times (2^k-1) is a perfect number.

Salander does not mention the IF required of this theorem, but note that on her list of perfect numbers, she lists k=2,3,5,7 which are cases where (2^k-1) is prime. This type of prime is known as a Mersenne Prime]. How Euclid proved this theorem is beyond me. He was brilliant, but he did everything with geometry – and very little algebra (which is how I intend to prove it).

Almost 2000 years after Euclid’s proof, Euler proved that if an even number is perfect, then it is the form given by Euclid’s theorem. It is still not known if any odd perfect numbers exist --- although if they do exist they have to be ginormous since it has been proven that no odd perfect numbers exist less than 10^{300} . Assuming there are no odd perfect numbers, then there is exactly one perfect number for each Mersenne prime. It is not known how many of these there are.

OK, a quick proof of Euclid’s theorem: Consider the number 2^{k-1} (2^k-1) . If p = (2^k-1) is prime, then the only factors of (2^{k-1})p are

1,2,4, \ldots, 2^{k-1}

and

p,2p,4p, \ldots, 2^{k-2}p .

Now the sum of the series

1 + 2 + 4 +\ldots, + 2^{k-1} = 2^k -1

And similarly

p + 2p + 4 p + \ldots + 2^{k-2}p = p ( 1 + 2 + 4 + \ldots 2^{k-2}) = p(2^{k-1} -1)

So the sum of all the factors of the number gives

 (2^k-1) + p(2^{k-1}-1) = (2^k-1) + (2^k-1)(2^{k-1}-1) = 2^k(2^{k-1}-1)

which is the number itself!

Harvard is Easy – Almost

2010-08-12T08:31:00.000-07:00

This year’s hiking/camping trip with Carissa and Lin was to Mount Harvard –- the third highest peak in Colorado at 14,420 feet (4,395 meters to those who insist on Système-International d'Unités). It is the fourth highest peak in the 48 states behind California’s Mount Whitney, and Colorado’s Mount Elbert and Mount Massive.

You can read about last year’s Hiking trip on this page and this page (I apologize that the pictures are now defunct). Given that we failed to reach a summit last year, we decided on a simpler climb this year. Harvard is listed on the web as a clearly marked trail with little, if any, scree to slog through, making it a high, but relatively easy climb.

Our intent was to hike a few miles into the park on Friday and set up camp in between Mount Harvard, Mount Yale, and Mount Columbia of the Collegiate Range of the Sawatch. Then on Saturday we would climb Harvard, and on Sunday we would do the slightly smaller Columbia, and also walk back out to the trailhead by nightfall.

As planned, our hike started on Friday with full packs. We walked a few miles up the trail (gently uphill) until roughly the place where the trail splits towards either Harvard or Columbia. We set up camp near the fork in the road. The campsite we found had clearly been used by many before – it was perhaps the softest and flattest dirt I’ve ever seen anywhere in any woods. Add to this a standard thermarest air mattress and a thick sleeping bag, and quite frankly my tent was better than the beds I suffer through in many a hotel. I had no complaints whatsoever about comfort.

This was the view from our campsite. For a while we thought that the mountain in this picture is Mount Harvard, but it isn’t. I think it is known as Birthday Peak.

Carissa and Lin were dead-set on not eating freeze-dried camping food this year. So the first night’s dinner was curry-cous-cous with tofu and raisins and cashews and some broccoli soup. It was terrific. We had enough left-over cous-cous for about two days worth of breakfast and then some. After dinner we dove into our respective tents to try to escape the evening feeding frenzy of mosquitoes.

Another observation about Colorado mosquitoes: Last year I noted that the Colorado breed of mosquitoes are a lot slower and dumber than the east coast variety. This year I will add the observation, that if they do manage to bite you, it itches far far less than in New Jersey. What sin did New Jersey commit in a past life to deserve fast, vicious, and itchy mosquitoes? Maybe they are a product of toxic waste --- sort of like Godzilla being created by nuclear waste.

Now back to hiking:

When hiking in Colorado, one should really be on the way down from the mountain by noon since thunderstorms tend to come in the afternoon and it is rather dangerous to be caught up high during a storm. Even given this restriction, it is actually possible to climb both up and down Harvard and then up and down Columbia all in one day, but only if you start insanely early in the morning. During the night we heard a few climbing parties slogging by in the wee hours of the morning, and we assumed this was their intent. We, on the other hand, slept luxuriously late, ate our cous-cous breakfast, drank some coffee, and started up the trail at around 7.

Having started the morning a fair distance up the trail already (and with no intent to do two mountains in one day) we did not feel pressed for time. As long as we kept slogging along at a slow pace, we felt we would make the summit easily by noon.

For several miles, the trail was an easy (albeit uphill) country walk. It was well marked and easy to follow and the terrain was about as smooth and clear as you could ask for. For this, we must thank all those people who don’t understand statistics very well. You see, upkeep of many trails in Colorado is paid for by the vast proceeds of the Colorado lottery. It makes me almost want to buy a ticket even though I do understand statistics more or less. In fact one of the topics of conversation on our hike was Baysian reasoning. (But don’t get the idea it was all intellectual conversation --- we had long discussions of which muppet videos were the best).

The smooth trail goes up the left of the picture above. Bear lake is on the right (Despite the name, we didn’t see any bears – but we were careful to hang all our food in bear bags nonetheless). In the background is Mount Yale. Just behind Bear lake is the little peak which we could see from our campsite (possibly Birthday peak).

A bit higher up, the trail became much more steep. But for most of the way (again thanking the lottery) it was an extremely good trail --- like walking up a very long flight of stairs. Of course, once we got above about 12,000 feet, we found ourselves huffing and puffing quite a bit due to the thin air --- about 40% less oxygen than at sea level. Step-breathe-step-breathe, we made progress slowly but surely. Aside from all the huffing and puffing, the climb was not really all that difficult for most of the way.

Along the way we saw a bunch of random cute animals, including Pikas and Marmots which are both fundamentally rats, but are also insanely cute. That's a pika above and a marmot below (the fat one). I still expect him to start singing "I'm all right... don't have to worry 'bout me".

Near the very top, the trail suddenly turned into a boulder field and finally stopped being so wonderful. In Colorado, hiking trails are ranked into “classes” describing how technical they are (See here for a description). Harvard is supposed to be a class-II climb, meaning that you rarely need to use your hands. However, over this boulder field (with some pretty exposed cliffs staring you in the face) it is probably class-III. Here's a picture of me a bit before the boulders really start getting serious.

Fortunately, the boulder field is quite short and we reached the summit with no real trouble – and well before noon. Here’s a picture of the three of us on the summit (Carissa is in front, Lin in the middle, and I’m hiding in back).

Some guy was on top smoking a cigarette and taking pictures with his iPhone --- and get this: he actually had reception on the top, so he was sending pictures as email. This photo was taken by his iPhone and sent directly to my Mom. Actually it is not such a bad picture. The picture would have been better if he could have backed up a few more feet to get more of a view, but then he would have fallen off a five hundred foot cliff.

In this final summit photo, I’m pointing to what I think is Mount Oxford. We had discussed climbing Oxford as well, but decided against because the trail is not supposed to be well marked – maybe I’ll try it next year. Actually it turns out that Oxford is the mountain further to the right in the photo (over my left shoulder). The mountain I’m pointing to is probably Mount Belford.

After a peanut butter lunch on top (jealously protecting our food from an eager Marmot), we started the long climb back down. From the top, the weather still looked clear so we had plenty of time to go slow downwards. (I climb down extremely slowly – Carissa and particularly Lin seem to have the genes of mountain goats and were able to go down at a much greater speed).

Despite my slower progress I nonetheless managed to twist my ankle on the way down. Crunch. Ugh. Fortunately it didn’t seem too bad and although it hurt a bit, it was no problem to keep walking on it.

As we got closer to the bottom, and the weather had still not turned foul, we felt free to linger even longer as we went along. Back down in the country fields we even took our time and sat by a nice creek for a while soaking our feet. At this point we had only about two relatively flat miles back to our campsite. Here I pose for a picture near the creek. Harvard is in the background.

Just as we were leaving the creek to head back to camp I commented “You know, Harvard was pretty easy!”. Well, unfortunately, it seems the mountain gods heard me. About a dozen steps after that my twisted ankle started making an unpleasant (and painful) crunching sound. Fortunately, Lin was carrying an Ace bandage which patched things up temporarily and I had little trouble getting back home. That will teach me not to insult the mountain gods.

So Harvard was easy, almost.

Back at camp, we started cooking dinner. This time it was mac-and-cheese with (dehydrated) tuna. Again yum. Although bringing real food is a bit more heavy than bringing all dehydrated hiking food, I’d vote that it is totally worth it.

While we had planned to climb Columbia the next day, considering the condition of my foot, this was not going to happen (at least for me). I was hoping that at the very least the ankle wouldn’t swell up too much, and I’d be able to hike out of the woods without too much problem the next day (being carried out would be rather humiliating). Carissa and Lin graciously decided that they would not climb Columbia without me (Actually it looked like a bit of a scree-fest anyway – the grapes were sour).

The next morning my foot was no better, but no worse either. So at least I would be able to walk out of the woods. We slept late, cooked breakfast (oatmeal), packed our tents and had a relatively easy hike back to the cars. Had a few beers by a river to celebrate our successful trip, and called it a day.

The Best Physics Lecture Ever

2010-08-10T12:21:00.000-07:00

Out in Aspen Colorado, a few times each summer, there are physics lectures aimed at the general public, given in the memory of Heinz Pagels. Many years ago I heard one such lecture on the subject quantum mechanics given by a friend of mine named Shankar (one name only) who is a professor at Yale. The lecture was both entertaining and inspiring and accessible to all (not just to the physics cognoscenti). I remember how impressed I was, and I thought how great it would be to be able to give such a performance.

Last year I was honored to be asked to give one of these Pagels lectures. I spent literally weeks preparing it, trying to live up to the high standard set by Shankar. The lecture went very well, and maybe I got close to his level, but still I have to give credit where it is due: his lectures are still the yardstick by which other physics lectures should be measured. Perhaps we should declare a lecture to be a milli-Shankar if it is one one-thousandth as good as one of Shankar’s lectures.

This summer, Shankar gave yet another lecture --- this time on the subject of relativity – one of the most beautiful subjects in physics. This lecture was even better than his previous one. In fact, it was perhaps the best physics lecture, on any subject, that I have ever heard!

Fortunately, you can find all of these lectures streaming on the web. While sometimes a bit is lost in the translation to low-quality streaming video, nonetheless, I think they are all worth watching.

Here is Shankar’s lecture on relativity.

Here is his lecture on quantum mechanics.

... and in case you missed it last year, here is my lecture

Bobba Hannah Sandusky

2010-08-10T08:53:00.001-07:00

My Great-Great-Grandmother, Hannah Sandusky, was a rather unusual woman. Having immigrated to Pittsburgh around 1860, she became known as “The Angel” to those she helped. To everyone else, she was known as “Bobba Hannah.” “Bobba”, or “Bubbe” is Yiddish for grandmother. It also means “Midwife”, which was her profession -– although she never accepted fees for her services. Over her lifetime she delivered many thousands of babies for the poor in the Pittsburgh area. Although she was horrible at keeping records, she managed to register over 3500 deliveries – and probably far more remained undocumented. Hannah also spent a lot of time doing other charity work, as well as the duties expected of Jewish grandmothers, such as matchmaking.

Thanks to some major legwork by several of my cousins (Kudos to Miriam Baker in particular) this last weekend in Pittsburgh we had the first ever reunion of the descendents of Bobba Hannah. Hannah and Louis Sandusky had eight children: three boys and five girls. Only four of the daughters had offspring, so the Sandusky name died out, and the clan became divided into Raphaels, Gordons, Schugars, and Simons. The clan is now spread out around the world, and until this last weekend, I had only met a tiny fraction of my extended family.

During this weekend I heard a number of interesting stories. There was the story of the funeral crashing cousin who ended up being locked in a closet by the undertaker; and there were many stories of my grandfather, who was frequently on the wrong side of the law but managed to always evade the feds one way or the other. But perhaps the most interesting story was how my grandmother met my grandfather.

In 1913, shortly after immigrating to Pittsburgh from Lithuania via South Africa, Eva Grabowski was told that an unusual event would be taking place: a funeral procession which was made up of both Jews and African Americans. Needless to say, this was Bobba Hannah’s funeral.

Here I quote from a transcript dictated by my grandmother a few years before she passed away:

I was standing on the verandah watching the funeral procession... On the other side of the road a young man was also standing on a balcony watching the procession where he spotted me. We became acquainted and his name was Ike Simon. He was a big man with a heart of gold and when he asked me to marry him I decided to accept, having in mind, if it didn’t work out, I would leave him and return to South Africa.

Well, it did work out, and I’m sure Bobba Hanna, the part-time matchmaker, would have been very pleased.

[Note: There is some confusion in the story as to whether they met at Hannah's funeral or some other funeral. It makes a better story this way].

Some Skunk Funk

2010-07-07T03:08:00.000-07:00

… that is the title of a famous Brecker Brothers Jazz tune. (See here for a great performance). Unfortunately, it is also what I discovered when I opened my suitcase after its damp contents had been fermenting for a week. (See here for the long story).

Nonetheless, I’m very happy to have the suitcase back. For a while I was sure that I would never see my snoopy T-shirt or my hiking boots again. A huge thanks to the nice people at the Benasque physics center for hunting down the suitcase. And also a huge thanks to Adam Nahum who hand-carried the suitcase back from Benasque to Oxford.

I've washed the stinkin jeans several times now and they are still a bit skunky and a bit funky... but they are recovering slowly.

The Short Life of Hugo the Spider

2010-07-03T14:35:00.000-07:00

A few weeks back, I returned home to my Oxford abode, walked into the bathroom and discovered an enormous spider sitting in the middle of the floor looking hungrily at me. Now, as I've mentioned before on this blog, I'm not really much of a fan of spiders. I immediately decided that the house was not big enough for the both of us and I went to get my trusty spider-destruction-device: My hiking boot.

As I planned my attack, I noticed that this spider was clearly a different breed from the enormous Shelob that I encountered last summer. Shelob was a brown and slightly hairy, totally ginormous, orb-weaving (and probably physicist eating), creature. The current spider (who unlike Shelob, was already inside my house), was a large black (and probably physicist eating) spider, who did not appear to have a web. This probably meant he was a hunting spider -- which meant he was fast and probably had good eyesight. So I snuck up on him slowly, and brought down the hiking boot with a very swift blow.

Unfortunately, the spider was quick --- quicker that the boot. It jumped out of the way, scampered to a corner of the bathroom and hid in a little hole (a spider-hole, as it were) where I could not get it. He won this round, but certainly there would be others.

The next day, when I came home from work, I was again greeted by the spider in the middle of the bathroom floor. Now, despite the fact that a spider's brain consists of only two ganglia, it had clearly learned that I was a threat. As soon as it saw me, it scampered off to its spider hole again. This behavior repeated itself almost every day for a week. I would return home, and as soon as it saw me it would run away. Never did I have any chance to splat him with my boot. Eventually, I conceded that I would be sharing my apartment with a huge black spider. He could have the bathroom during the day, but when I came home at night, he had to go back to his spider hole. Being that I was resigned to having a roommate, I figured he should have a name: Hugo.

I returned home from work every day and I would yell "Hugo, I'm home" (Hoping this would prompt him to pre-emptively evacuate). Sometimes when I was showering I would see him try to sneak out of his hole, and I'd talk to him. "OK, Hugo... you can look around a bit now, but when I get out of the shower, you better be gone again"... and usually he was. After a few weeks of this, he didn't seem quite so scary any more. He was clearly pretty frightened of me, and I started to feel bad about making his life so difficult.

So bit by bit, Hugo went from a physicist-eating monster to a harmless pet. He didn't seem to have any plans of murdering me in my sleep, so I stopped making a point of chasing him back to his hole. Not that I became a big fan of spiders overnight, but maybe Hugo was OK. At least he had personality.

Then one day I came home from work and Hugo was sitting in the middle of the bathroom floor as he often was... but this time he was half-upside-down and seemed to be having convulsions. Clearly he was a very sick eight-legged animal. I don't know much about spider-health so I just talked to him and encouraged him to recover. I figured the best thing I could do was probably just to let him try to recover on his own.

Sadly, the next morning, Hugo was stone cold. Somehow I felt a small twinge of sadness for Hugo. He was an exceptional spider --- if for no other reason because he managed to slowly make me not afraid of him. I still don't know what killed him. Two possibilities come to mind:

(1) Hugo could be (and probably was) Hug-ette. Some species of spiders die shortly after laying eggs. Possibly this was simply Hugo's time to go. (And possibly I will be meeting Hugo Junior in the near future).

OR

(2) Some other spider (or other insect) had taken Hugo in battle. While this may sound unlikely, given Hugo's unusual size, a few days later I spotted a much smaller, but very very quick looking spider who could possibly have done the job. I went after him with my hiking boot -- but I missed.

The Retirement of Dame Fiona: The Spell is Broken

2010-06-30T02:32:00.000-07:00

Over the last few weeks, there have been many goodbyes for Dame Fiona Caldicott who has been Principal of Somerville College for fourteen years and is retiring this summer. There have been numerous formal dinners, lunches, and so forth to see her off and to celebrate the years of her good leadership (At one I such event I even wore my first real bow tie – the kind you actually have to tie instead of clipping on – which only took me about an hour to figure out).

Now, Fiona is not one for giving long speeches, or listening to long speeches for that matter, but these things are hard to avoid when coming to the end of an era. Of these speeches given at these formal events, probably the best one was given by the JCR president (Junior Common Room – meaning undergraduate student body). It was in some ways long and rambling and it even had some cringe-worthy moments. However, it was also very heartfelt – and he was brave enough to say what everyone around the college had been thinking for the last few weeks: The spell is broken.

If you have been reading my blog over the last year, you will already know that the most important icon of Somerville College has for years been Pogo the cat. While Pogo nominally belongs to Dame Fiona, mysteriously no one would ever see the two of them together at the same time. This led to a common belief that Pogo is actually Fiona’s alter-ego --- and the reason that Fiona seemed so well informed about what was going on in every corner of the college was because she wandered the grounds, undetected, in the form of her cat.

But over the last few weeks, on numerous occasions people actually saw Pogo and Fiona together. I even saw it myself. Hushed whispers spread quickly around the college: The spell is broken.

You see, as Fiona bids farewell to the college, her need for such strong magic is no longer, so she and Pogo can now go into retirement at their regular home as a regular person and a regular cat.

My Stinkin’ Jeans: More Travel Troubles.

2010-06-29T01:16:00.000-07:00

After returning from hiking in Benasque I tried to clean off my muddy and soaked boots, jeans , socks, and shirt, and I hung them to dry overnight. Unfortunately, overnight was not nearly long enough for them to dry, so when I packed up to leave Benasque the next morning I wrapped the whole mess inside of my jeans, and stuffed the damp package in my suitcase. Hopefully the wet and somewhat stinky mess would not be able to infect the rest of my luggage too much during the 12 hour trip. I’d certainly have to wash everything again when I got to Ireland, but hopefully it wouldn’t be too nasty.

I then put my luggage on the bus from Benasque to Barbastro. The bus to Barbastro is a local bus, stopping at every other street corner for the two hour trip down the mountain. Each time the bus stopped, it opened its luggage hold, people got on and off the bus and put luggage on and off. When I got to Barbastro, unfortunately, my luggage was missing --- lost or stolen. I tried to communicate the situation to the bus staff, but being that my vocabulary in Spanish consists of only “hamburgesa” and “cerveza” I was not very successful. The bus to Barcelona left only a few minutes later and I knew that if I waited for the next one, I would miss my flight. So I jumped on the bus and started making a mental inventory of what was lost and what I still had with me.

What I still had with me:

Wearing:
Red t-shirt with an hbar on the front of it
Jeans
Boxers
Teva sandles
One fleece
Glasses
Watch

Carrying:
Laptop case
Laptop and Charger
Passport
Wallet (including several credit cards, and some euros)
Prescription Sunglasses
One Pen
One novel, unopened.

What was lost:
One new suitcase (Delsey was recently replaced)
One pair of wet and muddy Vasque hiking boots
Some jeans (one pair now wet and muddy)
Two nice shirts and a sweater from banana republic
A bunch of cruddy shirts
One snoopy tee-shirt (“borrowed” from my ex girlfriend)
One flying-spaghetti-monster tee-shirt
A bunch of mostly cruddy tee-shirts (one muddy)
Shorts (old)
One tweed jacket (old)
One pair of “Grinch who stole Christmas” boxers
Nine other pairs of nondescript boxers
One travel iron
One travel alarm
Razors, toothbrush, etc.

Looking at the list, the most valuable thing lost was probably the hiking boots and the suitcase itself (and the emotional value of snoopy, FSM, and the Grinch). If the luggage was actually stolen, I think the thief would be a sorely disappointed with his haul.

Late that evening I arrived in Ireland, and the next morning I stopped at the cut-rate department store and got myself some replacement shirts, boxers, toothbrush, etc. 2 euro for a t-shirt. Maybe I’ll buy a few more of them!

I tried to write to the Bus company in Spain, but I did not hear back from them (again, my limited knowledge of Spanish was probably a bit of a detriment, but with Google translate, I’m pretty sure I can make myself understood). I also wrote to the staff of the physics center in Benasque to see if they could help me. No progress yet.

I don’t know if my luggage will be recovered or not. Each hour it is gone, however, I imagine my wet and muddy hiking gear is fermenting just a bit more. Perhaps after a few more days of nasty growth, the damp jean and boots will be able to walk home by themselves. Or maybe they will be classified as a biological weapon and will be put on the no-fly list.

Update Monday Night: I just got an email from the Benasque staff saying that the bus company thinks they found my luggage! Yay!

Update Tuesday Morning: They discovered that the luggage is not actually mine. Boo!

Further updates will be posted as the story progresses.

Update Tuesday Afternoon: Reversal of fortune #2 : They think they have my luggage again. Yay!

A Busy Day at the Refugio

2010-06-28T09:32:00.000-07:00

High up in the Pyrenees, a six hour (sometimes terrifying) bus ride from Barcelona, there is a little ski-resort town called Benasque. Some genius named Pedro Pasquale had a brilliant idea of putting a physics center in this little town. In the language of physics, this center is in the same “universality class” as the Aspen center for physics where I will be again later this summer.

The Pyrenees are quite beautiful, and at least for the week I was there, the weather was mostly beautiful too. The Spanish locals are very friendly and have an enlightened view of life --- which includes a lot of partying and only mild work. The only negative thing I can say about the place is that the vegetarians amongst us seemed to be having a hard time finding much to eat (although the goat cheese was delicious). I, on the other hand, broke my recent vow to eat less red meat and enthusiastically gobbled down chorizo.

After giving a bunch of lectures at the INSTANS (Interdisciplinary Statistical and Field Theory Approaches to Nanophysics and Low Dimensional Systems) summer school early in the week, I relaxed for the latter half of the week, watched a lot of the world cup with the locals (and other enthusiastic Europeans), made much of my very limited Spanish vocabulary (which includes only the words “hamburgesa” and “cerveza”) and took the opportunity to go hiking a few times.

On Saturday, with no classes scheduled, a large group of students and postdocs (plus me) decided to take a long hike. (Some of these students were apparently out dancing at a disco bar until 5am the previous night, and still woke up at 9am to go hiking! Needless to say, dancing til 5am was out of the question for me). The intent was a 10+ hour hike starting in town and going up to almost a local high point (about 1500 meters of elevation gain, I think).

The mountains near Benasque do not look like the Rockies, or the Alps, rather they look like New Zealand. I’ve never been to New Zealand, but I’ve watched Lord of the Rings a bunch of times – and except for Sauron’s watchful eye and the absence of hobbits – the Pyranees look like middle earth.

On the way out of town we had to walk through a herd of rather loud, but not unfriendly, cows. These cows were not mooing, or even lowing, but they were positively bellowing. I’m not exactly sure what they were saying, but perhaps they meant to say “you idiots, can’t you see it is going to rain”. At the time the weather looked great, but…

After about three hours of hiking (and not *too* much elevation gain) we came to the “Refugio” - a tiny shelter by a clear mountain lake at a fork in the trail - where we stopped to eat our lunch. There were a fair number of hikers on the trail, and many of them had stopped in the same place. After a bit of planning, we divided into groups who intended slightly different hikes from there and set off for the hard part of the day. I ended up in the middle-speed group (which was fine with me, being too many years older than the next oldest hiker that day). After only another half-hour of hiking we made it to another mountain lake, and looking ahead, we saw the advanced party of faster hikers on the other side of the lake just starting the hard slog up the steep part of the mountain. Unfortunately, we also saw some ugly looking clouds coming in over the mountain. There was a bit of debate, but rather quickly we made the decision to turn back and try to get back down to the Refugio before getting completely pummeled by the storm.

Within only a few minutes the rain started. Then the rain turned to hail. Then the hail was accompanied by thunder and lightning. Then it just turned back into drenching rain. The trip down was probably almost as slow as the trip up because the rock had gotten slippery in places. By the time we made it back to the Refugio, we were all pretty much soaked to the bone. But alas, the Refugio (which was really tiny – maybe 8 feet on a side) was completely packed with other people who had gotten there first – 16 people in fact. So, a few of us were left out in the rain (I was given an umbrella to help me wait out the storm).

The rain continued far longer than I expected. After about another 20 minutes or so, the advance-group made it down to the Refugio and just decided to keep walking down. Being completely soaked already, and hoping to be able to walk on less slippery surface, I stayed up at the Refugio with the others waiting for it to let up.

An hour later, the sky finally cleared. Fortunately, it was not too cold out, so, although I was very very wet, I was not too uncomfortable (except for numb-ish hands). So we started the long wet slog home. On the hike down, we saw the cows again – who just looked at us and mooed happily “we told you so”.

PS: I saw a Great Pyrenees in the Pyrenees. It made my day.

Porcelain Heaven

2010-06-12T04:12:00.000-07:00

(This is not a joke about a toilet.)

The town of Meissen, outside of Dresden, has been the porcelain capital of Europe since 1710 when porcelain technology was discovered for the first time outside of China.

The historic town itself (founded in 1150) still has palaces, cathedrals, fortresses, and so forth. It was somehow completely spared during the second world war, but it was almost destroyed by neglect during the DDR era (“The government that creates ruins without weapons”). It is worth the visit if you happen to be in the area.

Despite the long history of the town, its greatest fame is its porcelain. About half the physicists attending QHSYST-2010 in Dresden last week made an excursion to tour the town and the famous porcelain factory. I think the tour guides were a bit taken aback that we physicists were there taking detailed notes (or at least I was taking notes) about the details of the porcelain process (being that most physicists don’t really care so much about dinner settings and the like).

So here is the rough process: Feldspar, Quartz, Kaolin, makes the base clay-like material. Underglaze dyes are mainly Cobalt Blue and Chrome Oxide. There are three bakings, 950 degrees C, 1100-1150 degrees C, 950 degrees C. The overglaze painting is after the middle bake. One obtains a 16% reduction in size after the hot baking. While the tour guide was very nice (a third generation porcelain-ite) very quickly we reached questions that the she could not answer and probably had never been asked before. I hope we (I) did not annoy her too much.

The porcelain products are all hand decorated – and hand crafted (if you allow molds within the definition of “hand crafted”). This makes them rather expensive. For example, this 200 piece dinner service (without the glassware or silver) will set you back 30,000 euro (36,000$) more or less.

A hand painted porcelain chandelier was 80,000 euro. Fortunately, the chandelier is hideously ugly and no one in their right mind should want one even if it were free. In fact, this is more or less my opinion of most of their products. Impressive art work, perhaps, but truly awful.

Now, you might think that my distaste for porcelain is just because I am an uncultured nerd... but in fact, I’m not the only one who thinks this. The famous german author Goethe, visited Meissen in 1813 and thought more or less the same. The following quote was translated for me by a nice tour guide:

“It is funny and almost incredible that there is nothing that you would want to have in your household. This is the oddest exhibition of everything that does not please and can never please again”

I fear the tour guide gave me this quote (without a hint of irony) thinking that it only showed how wrong Goethe was. There is a reason that Goethe is viewed as one of the true geniuses of his age.

Embarrassing moments include

2010-06-10T12:49:00.000-07:00

Last week my former graduate student Ilya Berdnikov stopped by Oxford for a visit. Although the weather was a bit inclement, I wanted to show him the sights of the city of dreaming spires. (My tour of Oxford is getting pretty polished --- you can see some of the highlights from previous tours here and here). Undeterred by the weather, we dressed in foul weather gear – rain jacket, umbrella, boots – and started on our way.

One key part of the tour is to go to the top of the tower of the Church of the Virgin St. Mary. On the way into the church tower, you walk through the church itself. As luck would have it, a choir was practicing there, so we stopped to listen. Recognizing the conductor and some of the singers, I realized it was the Somerville college choir. (They did sound very nice in that space!) Bells should have gone off in my head at that point, but alas, they did not. I should have wondered why the Somerville choir was practicing in that church on that particular day.

We climbed up to the top of the tower and looked at the scenery for quite a while. The weather was perhaps starting to clear. It was cold and a bit drizzling but not uncomfortable up at the top. I mulled over “is that building Lincoln college, or is it that building?”, and pondered other geographical mysteries for quite some time. Then we started the long descent down.

As we neared the bottom we could hear the organ playing in the church. (I very much like organ music). The organ sounded a bit like a funeral precession. Loud bells should have been ringing in my head at this point, but alas… they still did not.

I opened the door to exit from the tower into the church and immediately stepped into a precession of my colleagues –- the Fellows of Somerville college –- coming into the church for a memorial service which I was supposed to be attending. The service was for the college’s former principal (and well known british spy) Baroness Daphne Park (you can read a very interesting obit here). All of the other Fellows of the college were wearing academic robes and black tie. I was dressed in my blue raincoat and hiking boots. I immediately turned bright red, turned around and jumped back into the church tower and closed the door behind me to hide in shame. I had completely forgotten that the memorial service was being held on that particular day. You might think that the choir and the organ music would have jogged my brain, but alas…

Anyway, we hid in the church tower for a moment trying to decide what to do next. It turns out that there is a back exit from the church tower into the café next door. Unfortunately, the exit door was locked, but I bashed on the door and pleaded with the café workers until they got a key and let me out through the escape hatch. But (alas), on the way out, I was caught by another fellow of the college who had been late for the precession (but was at least appropriately dressed) and who appeared to be trying to sneak into the church in exactly the same way I was sneaking out.

I’m not sure how many of the college fellows actually saw my faux-pas. I’m certain a few did. Fortunately, I think can get away with a few blunders like this one just for being an American.

Congratulations to Rahul Roy

2010-06-06T23:23:00.000-07:00

First of all, don’t try googling his name --- there is a famous Bollywood film actor named Rahul Roy. That is not the guy I’m talking about.

Last week Rahul Roy, a postdoc at Oxford (in my group, although mainly he works independently), won the prestigious McMillan award. This is a big deal. The award is presented to one young condensed matter physicist each year. (This year it was split for the first time ever, with Liang Fu, now at Harvard, winning the other half).

The work that was cited in this award was the theoretical prediction of Topological Insulators --- something I have blogged about several times before. See, for example, here.

Things they don’t teach you in graduate school include: Catering.

2010-05-14T12:20:00.000-07:00

I’ve often complained that many of the skills you need to succeed in science are not taught in graduate school. Rarely does anyone receive formal instruction in teaching, presenting, grant-writing, managing a group, or schmoozing --- which are all pretty important skills for practicing academics. Most of us eventually learn to do these things competently, even though these are not necessarily the things that we are really good at.

At Oxford, academics are expected to have skills that really stretch into the realm of the completely ridiculous. The reason for this is that each college is run (and in some ways owned) by its governing body –-- essentially the tenured professors (see the discussion here). As a result, we professors have to make decisions on everything from investing the college endowment to hiring the gardeners. We are certainly smart enough to realize that we know nothing about these things and as much as possible we try to consult people who actually do know something. Nonetheless, there are inevitably times when we have to ring-in on something that we know absolutely nothing about.

This week, Somerville College held interviews for a Deputy Head of Catering. In assembling the interview panel, it was deemed necessary that a certain number of members of governing body sit on this panel. Having avoided many odious tasks over the last year, this time I drew the short straw. So this week I sat through an entire day of interviewing caterers… as if I have any clue what these guys do. I suppose in some ways it was interesting: by the end of the day I learned that the caterers at Somerville actually do a whole lot --- from putting together the food for the students, preparing fancy formal meals, holding events and conferences, dealing with the health authorities (who randomly come by and inspect everything) and so forth. Obviously what I actually know about this profession is pretty close to nil. Yet I was still asked to form some sort of opinion about the candidates. Fortunately, there were two people on the interview panel who actually did know what they were looking for. I think I was there just for --- well, actually, I’m not entirely sure why I was there, but somehow it was deemed important that I be there anyway.

Never a dull moment…

For your reading pleasure

2010-04-29T12:18:00.000-07:00

Fiona Burnell and I have been working on a rather massive paper for almost two years now. Finally, this week, we declared it finished.

If you want know what it is about, you can read my short description here – or you can read the complete paper here, or you can read the reader’s-digest-massively condensed version here. If you don’t want to actually read it, you can just marvel at the cool figures.

Now, this is not the paper that has taken me the longest to write (My record in this respect was this paper, which I started with Gunnar Moller before he started graduate school, and we finished it almost exactly five years later when he was a postdoc). What is unusual about this paper is how long it is --– 35 small print pages: almost a third longer than any other paper I have ever published (not counting review articles). It feels really good to have it done.

What now? Time to write the next paper! .. and if you are the kind of person who reads this stuff, just wait til the next one… it gets even cooler soon!

The Bells

2010-04-25T03:22:00.000-07:00

When Paul Wiegmann visited Oxford early last year, he stayed in the cushy accommodations of the very weathly St. John’s college. Despite the luxury, he was seriously perturbed by the Bells of St. Johns.

“At 1 am they rang and woke me up. Then at 2am they rang twice and woke me up. Then at 3am they rang three times and woke me up…” ... and so forth.

My house (or “terraced”, as it is called) is very close to St. Barnabus Church. There are also hourly chimes at that church all night long, but I’m just far enough away that they don’t disturb me while I am sleeping (a block away is about enough, being that I’m slowly going deaf).

Bells at Oxford are just a fact of life you get used to. In addition to hourly chimes from everywhere, you frequently hear a bell cacophony that continues on and on for minutes, or even for the better part of an hour sometimes. You rarely know where these things are coming from, or why they are ringing in the first place. Many of the 40-something-odd colleges and halls have bell towers, as do many of the dozens of churches scattered around Oxford.

Perhaps the most impressive, if not the loudest, set of bells is at St Giles church, which is conveniently squeezed between the Theoretical Physics department and Somerville College, and can be heard very clearly from both. The bells in this church have an impressive history. The tenor F# bell dates all the way back to 1632 and bears the inscription

FEARE GOD HONAR THE KING 1632

“Honar”-ing the king probably meant “do what the king tells you if you want keep your head”. “Feare”-ing God probably also meant, “do what the church tells you if you want to keep your head”. Perhaps “Learn to spell” would have been a good addition to the inscription as well.

Despite the ruckus caused by the frequently ringing of these bells, I confess to having a soft spot for bell-ringing. Back in high-school in Rochester New York, I was heavily recruited by several churches to be part of their bell-choirs. I was considered a choice recruit because I could read music well and, as an agnostic jew, I was always available on Sunday mornings. Admittedly, this was handbell ringing (See here or here), not real quasimodo-style bell ringing, but I’m not sure that any church in Rochester New York even has a proper bell-tower for that. The handbells were popularized as practice tools for their larger counterparts, but have now taken on a life of their own – particularly in sacred music, and in places where they don’t have real bell towers. At any rate, some of these bell-choirs were really fun to play in and they had talented musicians as their leaders. The down side was that I occasionally ended up having to sit through church services --- I guess the corresponding benefit of this was that I finally learned a bit about what goes on in churches (although it also more or less cemented my opinion that I was not really missing much as a non-church-goer). At any rate, I think I may have been the only agnostic Jew in high school who could quote new testament scripture.

Organization and Lack Thereof: A Reflection on How Research Works

2010-04-25T01:53:00.000-07:00

Organization is not my strong point. Anyone who has seen my office, or my apartment can vouch for this. Starting my new life as a professor last year, I was worried that lack of organization – particularly in running a research group - might be my downfall. For me, in fact, the entire concept of research is fundamentally disorganized – and I’ve always felt that this is a good thing, since random wandering encourages random discovery.

Some professors do manage to run large organized groups. I think the larger the group, the more organized it has to be. Some even have detailed hierarchical structures, including lieutenants (pronounced “leftenants” over here), sergeants, and so forth. Each person has a unique and well defined project. Higher rank members oversee lower-rank members. They have group meetings periodically where one person reports on their progress, and research gets done very methodically. The top dog doles out the projects and sets the overall directions. The foot soldiers take their orders and produce the results.

But for many theoretical physicists that I know, this is not at all how research works. A more accurate description is that a researcher has some general field of interest and they simply mess around with ideas in that field until they figure out something interesting to work on. They work on this interesting idea for a while, two steps forward, one step back, and eventually do manage to make progress. But this type of messing around is not something that is easily organized. And it is particularly hard to oversee someone else’s messings and decide whether they are messing around correctly or not. Such researchers tend to have smaller research groups and tend to interact much more closely with their students and postdocs.

Of course when it finally comes time to publish discoveries, I do think it is very important to present a very organized picture of what you have found, and I do agonize over the organizations of my publications and talks. But this is more an exercise in covering your tracks and making it look like you knew where you were going all along.

Just sayin'...

Volcano Woes

2010-04-17T12:06:00.001-07:00

I’m used to having my travel schedule disrupted by all sorts of things: Thunderstorms, Snowstorms, Incompetent airline companies, Needing to saw a hole in my bed, and random other unforeseen circumstances.

This week’s unforeseen circumstance was a volcano – mount Eyjafjallajokul in Iceland. If you have not been following the news, I’ll fill you in: The massive amount of ash spewing from the volcano has dispersed across the skies of Europe and has completely shut down all air travel for thousands of miles around.

It figures it would be a volcano in Iceland. First they ruin their own economy, then they destroy the travel industry of the entire continent. This is hardly surprising from a country whose main industries are “fishing, dragons, and screaming” (if you don’t get that joke, look here Although if you live outside the US, you might not be able to stream this brilliant video. Try looking here).

Anyway, at the time of the eruption, I was in Ireland – just an hour flight from home. But alas, for the last three days, and for the forseeable future, no planes have been, or will be, moving. So the only way off the island was by Ferry.

(Random aside: I was amazed to discover that only about 12,000 years ago there were land bridges from Ireland to UK and from the UK to continental Europe. But alas, these bridges are now long gone).

Getting a reservation on one of the ferries was no mean feat. There are precious few ferries, and they quickly started to fill to capacity. (“Capacity” turns out to be far more than they can handle, since on a typical day, I’m told they run at about 10% of capacity – if that). Along with thousands of other people in the same predicament, I started franticly surfing the web trying to get a reservation. (Calling was beyond hopeless). There were very few web sites that would take reservations any more, and many of these sites were freaking out and crashing from the extreme traffic. After a few hours of searching, finally, for a brief moment, Fortuna smiled upon me, and I managed to nab a ferry reservation to Holyhead (Batman) in Wales, for the next day at 8am.

So at 6am Saturday morning I left Maynooth Ireland to go to Dublin Ferry Port. The scene there was hardly to be believed – people lined up to get on the ferries as far as the eye could see. You would think it was a rock concert or something.

Loading the Ferry, the Ulysses (appropriately enough for a Dubliner), was smooth enough. Show your reservation number, and walk right on. There was a guy there grabbing everyone’s baggage and throwing it onto a baggage carosel. Had I been thinking I would have refused to part with my luggage, but at the time I was just happy to be getting on the ferry. Huge mistake (more on this below).

The Ulysses itself is actually very nice. It seemed like it was actually a slightly re-configured posh cruise ship. Imagine the Love Boat, but a bit smaller. Now imagine taking the Love Boat and jam packing it with 1500 tired and grouchy people in a space more suited to about 100 people. (For those who might be interested, I spent the trip sitting in a corner reading appendix E from this massive article which I had the foresight to print out the night before. I only wished I had used a slightly larger font – my eyes are getting too old for the “print reduced by a factor of 4 so you don’t have to carry around too much paper” trick).

The seas were remarkably smooth, and the trip was very quick. This was not a coincidence. If the weather had been windy or rainy, the volcano ashes would have dispersed or found their way down to the ground as rain and air travel would have resumed. Alas, the unusual streak of fair weather and smooth sailing in Europe this month seems to have come at just the wrong time.

On the other hand, what was decidedly not smooth was the situation at Holyhead. The baggage carosel at the Holyhead terminal was set up to handle about a dozen bags, maybe a hundred,… not ten thousand. The masses of humanity squeezed into the arrival hall and complete confusion reigned. Just when we thought that maybe a few people were starting to find their luggage, the next ferry docked and complete confusion started all over again.

When I finally found my luggage after about an hour and a half (No exaggeration – I was cursing myself for stupidly allowing my luggage to be separated from me in the first place) I then had to find my way to the train. Of course there were thousands of other people with the same idea. The confusion was so complete in the station that it wasn’t even clear where the line for the train started and where it ended. I wandered around in the confusion for quite some time (you might think they would bring out a few extra police or rail workers to help with the situation, but no). As I got more frustrated, I debated getting a cab to take me to anywhere else besides Holyhead so I could reconsider the problem there. Just then a security officer came along and declared that I was standing in the line for the train tickets and just beyond that was, the train platform. He pointed only about 50 feet away to what was supposedly the front of the line. This was another rather lucky break. In only about 40 minutes I made it to the front of this line, grabbed my ticket and walked onto the next train. In another stroke of luck, the next train was direct to Birmingham – whereas many would have required at least two transfers. Fortuna was certainly smiling on me now.

I hesitate to think about how long some people must have been waiting to get on the train. The line stretched so long it was probably hours and hours before some of the folks at the back of the line got out of there.

Anyway, from Holyhead the journey was pretty simple. 4.5 hours to Birminham, short layover, and an hour from there to Oxford. I made it home by about 8 pm. I typically make it home from the US in much less time.

Next travel disruption? Earthquakes? Locusts?

Lecturing

2010-04-13T12:09:00.000-07:00

Much of the teaching at Oxford is done in “tutorials”: one, two, or three students at a time with one professor (A similar system exists at Cambridge with the one important difference being that they are called “supervisions.” Oxford students insist that the word “tutorial” is better because you can shorten it to “tute”, which they do more often than not).

The tutorial system is very manpower intensive, but reasonably effective in forcing the students to keep up. I’ve been handling a full load of tutorials since the first day I joined here last year.

In addition to tutorials, there are also regular lectures. Last term, (Hilary 2010) I gave my first lecture course. It was a softball intended to ease me into the hard work of lecturing: a graduate course with only one lecture per week for 8 weeks. (Graduate courses are considered easier to teach as there are fewer students, the students are all very motivated, you can talk about whatever you want, and if you do a bad job there is far less carnage).

For those who are interested, the topic of this course was “Topological Matter”. If you want more details you can check out the web page here. (Feel free to try some of the homework assignments for fun. Many of the problems can be done without having attended lectures, and they are meant to be fun – well, fun for physicists).

As I probably should have expected, in 8 lectures I made it through about a third of my intended course outline. For a graduate course this is not so much of a problem. The course is meant to introduce the students to certain topics that they want to know about. If they learn fewer topics, but learn them better, that is fine too. Maybe another year I’ll teach the remaining two thirds.

Next year, however, I will be lecturing Condensed Matter (aka Solid State) Physics for 180 undergraduates (give or take). In this case the syllabus is very constrained, and I am required to cover certain topics –-- as these are the topics that will be examined. An interesting feature of the Oxford system is that the lecturer is not the person to write the exam. Instead, a syllabus is agreed upon before the course starts, and the exam is written based on the syllabus. The lecturers, as well as the tutors, are responsible for imparting the information in the syllabus and hence preparing the students for the exam. If a lecturer does not cover all the material, then the students could be in some trouble, and this makes everyone very unhappy. I have until January 2011 to prepare this course, and it already feels like I’m going to be very squeezed for time!

The Swedish Chef

2010-04-12T01:07:00.000-07:00

Jim Henson was truly a genius of entertainment – bringing us beloved characters from Cookie Monster, to Kermit, to Miss Piggy. One of the ones that always made me laugh was the Swedish Chef: He looked absurd and spoke some vaguely Swedish sounding gibberish. You can see him here in his finest form.

Did you ever wonder why Jim Henson decided that the Chef would be Swedish? He could have been almost any nationality: Turkish, Italian, Chinese, Mongolian,… but would he have been as funny? Somehow I think not. Something is inherently funny about the Swedish language – even if when you are not actually speaking Swedish.

Last week I was in Stockholm for Maria Hermanns’ thesis defense. (More on this later –-- maybe). At dinner the night of her defense, her proud research advisor Hans Hansson said “I am going to tell a joke now, and I apologize that I cannot translate it into English. It is only funny if it is told in a silly sounding language.” When the joke was told (with great gusto) all those who spoke Swedish laughed uproariously.

For the record here is the joke in translation:

There is a fishing vessel – a shrimp boat – off the coast of Sweden, and it has a full load of Swedish shrimp. But somewhere in the huge pile of Swedish shrimp there is a single Norwegian shrimp that had somehow wandered across the border and was caught in Swedish territory.

Q: How do you know, of all these shrimp, which one is the Norwegian shrimp.

A: The Norwegian shrimp is the one jumping up and down screaming “I’m a lobster, I’m a lobster!”.

Like I said. It isn’t very funny in English (And apparently you have to know something about the relationship between Swedes and Norwegians). But in a silly sounding language, apparently it is hysterical – just like the Swedish chef.

Note 1: The reason Hans was reminded about this joke was probably because a few of the people at dinner were eating giant shrimp sandwiches for dinner. (Here, “giant” modifies “sandwich” not “shrimp”). This sandwich consisted of a heap of shrimp about the size of my head on a small slab of bread – the dream sandwich!

Note 2: You might want to try out the “Swedish Cheferizer” which turns any English into Swedish Chef Gibberish.

Awful to Awesome

2010-04-11T02:35:00.000-07:00

Note from the road:

Wandering through the Temple Bar district of Dublin yesterday afternoon, I came across something that was halfway between awesome and awful: a band that specialized with folk covers of your favorite rock tunes -- complete with fiddle as the lead. I managed to find a few videos of them on youtube. Here is a video of them doing Paint it Black. Unfortunately, I could not find a video of their truly grisly version of I will survive. Some of the covers were so awful that they went all the way around the circle to awesome again.

Motivated Students and Motivating Students

2010-04-03T11:57:00.000-07:00

Some of my students are extremely serious, motivated, and smart. I frequently see the same hard-working students at lunch or dinner arguing over some physics problem, or doing some calculation while eating. I’m very impressed with these students, they are a pleasure to teach, and as one might expect, these are exactly the students who have been doing extremely well on their exams.

Even some of the students who arrived at Oxford with an educational deficit (perhaps having gone to a not-so-good high school) have a fair chance of catching up and doing well if they are smart and really work like crazy. Alas, in some cases, if a deficit is too large to begin with, it may be too great to overcome. Nonetheless, I’ve already seen some driven students come here with a philosophy of “succeed or die trying” (or as they said in Sparta "e tan e epitas", with your shield or on it!”). A few of them have pulled off what can only be described as exam miracles.

Then there are a few students of the opposite variety: those who are not working hard enough and are barely scraping by. My initial philosophy upon coming here was to treat them as adults: If they want to waste their education, they are fully entitled to do so. However, it soon became clear that this was not going to be an acceptable policy. To begin with, poorly performing students are considered a bad reflection on a college (and inevitably on the professors that teach them). Secondly, one must remember that much of the funding for education in the UK comes from the government (Oxford was essentially free to UK citizens until just a few years ago –-- now it is absurdly cheap [by US standards], but not free). As such, allowing students to waste their education, and hence UK taxpayer money, is frowned upon. Finally, academic competition between colleges is fierce (as measured by the famous “Norrington Table” – the subject of much discussion around here – I’ll save that for another post). The colleges that perform well by this measure are then able to recruit better students, and then perform even better in future years. At any rate, the upshot is that part of my job is to squeeze the best performance possible out of my students.

A few weeks ago, over a late night beer, I asked a few of my more experienced colleagues how they get their students to work harder. Although answers varied, at least one took a “no-holds-barred” approach: Students worked… or else. Basically this professor viewed it as his job to whip the students into shape, whether or not they appreciated him later for doing so. It turns out that most of his students do actually appreciate him for doing this (although I’m sure there will be a few who don’t like this kind of military approach to matters).

Somewhere along the line most students run into a strict but fair teacher who commands total respect and demands the impossible. In the end, students frequently like and remember fondly these demanding teachers for forcing them to learn. For me, perhaps, it was Mr. Fraction at Twelve Corners Middle School, who was not a math teacher, but an English teacher. He gave me detention every day for a month until I could improve my handwriting to the point where it was readable. I’m not going to say that my handwriting is now particularly legible, but without him, probably even I would not even be able to decipher my own scrawl.

I’m not sure if I have it in me to be one of these taskmasters, I find it difficult to chew out students even when they deserve it. But perhaps slowly, as I get more annoyed with students who are not performing as well as I know they could, I might morph into Mr. Fraction.

Comments encouraged from profs or other teachers who might be reading this…

What it takes to be a Tiger

2010-04-01T12:02:00.000-07:00

Before his recent fall from grace, Tiger Woods was a spokesperson for Accenture, the world’s largest consulting firm. Not a bad spokesperson: dominant in his sport, good looking, and all-American. As long as he kept a squeaky clean image, his contract with Accenture netted him 20 million US $ per year. In Airports all over the western world (JFK, Newark, Heathrow, Stockholm, Amsterdam, to name a few) huge billboard pictures of Tiger were posted with slogans like “We know what it takes to be a tiger.”

When Tiger’s Mistress scandal broke early this winter, Accenture was very fast to sever its ties, but it took them months to replace all of the billboards with Tiger’s photo on them. For the entire winter I walked through airports and watched people snicker at the billboards “We know what it takes to be a tiger – yeah, now the whole world knows too… Har har har.”

Finally, this week I noticed that all the Accenture-Tiger ads in Heathrow have been replaced with an ad that has an elephant on a surfboard. Actually, perhaps Accenture should have done their research into the mating behavior of elephants before choosing this – elephants are pretty far from monogamous.

The inevitable phase shift

2010-03-28T01:58:00.000-07:00

When I first arrived in the UK at Heathrow about 16 months ago, I got on the bus to Oxford and bought myself a round-trip bus ticket. Why? Because one-way is almost as expensive as round-trip and I knew I would be going back to Heathrow soon for any one of my various travels. And so I carried the return ticket in my wallet for a while, and then returned to Heathrow for my first trip. When I came back to Heathrow, I bought another round trip ticket and so forth. So whenever I was in Oxford, I was always carrying around my return bus ticket to Heathrow.

Finally this week in Oxford, I looked in my wallet, and discovered that the inevitable phase shift had happened. I was in Oxford, but I did not have a return bus ticket in my wallet. So from now on, I will be carrying the return ticket when I am on the road, not when I am at home in Oxford.

But what had happened to cause this “phase shift”. Where had my return ticket gone? Had I lost it? No, I was careful about keeping that ticket safe. What had happened was that last week I handed the bus driver in Heathrow a ticket and neither of us noticed that it had already been used. So I actually got three trips out of one round-trip ticket. Well, assuming that I don’t make the same mistake again (either intentionally or unintentionally) I guess from now on, even my bus tickets will indicate that Oxford is home.

My Very Cool (ex-)n-Girlfriend

2010-03-25T08:41:00.001-07:00

Before my ex-girlfriend, there was my ex-ex-girlfriend, and before her was my ex-ex-ex-girlfriend, and so forth.

As luck would have it, Margot, my (ex-)ⁿ-girlfriend, from all the way back in high school, recently got back in touch with me after X years via Facebook (here n is a positive integer and X is a positive real number – both larger than I would like to admit). As it turns out, Margot and her family now live in Portland Oregon, and she has what must be officially the coolest job on the planet –-- she is a vet for the Oregon Zoo. Here is a photo of Margot in action

Being that the March Meeting of the American Physical Society happened to be in Portland this year, I took the opportunity to stop by, catch up, meet her family, and (of course) to see the animals in the zoo! Incidentally, for those of you who don’t already know this about me, I just LOVE zoos. (Maybe it is not so surprising that Margot and I dated each other all those years back.)

Here is a video of Margot in her element, doing dental work on a rather large leopard. And if you like cats you can check out this video too, of the world’s cutest cat – an Ocelot kitten.

Margot’s office in the vet building is a low key affair, but you have to be impressed by the equipment for doing such things as taking x-rays of elephants (Here is a video of exactly that – The elephant is near the end. Margot is at 1:29, I think she is being an anesthesiologist for a bear).

Some of the job is a bit less glamerous - like inspecting turtle poop for signs of parasites (there were none on the day of my visit).

During my visit there were a few animals that needed some vet attention. A relatively elderly zebra was showing signs of congestive heart failure, and they were afraid they would have one zebra less by the end of the day… but in fact it seemed to be recovering slowly. (Although I’m happy for the zebra, it would have been really interesting to watch a zebra autopsy had the zebra actually kicked…. So to speak).

A very cute beaver seemed to have some sort of swollen red eye. Margot poked her head into the lodge where the beaver was hiding but couldn’t get a good enough look at the eye. She decided to return later to try to get a photo of the eye and also to send another vet down to take a look. One of the zookeepers yelled at the beaver “Don’t rub it!”, but I don’t think the beaver listened.

We stopped into a small quarantine building where a female cougar was being kept away from the others. (This cougar may have been acquired from the wild, or from another zoo, I’m not sure). Well, this rather large cat was not in a good mood, and as soon as I walked into the small building it looked at me as if I were her lunch. It stared me down and growled rather alarmingly. Margot scolded it like a mother for being in such a bad mood and threw it a whole (dead) bird for lunch. The cougar did not even blink at the bird, but continued staring at me as if to say “I’m not eating that bird, I want the big guy for lunch.” Grouchy or not, this was a rather beautiful animal.

Perhaps the worst situation of the day was a zookeeper who got some disinfectant in his eye and had to go to the hospital. Despite the assurance of Cosmo Kramer that vets do better work on humans than doctors do, these vets restrict their treatment to animals of the non-human kind.

Most interesting, perhaps, was the work on the elephant’s feet. Apparently elephants in zoos (particularly Asian elephants) frequently develop foot problems, as they are (a) not really meant to be confined to small areas and (b) are not really meant to be walking on such artificial surface. As a result, they tend to develop abscesses and similar trouble. On this particular day the vets were going to try out a new curative on the elephant’s feet. Here is a photo of a vet (Mitch) working on the foot of a female elephant named Sung-Surin, (which I'm told means "Sunshine" in Thai) , but they call her "Shine" for short. (Sorry that the photo is so blurry, I need a better camera). In these photos I am making friends with Shine. She seemed completely unperturbed by my presence. I gather that female elephants are typically better with humans than the male (bull) elephants. In fact, I've been told that as a rule, bull-elephants are considered extremely dangerous and should not ever be in contact with humans. The Oregon zoo has several bulls, and on the particular day that I visited, one of them needed work on his foot. This bull, named Tusko, weighs about twice what Shine weighs -- about 13,500 pounds (over 6000 kilos) -- a rather imposing beast. In this picture (below) you can see him behind some very very thick steel bars that separate him from his human keepers. Apparently on occasion he has gotten upset and rammed his head into the bars, doing some serious damage to the steel, although not actually managing to break out. On this particular day he seemed perfectly willing to do as his keeper asked of him, in return for carrots being thrown into his open mouth. This method of feeding seemed to work pretty well for keeping him calm, and also worked pretty well for giving him his daily medicine: Among other things, an entire bottle of advil which was thrown down his throat and he swallowed in one gulp (perhaps not even noticing that it was not a carrot). To work on repairing his feet, Tusco was convinced (with rewards of carrots) to slip his foot through a very small gate in the giant steel bars, allowing the vets access to his foot while he munched happily on his carrots. You can sort of see in this photo how this works.

Not all of the day was spent doing actual useful vet things. Margot was nice enough to take me around to meet some of the animals just for fun. (As well as meeting her husband and kids, who are very nice human animals.) The penguin in this photo (Moe) is considered their penguin ambassador, as he is pretty good with humans. He still has a tendency to defecate on people though (which I very narrowly avoided). Nonetheless, he didn't seem too upset about being handled. Penguin feathers feel remarkably like fish scales. Perhaps I should not be surprised by this example of convergent evolution but I certainly did not expect them to feel this way.

The armadillo is another very people friendly animal. Apparently this guy is taken around to schools and the like. He is totally harmless and only rolls up into a ball when he is very scared. I think he is a bit scared in this picture, but he eventually unrolled and sniffed around a bit more. Pretty cute little guy. Probably would make a good pet.

Then there are more of the bigger animals. We fed the giraffes from a high window . Advertising has clearly worked on me since now I can't look at a giraffe without thinking of Toys-R-Us. In the picture with Margot you can see the giraffe sticking out his tongue a bit. Actually, the tongue is much longer --- I think about a foot and a half long.

And there are the bears: These black bears were not on display (not sure why) but were living in a cage near the vet building. They seemed pretty happy to have someone come around to feed them all sorts of bear food. "Bear food" in this case consisted of apples, grapes, spinach, lettuce, carrots, broccoli, and generic large animal pellets (similar to the stuff we fed the giraffes). You had to be careful not to stick your fingers through the fence, but the bears seemed to more or less understand that the food was the vegetable-matter and not the people-matter. After they tried all of the stuff that was being offered, it was clear that they really only wanted the spinach and lettuce.

Sadly, I'm out of pictures at this point. There were quite a few animals in the zoo that I saw, but did not photograph: The otters, the beaver, various snakes, some bats (including one in the hospital for a broken arm), some cute rats, lots of monkeys, some boars, bears, lions, hyenas, and other beasts. And alas, perhaps the coolest animal that I saw was not amongst those that I caught on film: The Amur (Siberian) Tigers. Margot seemed particularly fond of them, and, being fully objective, Tigers are among the most amazing animals on earth. Like many of the animals in the zoo, the Tigers did seem to know who she was, and they seemed to like her as well. When we arrived, they were sitting out in their yard sunning themselves (it was perhaps the first sunny day of spring). Despite the fact that they were mid-snooze, when Margot called their names, they were immediately up and alert and they responded by sticking out their tongues and made this face at her.

I gather that this is an expression that indicates affection towards Margot. I was told that if they didn't like someone they would let that be known in no uncertain terms.

To finish off this post, I am including a photo (from the zoo web site) of the two Amur tigers: I think their names are Nicky and Nick (they are brother and sister). Ain't they cute?

Something to Cheer About

2010-03-18T21:36:00.000-07:00

When the nerd-herd arrived in Portland last Sunday, there was a convention already underway at the Oregon convention center -- the Pac-West Open National Cheer and Dance Championships. This consisted mostly of 10-13 year old girls in cheerleading outfits, carrying stuffed pink unicorns or similar, doing cartwheels down the hallway. I’m glad that they thought that the arrival of 6000 Physicists was something to cheer about (and it is about time, I might say). Nonetheless, the combination of physicists and cheerleaders made a bit of an odd mix for a day or two.

Fiona Burnell commented that it would be pretty awesome if some physicist would dress up in a cheerleader outfit, carry a pink unicorn, and go sit in the front row of some of the physics talks and start drilling the speakers with nasty (but valid) physics questions. Everyone agreed that this would be pretty awesome. Sadly, she confessed that she didn’t have the guts to do it herself (and alas, before getting tenure, it would probably not be such a good idea). I don't think I could pull it off either -- I've never been able to do a proper cartwheel. But honestly, someone should do it.

Bible Thumping

2010-03-18T06:29:00.000-07:00

This year, I took forever to decide if I would be going to the APS march meeting in Portland or not. Finally, with only 10 days remaining before the meeting, I bought my plane ticket. With such a late decision, and with 6000 other physicists having booked long ago, I had some trouble finding a decent hotel. Now I’m not one who insists on luxury, but after hearing some horror stories about people bringing home bedbugs, I’ve been a bit more careful about making sure that the places I stay are not complete dives. On the other hand, I am on a pretty tight travel budget so I don’t want to spend too much money (and I’m cheap, just on general principles). But with help of the great Google, I did some research and found a terrific deal. For only 50$ per night, about a third of what most people are paying here, I found myself a first class room – very clean, comfortable, modern, all the amenities included (including a truly great breakfast included every day) and right on the tram-line…

… But there is a catch: My hotel is run by, and inhabited by, evangelicals, who are bent on saving my sinner soul. A large portion of the hotel is converted into a church; many of the rooms of the hotels have been converted into offices of organizations with names like “Christian Council”, and “Serving God Committee”; and the little coffee shop where they serve breakfast is called “Sacred Grounds” (get it?).

On the one hand, the workers here are extremely friendly and helpful. On the other hand, when you go down to breakfast in the morning, the awful Jesus-music is playing on the stereo, and the workers have a tendency to incessantly come over and start conversations with the customers to try to score conversions. I found this all out on the web before I got here, and decided that I needed a fool-proof strategy to keep these people off my sinful back.

So here is my scheme: My hotel room has conveniently been provided with a bible (needless to say). Rather importantly, this is not one of those mini-Gideon versions, but rather a large-print big hefty tome. So, every day when I go down to breakfast, I bring the bible with me and open it up on the table next to me as if I am deep in study. (Being that I have a somewhat rabbinical beard these days, I make a point of opening it up to something near the end [ex, Revelation] so it is clear I’m reading the new part, not the old part). Then I scribble notes on a pad of paper next to the bible. Of course, the notes that I am scribbling are my daily physics thoughts, but to the watchful coffee shop evangelists it looks like I am making notes on the word of God. So far, it has worked. They are convinced I am among the blessed, and not wanting to disturb my study, they have left me alone.

I gotta say, it really is a first class room… the breakfast is great, and 50 bucks is hard to beat.

Notes from the 2010 March meeting

2010-03-17T23:55:00.000-07:00

This year the March meeting of the American physical society is in Portland Oregon – a pretty hip but relatively small city of about half a million people. This week’s influx of 6000 physicists must have made a substantial dent in the median coolness of the city --– particularly within a mile or so of the Oregon convention center, where the nerd-herd is grazing. Among the exciting events of this year’s March meeting is the yearly “physics sing-a-long” and the public lecture on “the physics of superheros” (I kid you not).

Nerd bragging rights aside, there actually has been a lot of pretty awesome top notch physics stuff going on this week. Here’s a partial list of the things I thought were pretty cool so far:

(1) The BEC in a box. JILA has managed to shrink an entire BEC lab down to a small box (well, ok, about the size of a large air conditioner). They set the thing up in the exhibition hall just to show it off.

(2) More and More about topological insulators. The field just keeps getting hotter. There were tons of talks on the topic last year, this year it seems there are even twice as many…

(3) In the topological direction, there have been a bunch of talks about quantum Hall blah blah blah. Closely related was a great talk by Rafi Budakian’s on observation of half quantum vortices in Strontium Ruthenate: Very cool experiment.

(4) Yu-Ju Lin from the experimental group from NIST (The extended family of Bill Phillips) gave a great talk on producing artificial gauge fields for neutral atom BECs

(5) I’m a bit surprised there have not been more talks on AdS/CFT (maybe it is still too early and it is more of an idea than a theory). Nonetheless, the talk given by Allan Adams was really nice – explaining very clearly how gravity can (!potentially!) help us understand phase transitions of complex materials.

(6) No high Tc. I think it is notable how few talks there are on High Tc superconductivity. Maybe the field has finally been put out of our misery.

Border Control and Security

2010-03-14T11:23:00.000-07:00

When I go through border control, the agents behind the desk typically ask a few questions, not because they care, or because it matters what the answer is, but just because they want to see if you trip up at all, which might signal a person who is nervous or making stuff up. I usually respond with minimal answers just to avoid anything that might make the process take longer than usual. A conversation with a passport control agent coming into the US usually goes like this:

Agent: You live in the UK?
Me: Yes
Agent: What do you do there?
Me: I teach
Agent: What do you teach?
Me: Physics
Agent: How long have you lived there?
Me: 15 months
Agent: Are you carrying any tobacco, alcohol, or food?
Me: No
Agent: OK, you may go.

Once, being very tired, going into the Netherlands, at Schiphol airport, I tripped up, and then was pulled out of line for everything but the strip-search. The conversation went something like this

Agent: What brings you to the Netherlands
Me: A conference
Agent: What kind of conference
Me: Physics
Agent: Where is it being held
Me: Ugh… actually I can’t remember

I had flown in very early in the morning, and I was jetlagged, and I had been travelling a lot and simply couldn’t remember where I was supposed to be going.

Agent: You can’t remember?
Me: Ugh… Sorry, I travel a lot. I have it written down somewhere.

At that point they took me out of line, and made me produce all my documentation, and searched my bags just for good measure.

So this week I flew into the US from England and went through passport control at the Minneapolis airport. The conversation took a slightly unusual turn:

Agent: You live in the UK?
Me: Yes
Agent: What do you do there?
Me: I teach
Agent: What do you teach?
Me: Physics
Agent: How long have you lived there?
Me: 15 months
Agent: Are you carrying any tobacco, alcohol, or food?
Me: No
Agent: Are you carrying any macroscopically quantum coherent superfluid Helium?
Me: Uh… (long pause) … well, no… but good question, I suppose.
Agent: OK, you may go.

Well, turns out the passport control agent was a bit of a physics buff. In fact this is not the first time I have heard of this sort of thing happening. My thesis advisor Bert Halperin, tells a story about going through security at Tel-Aviv. My recollection is that the story goes something like this

Agent: You are giving a talk in Isreal?
Bert: Yes
Agent: What is the title of your talk?
Bert: “The composite fermion Fermi liquid”
Agent: Are there gauge field fluctuations
Bert: Ummm.. Yes.
Agent: Did you go beyond mean field theory?
Bert: Yes, we studied it at RPA level.
Agent: Why not Hartree-Fock?
Bert: Well, there are some divergences in the propagator that we haven’t been able to regularize yet.
Agent: And is that really a problem?
Bert: Probably not. In fact there is some recent work suggesting that the divergences don’t matter in physical observables.. but it is not in my talk this time.
Agent: OK, you may go.

Apparently starving physics grad students sometimes work border security as a night job.

Apologies to my Readership

2010-03-14T10:36:00.000-07:00

Yes, I know I have not been keeping up my blog very well. Hilary term, (Jan-March) is pretty busy for me. This year, in addition to the usual tutoring, I had to teach my first lecture course (details here. If you are interested, you can look at the homework assignments). But really, just being busy is not a very good excuse for not blogging. My other excuse is just that I ran out of interesting things to say (to the extent that anything I write here is interesting at all in the first place). I hope to resume writing (and hopefully being interesting) soon.

The alarm on the roof

2010-02-12T04:26:00.000-08:00

A few days ago I walked into my office in the physics department and faintly heard some sort of alarm going off - Beep Beep Beep Beep – like a truck was backing up outside. I ran off to do some tutorials and came back about three hours later, and the alarm was still sounding. “How annoying” I thought, “must be something about the construction outside”.

The next day, I had a short meeting in my office with my grad student, Simon, and the sound was still there. It was still rather quiet, but nonetheless distracting as we tried to focus on physics. I kept looking out the window to see what that damn noise was. Simon suggested that since we couldn’t see the source of the sound outside, maybe it was coming from the roof. Hmm… an alarm on the roof. How strange.

Well, the next day I walked into my office and the alarm was still going. I finally decided that I had to investigate. I opened the window and stuck my head out into the cold to look around. I immediately discovered that in fact the sound was not any louder outside, rather it was much less loud. Scratching my head for a second, I concluded that the noise was coming from inside my office. A few minutes of Sherlock-Holmes-ing, and I found the culprit: My phone was off the hook. I should have been suspicious that no one had called me in a few days. Beep Beep Beep. Now I know what British phones sound like when they are left off the hook.

I am such a moron!

2010-02-04T12:22:00.000-08:00

Last December, before leaving for the holidays, I was struggling to collect financial information to file my UK taxes (the deadline is end of January). Suddenly, as if by divine intervention, I got an email with return address HMRC.gov (That is “Her majesty’s revenue and customs”. ). This email said, in short, “We have sorted out your taxes for you, you will receive a refund”. How nice of them. I even blogged about how nice they were here. Many people had told me that UK taxes were a lot easier than US taxes, so this was perhaps not completely unexpected. I went back to the US for the holidays feeling good about being on the up-and-up with the UK government.

Well, if it seems to be too good to be true, it probably is.

Coming back to the UK, I didn’t think much more about taxes until I started thinking about US taxes (which promise to be a bit of a mess this year). So on Feb 1st, coincidentally one day after UK taxes were due, I set about collecting all my information together. Among other things, I figured the US would probably want to know how much I was taxed by the UK. So I went back and looked at the email sent by HMRC.gov.

And this was where I realized I was duped.

Although the email really does appear to have HMRC.gov as a return address, I was nonetheless became a bit suspicious of some of the links in the email. Exploring around a bit more, and checking out the real HMRC.gov website, I finally came to realize that this email is some complicated phishing scheme where you are supposed to enter your bank info so that they can take all your money.

In the words of the great Homer Simpson...

The good news is that I did not enter any bank information, so they will not get all my money.

The bad news is that I did not file my taxes on time either.

Random Quotes

2010-02-01T02:43:00.000-08:00

Best scientific quote of last month:

“My work was not of interest to anyone else at the time”

- John Cardy, after winning the prestigious Boltzmann medal for the development of boundary conformal field theory, encouraging younger scientists to work on things that they think are interesting, whether or not the rest of the world cares.

Best Excuse of the month for me:

"You are a professor of physics, not of fashion.”

- Christiane Riedinger giving me an excuse to continue to dress like a flood victim.

What I should really listen to:

“You have to get over that”

- Fiona Burnell in regards to my feeling bad about potentially missing a random seminar.

What I should not listen to:

People who tell me that blog postings with random quotes are lame.

Electing the New Pope

2010-01-31T06:48:00.000-08:00

[I wrote this blog posting last spring, but never got around to posting it]

Each of the constituent colleges of Oxford is run by its own governing body, which consists of the “fellows” of the college, meaning essentially the tenured faculty, and a few others (about 40 in total for our college). In fact, in some legal respect which I don’t really understand, the governing body actually owns the college and is completely responsible for everything that happens there. (L’etat c’est nous!) While the head of each college (called the Master, the Principal, the Warden, or whatever, depending on which college you are talking about) is the figure head, and frequently runs the college on a day-to-day basis, the vote of the governing body is the final word on any issue. The phrase “Primus inter pares” (first among equals) is frequently used to refer to the position of the head with respect to the governing body.

These "heads of house” can come from almost any walk of life. Their similarity is that they are all extremely accomplished intellectuals of some sort. Pembroke College Cambridge right now has the ex-head of MI6 (Cue James Bond music).

Dame Fiona Caldicott, the principal of Somerville college Oxford since 1996, is retiring this summer. As such, it is the duty of the governing body of the college to elect a new principal. This process is extremely complicated, with various arcane rules and regulations, which struck me as being similar, perhaps, to electing a new pope. (And Somerville is one of the younger colleges, I’m sure there are some completely insane rules at the 800 year old colleges).

The head of the search committee, Professor Fiona Stafford (yes, many people in this country are named Fiona), did a marvelous job. Some joked that if we couldn’t agree on a candidate we would all agree to draft Professor Stafford. While she had no particular extra power per-se, it was her job to create a process that would satisfy the governing body.

Fiona (Stafford) worked with a headhunting company to target some candidates. I read through the full book of candidate applications (a hundred perhaps) and many of them, on paper, looked spectacular. I am probably forbidden from saying too much about who these people were, but they were pretty impressive.

Eventually the list was narrowed down to about seven frontrunners who were all interviewed. From there, three finalists were selected. Each of these finalists met informally with a fraction of the governing body personally in small groups in the days leading up to the final interview.

To those who do not know the Oxford system, the final interview might seem a bit bizarre, but in fact it is quite similar to the way hiring is done for almost all positions here: The committee (the governing body) sits, in full academic gowns, around a large table. The candidate comes into the room, speaks for twenty minutes, then the committee fires questions at the candidate. The whole thing is over in about an hour. (This is not too dissimilar from the way I was hired).

Once all three finalists were interviewed, the governing body needed to come to a consensus. Like electing a new pope, the governing body was essentially trapped until it came to a conclusion, and white smoke rose from the chimneys. I was psychologically prepared for a very long night. What was surprising to me was how quickly the opinions converged. (Perhaps we are more of one mind than the college of cardinals?). The first thing we did was to go around the table with everyone saying whatever they wanted to say about the candidates. After everyone spoke a straw-poll was taken and one of candidates was already strongly in the lead. A few of the more opinionated members gave impassioned speeches explaining their positions, and a second poll was taken. At the end of the second poll, the majority opinion was extremely close to unanimous. We had decided in advance that we would need a 2/3 majority, but in the end we were essentially without dissent.

And so in just a few hours, the governing body announced that they had tentatively found their candidate. Within a few weeks (after some details were attended to) we announced that the next Principal of Somerville college would be Alice Prochaska.

SCR

2010-01-29T12:23:00.000-08:00

SCR stands for “Senior Common Room”. The usage of this acronym confused me for quite some time. SCR refers not only to the actual room itself, but also to all the people who have access to said room – I.e., the “grown-ups” in our college --- fellows, lecturers, tutors, postdocs, and so forth. Similarly, JCR is “Junior Common Room,” meaning the undergrads, and MCR is “Middle Common Room”, meaning grad students. There are also actual rooms known as the JCR and MCR as well (although they are not as posh as the SCR).

Sometimes the use of this nomenclature for both the room and the group of people gets a bit confusing. The SCR eats at high table. (Note that I did not say “the members of the SCR eat”, but rather “the SCR eats” which makes it sound like the room itself is eating at high table, sounds a bit silly until you get used to it). On normal days, the MCR does not eat at high table, but for formal Hall dinner, the MCR joins the SCR at high table and after dinner both the SCR and the MCR go to the SCR.

Crashing

2010-01-24T16:04:00.000-08:00

The nice thing about the formal hall "High Table" dinners is that they are a relaxed many-hour affair, with several courses, a great deal of wine, all in the company of scholars.

The bad thing about the formal hall "High Table" dinners is that they are a relaxed many-hour affair, with several courses, a great deal of wine, all in the company of scholars.

The truth is that they would be a lot more fun

(a) if I were not so busy these days that several hours seems insanely long for a meal, and...

(b) if I got to choose which scholars I sit next to at dinner (the seating chart is sometimes a very pleasant surprise, and sometimes a cause for groans).

So I thought to myself "there must be an efficient new-yorker way to handle formal high table dinner". And indeed there is.

After the meal is finished in the great hall, the Principal bangs her gavel, all the students stand, and the high table files out to the senior common room, where the after dinner drinks (including nice port), chocolates, coffee, tea, fruit, and whatnot are served. (We do not have snuff like the folks at All Souls though). People linger in the senior common room making conversation , and working on the digestifs -- crucially, there is no seating plan for dessert, so you can talk to whomever you please.

My new york way to handle high table?: Skip the dinner and crash dessert.

I'm not sure that this is actually against the rules, but it is certainly something that no one else seems to do. But why should it be against the rules? I mean, the college has no objection to feeding me dinner with dessert. Why should they object if I decline on the dinner and go straight for the chocolates and port? Despite my insistence that it is all on the up-and-up, I admit that I do not make it all that public that I've become a crasher --- in fact, I tend to hide in the corner of the senior common room far from the principal -- as she is really the only one of sufficient gravitas that I would feel ashamed of myself trying to argue to her that "Well, it may be that it is "just not done" here, but since i dont' see why it is "just not done", I'm just gonna do it anyway".

The number 1

2010-01-24T14:22:00.000-08:00

First let me apologize to my readership for not having posted much recently.

Last december I spoke to one avid reader (yes, there is at least one person who claims to be an avid reader of my blog) who says he keeps reading it in hopes of actually learning something about science, but ends up learning about which airport I'm stuck in.

OK, so here is something cool that is sort of about science. It is known as Benford's law, and roughly it can be summarized by the statement:

Most numbers start with a small digit. About 30% of numbers start with the digit 1. Only about 5% of numbers start with the digit 9.

Huh? Yeah, this one drove me nuts in grad school, because it really depends on what you mean by "Most numbers". But here is a test just to prove the point. Write down a bunch of "random numbers" that you generate by looking at meaningful quantities (and this is important -- the numbers have to mean something, otherwise it doesn't work).

What is your housenumber in your address?
What page is the nearest book open to?
What day of the month is your birthday?
How many dollars (pounds, euros etc) are in your wallet?
How many miles do you drive to work?
How many books do you have in your house?

The chances that the answers to any of these questions start with the digit 1 are extremely high. The chance that any of them start with the digit 9 are very low.

Lets take as an example, day of the month for your birthday. Most months have about 30 days. Choosing a random number from 1 to 30, there are 11 numbers that start with the digit 1, and only one number that begins with the digit 9.

How about a random page in a book. Well if the book has exactly 9 pages, then all digits are equally probable. But if the book has 20 pages, then there is more than a 50% chance that the first digit of a random page begins with the digit 1. (and only 1 out of 20 begin with the digit 9). In fact, only if the book has 9, 99, or 999 will a random page be equally likely to start with the digit 1 as with the digit 9. Since very few books just happen to be exactly this long, 1 is always more likely than 9.

Of course you can cook up questions that do not follow this law: How many hands do you have? How many people does it take to tango? ... but for numbers that are "sufficiently" random, the law is very good.

Now for two final questions:

What year were you born?
What month of the year is it now?

LHC or Bell

2010-01-07T10:18:00.000-08:00

An interesting post discussing the importance of "the old Bell Labs" and comparing the value it gave society in comparison to the LHC. Don't get me wrong, I'm in favor of the LHC. I'm just also in favor of the old Bell Labs as well.

Hat tip to Gerit Quealy for pointing this link out to me.

Web Page

2010-01-06T07:19:00.000-08:00

After a year at Oxford, I finally figured out how to edit my Oxford web page so it looks fairly decent. I'm not sure if I am brave enough to put a link on that page to this blog though. Any thoughts from the peanut gallery?

Harper's Index for 2009

2009-12-26T11:29:00.000-08:00

As 2009 draws to a close, so ends my first year as a resident of the UK. As such, I thought it might be a good time to look back at the year and compile a “Harper’s Index” of interesting things about this year:

Number of Airplane flights: 52
Number of Successful landings: 52
Carbon footprint: Very Bad
Number of transatlantic flights: 12
Number of transatlantic flights that were unpleasant: 12
Number of flights longer that 11 hours: 4
Number of days this year I have consumed more than three cups of coffee: 4

Estimated average number of times I have had tea per day: 2
Estimated average number of times per day I think to myself “I should go buy some better tea”: 2
Estimated number of meals I eat per week which are cooked by Somerville College: 3
Pounds I’ve gained this year: 3
Number of times I’ve eaten haggis: 1
Number of times I’ve eaten kangaroo: 1
Number of times I’ve thought, exotic food is interesting, but really I like plain food better: 2

Number of flights missed due to being late to the airport: 1
Number of holes sawed in my bed while desperately trying to recover my passport in time to make it to the airport: 1

Number of weeks I spent in Oxford this year: 30.5
Number of weeks spent traveling (including vacation): 21.5

Number of boxes moved to UK last January: 75
Number still to be unpacked: 13
Number of boxes of things I probably should have thrown out instead of moving: 13

Number of Giant Spiders in my backyard: 1
Number of Giant Spiders gone AWOL: 1

Number of weeks in the winter spent with Scarlet Fever: 1
Number of tablets of penicillin consumed: 21
Number of months in the summer with a persistent cough: 2
Number of bags of Halls Mentholyptus and Vicks Double Action Consumed: 8

Number of professional talks given: 28
Number of these I recommend for the general public: 1 (See here and here)
Number of talks which were repetitions of the same chalk-talk about Topological Phases of Matter: 12
Number of times the talk was about Topological Lattice Models and Chain-Mail: 6
Number of times I made a joke about the electric slide: 1
Number of times no one laughed at the joke about the electric slide: 1
Papers Posted on arxiv.org: 8
Number of South-Park episodes watched this year: 23
Number of South-Park episodes that were too gross even for me: 3

Number of Blog Postings this year: 98
Number of Blog Postings about Pogo: 3

Despite my physicist instincts, I know that certain important things are not easy to summarize with a single number. So here are a few more interesting opinions from the year:

Biggest advance in feeling like UK is home: I’m no longer self-conscious about the fact that everyone knows I’m a foreigner the minute I open my mouth.

Biggest little kudos to the US Government: Every time I go through passport control coming into the US, they say “welcome home”. I like that.

~~Biggest little kudos to the UK Government: They figure out your taxes for you.~~

Biggest big kudos to the UK Government: Health care works.

Stupidest thing about the UK: Lack of intelligent Plumbing

Biggest bummer: That many of the closest friends I’ve made in Oxford won’t be there next year.

Best travel discovery: At Heathrow there is always someone in duty-free waiting to give you a shot of Baileys. You can even take two or three before they get mad at you.

The blizzard of ’09: Another lesson in thermodynamics.

2009-12-23T05:42:00.000-08:00

When admissions draw to a close, vacation begins. I jumped on a plane to go visit my family in the Washington DC area (Brother Alan, Sister in Law Terry, Niece Seneca and Nephew Milo). My other brother, Rob, also managed to fly in from Chicago.

Well the visit started out fun enough, but after a few hours, dire reports started appearing on all news outlets that the blizzard of the century was about to hit the area. Now DC does not get a lot of snow most years, so like London, when it does snow, they really don’t know what to do with it. In short, it shuts down the entire city.

Usually a snow day is pretty fun. You go out for short periods of time to shovel, or play in the snow. Then you come inside again to warm up. If it only lasts a few days, no big harm done. That is, unless you don’t have heat in your house. Only a few hours before the blizzard was set to hit, the heater in my brother’s house died. It was an old heater, but it certainly picked an inconvenient time to croak. Fortunately, the heater-repair-guy was able to come by before the snow started falling. Unfortunately, he was unable to do anything to help. In short, the whole thing needed to be replaced – which they would not be able to do until after the snow stopped falling.

Thermodynamics lesson: If there is no heat source inside, the temperature of the house will fall to be the same as the temperature outside.

Before the snow started, Rob and I drove out to the local home depot and filled the trunk of Terry’s little Honda civic with a stack of Duraflame logs to burn in the fireplace. We badly underestimated how much wood we would need to burn though. [Although whether we estimated correctly or not, we more or less filled the trunk of the civic. It was dumb not to try to fill it more though].

Well, even with something to burn, the large Maryland suburbia house was not really meant to be heated from the fireplace alone, so most of the house was pretty cold. As the temperature outside dipped to 20F (-7 C), the temperature inside hovered around 50F (10C). [We measured the temperature one room away from the fireplace. In other rooms, it was probably colder]. If we really burnt wood quickly, the temperature would rise only to about 55F (13C).

We all dressed really warmly. Here’s a picture of the three brothers and the Niece and Neph sitting in the room with the fireplace (Alan is on the couch with Seneca, Rob is on the chair, and that is me and Milo on the floor. Note the Oxford sweatshirt on Milo). Surprisingly Seneca and Milo didn’t seem to mind the fact that it was cold at all. They sometimes refused to even wear sweatshirts or socks insisting they weren’t cold. I have no idea what it is about children’s metabolism that makes them generate so much heat, but I was pretty cold. In that picture I was wearing two layers of pants (“trousers” in the UK. “pants” usually means underwear), three layers on top, two layers of socks, and a hat.

In this picture is our savior: Terry… and the Duraflame logs. (Note again the oxford sweatshirt).

We had a lot of fun playing inside. We ran around the house a bit to keep the blood flowing (OK, to be honest, running around the house with Milo and Seneca is on the agenda whether or not there is heat in the house). Rob and I swung Seneca and Milo around in circles until both of us had pulled all the muscles in our backs and then some.

By the middle of the next day, we were running out of wood already. The snow was not falling as hard, so we sent out a team of hearty adventurers to try to find more snow. After clearing the driveway (one of the neighbors had a snowblower) Rob and Alan took out the all-wheel drive Subaru (For those interested, here is the difference between all-wheel and 4-wheel). Not all the roads had been plowed and those that had been plowed were not very clear. Nonetheless, they made it out to a local market that had both more Duraflames and some real wood as well. They stocked up on enough to last a few more days.

This is more or less what it looked like outside at the time. The total snowfall was about 21 inches. Yeah, I know, if you are from Montreal or any other really snowy place, this is nothing. But DC is a very warm climate. That was more snow that DC usually gets in any entire year – all in one day.

Of course, the snow was pretty fun to play in too for some of us.

The next evening Rob had to go back to Chicago, and I was supposed to fly to Rochester to visit my parents. The main roads were clear by then, so it was no problem getting to BWI airport. But the airport was a zoo. There were people I talked to in the airport who had literally been there for three consecutive days trying to get home for the holidays. Many of them were military on holiday leave who had set up a virtual camp in the airport. Our planes were somewhat delayed, but at least left that day.

The next day the repair people started work on the heater. By that time, Alan and Terry had grown exhausted of living in the cold and the family drove to Terry’s Mom’s house to stay there for a while (it is not far away – if the roads are clear). With luck, in a day or two more, they can move home again!

Admissions

2009-12-16T13:38:00.000-08:00

The undergraduate admissions process here is interesting. To begin with, the faculty does the admissions directly, rather than some centralized admissions office. If you apply to Oxford to “Read” physics, you are interviewed by the Physics faculty who would be teaching you, were you to be admitted. This gives the faculty a chance to choose their own mistakes.

In the UK it is a strict rule that you can only apply to Oxford OR Cambridge, not both. Given this, Oxford gets a bit over 1000 applicants for roughly 180 Physics places. Actually, that is pretty good odds for the students, as in some other subjects the ratio is much worse. Incidentally, admission here is like Early Decision in the states where it is understood that you will attend if you are accepted. A few alternates are chosen in case someone bails out, but this is pretty rare.

The students send the usual transcripts, recommendation letter (just one from their school), and short essay. They then are asked to “sit” a pretty hard entrance exam. The exam was instituted in a truly organized way only a few years ago, so the clever prep-schools are just beginning to be able to train their students for the exam. Up to this point, however, the entrance exam has been the best indicator of future success at Oxford. So the exam is now taken pretty seriously. (Perhaps once Stanley Kaplan and Princeton Review start giving courses to help people game the system on this exam, its validity as an indicator will drop).

The students who perform above a cutoff on the exam are “summoned” for interviews (this does not involve flue-powder). Those that do not make the cutoff are “de-summoned”. In a few cases, a student may be “rescued” from below the cutoff for one reason or another – for example, if their school does not even teach physics and they had to learn everything on their own. If you score way up near the top on the entrance exam (top 50 or so) you are virtually guaranteed a place unless you do so badly on the interview that you are suspected of cheating on your exam. In all, roughly half the students are summoned for interviews. So that means roughly 2.5 students will be interviewed for one place.

When the students are summoned for interviews, they are asked to come to Oxford for several days – during which they stay in the dorms and mostly seem to roam around and get nervous about their interviews. During that time they are given at least three interviews. Interviews are typically done in teams of at least two interviewers to one student. Whichever college is the student’s first choice college interviews the student twice (two teams of two interviewers), and their second choice college interviews them once. Sometimes a student declares a first choice college, but that college has too many applicants so the student is assigned a new first choice college. If you are a phys/phil (physics and philosophy) candidate you are interviewed these three times by physicists and then at least twice by philosophers as well. Some of the overseas candidates are interviewed by telephone, and one has to assume that these interviews have bigger error bars. We have a fair number of overseas applicants, but I'm surprised we do not have more from the US. (Even including travel costs, Oxford is still less expensive than most elite US colleges I think).

Each interview results in a grade from 1 to 10. All of the interview scores are uploaded to a central database, which all the faculty can examine. All of the student's information (including grades, tests, interviews, etc etc) are posted and also amalgamated into one overall score and everything is listed in a systematic and organized way. Each college is listed along with how many slots they need to fill (usually 6 or 7 per each of about 30 colleges) and all the data about all the students they interviewed is listed too. (Hogwarts college is also listed in this file – I’m not making this up, I think it represents stray unaffiliated interviews, unaffiliated students, or something like that). Once all this data is posted, then the drafting and horse-trading begins.

If a student has an amalgamated score in the top 100, they are essentially assured a place – and almost always in the college they designate as their first choice. Even if their first choice college does not want to take a high scoring student for some reason, these students will be snapped up by the second choice college or by other colleges who did not get enough good applicants. Almost all of the arguing and finagling is to allocate the last 80 places in the class. Essentially we have to pick 80 students of roughly the next 200 highest scorers at this point (and defend the decisions).

If a student scores worse than 300th, they are almost certain to be rejected. In a few rare cases, a student will mathematically land worse than 300th, but will be rescued because of extenuating circumstances – like if they come from a particularly poor school, or difficult family situation, and they had to work like crazy even just to get this far (which is often a good indicator that they will still be able to do well by continuing to work like crazy). In these cases, the colleges that decide to take students who score lower, must stand up and make the case of why they are not taking better scoring students… and sometimes they are even requested to report years later on the progress of such rescued students to reaffirm that this philosophy of breaking the rules is actually a good one.

This year I won’t be taking part in the horse trading meeting (the other physics fellow from Somerville is in charge this year… I’ll get my chance next year). The meeting sounds a bit like the NFL draft, where everything happens in real time and every decision is publicly announced with great fanfare – and objections may be raised at any time and the drafting team must defend its decision. The college representatives (the faculty) have several objectives --- both to draft a good "team" for their own college, but also to make sure that any student they think is worthy is taken by some college, even if their own particular college does not have a place for them.

This year I think Somerville will do very well in the draft. While, not having any super-super-stars, a number of strong candidates listed Somerville as their first choices – and we will be very happy to have them. We need to recruit about 6 students and we have most of them nailed down before the draft starts. I’m optimistic that this will be a reasonably good class!

Why The Principal Knows Everything

2009-12-12T12:56:00.000-08:00

I’m always the last to figure things out. But the clues were all around me:

Fact 1: Dame Fiona, the principal of Somerville college Oxford, seems to know everything that goes on within college. I always attributed this to her particularly acute perception –- on account of the fact that she was trained as a Psychiatrist.

Fact 2: Dame Fiona’s cat, Pogo, freely wanders the entire college, frequently unobserved. Yesterday he was sitting amongst the high school students as they waited for their admissions interviews.

Fact 3: I have never seen Fiona and Pogo in the same place at the same time... except in this very famous painting of the two of them that hangs in the great Hall.

Yes, now it is obvious: Pogo is Fiona’s alter-ego. With appropriate credit to J. K. Rowling, Fiona is obviously an Animagus, akin to one of my favorite characters Minerva McGonagall who also turns into a cat, and who also is the head of a house… coincindence? Hmmmm...

~~The painting is painted by Susannah Fiennes, who is the cousin of Ralph Fiennes, who plays Lord Voldemort in the films. Another coincidence? Hmmm...~~ See correction in comments section.

[Photo Credit: Christiane Riedinger].

What is physics about? And what is college about?

2009-12-07T07:18:00.000-08:00

What is physics? I mean, what is it all about? What is the big uber-goal that we are all working for? What are the really important directions of research these days?

If you ask a physicist any one of these questions, you will inevitably get the same kind answer. Every physicist will tell you “What I work on is really important and interesting. What I do is what physics is about.” (Here “I” means whoever you ask, not “Steve Simon”). And I think most physicists passionately believe this. If they didn’t believe it, they probably would have (or should have) switched fields long ago to work on what they think is truly important.

Just for example, if you ask “is physics an experimental science?” chances are if you ask an experimentalist they will say “Of course.” If you ask a string theorist, they might say “Er… not necessarily.”

I think this diversity of views of physics is a good thing. The only thing, we really all share, is the underlying belief (perhaps faith) that the world around us can somehow be understood. However, sometimes diversity of views causes some real problems. Obviously dividing up the limited funding pie is a seriously sore point for many people.

“Why should *THEY* get so much funding when what *I* do is so much more important and interesting.”

“Do we really need to hire another physicist who does X when Y is so exciting these days.”

Or conversely

“That stuff isn’t even physics! Why would we pay to have *that* in our department”

Here at Oxford this diversity of opinion rears its head in some interesting places. One point of conflict (that seems less prevalent in the states) is over the undergraduate syllabus. Here in the UK (indeed in much of the non-US world) the undergraduate syllabus is extremely constrained. This is quite a change from my undergraduate experience (Brown University) – which required only obtaining 28 passing grades for graduation, and had no further detailed requirements: every choice of what to study was left completely to the student. In Oxford, the students follow a very rigid path. [ There are obvious advantages to each system – to be discussed another time.]

So it seems that over here someone is always saying what a travesty it is that a student with an Oxford physics degree might graduate without any exposure to X, Y or Z. Typically the person stating this is someone who has particular interest in X, Y, or Z. Further, getting X,Y,Z into the curriculum boosts the status of those researchers who study X,Y, and Z in the department – as there will always be a need, thereafter, for people to teach the subject.

But do undergrads really need X,Y,Z? How much does it even matter what they learn? Is a college degree about learning a particular topic, or about learning how to learn – about stretching you brain on anything really hard.

I think both answers are valid, although I do have a bias. If you want to guess my bias… here is a hint: For the record, here is a list of courses that I did NOT have as an undergrad:

Statistical Mechanics
Thermodynamics
Solid State Physics
Electricity and Magnetism
(beyond the level of Purcell’s introductory book)
General Relativity
Astrophysics or Cosmology
Advanced/Relativistic Quantum Mechanics
Field Theory
Fluid Dynamics
Optics
Advanced Laboratory

[yes, I did realize upon graduation that I was woefully unprepared for grad school, so I finagled to take some extra courses for a year to make up some of the difference].

His Dark Environment

2009-12-01T00:36:00.000-08:00

The winter here gets very dark. This is not surprising considering how far north we are. Despite our relatively mild winters (courtesy of the Gulf Stream) we are far north of even Quebec City.

The shortest day of the year, the winter solstice, December 21st --- is a date celebrated in one way or another by most cultures on earth. On this day, London only gets 7 hours and 50 minutes of sunlight – substantially less than New York which gets 9 hours 15 minutes. On the other hand, if you happen to live in Oslo, you only get 5 hours 53, and if you live in Svalbard you won’t see the sun at all from the end of October til mid February.

However, surprisingly, the solistice is not the day when the sun sets the earliest, or rises the latest. In New York, the earliest sunset is actually December 8th and the latest sunrise is January 4th. As you get further north, these two dates get closer together: Here in London, the earliest sunset is December 12th and the latest sunrise is December 29th.

At one point in graduate school I remember pondering the geometry of why this happens --- which has to do mainly with the angle of the earth with respect to its orbital plane (if I remember correctly). I think it was my friend Dave Morin who managed to figure it out --- not surprisingly he just finished writing a classical mechanics textbook with a ton of really hard problems in it.

Where is Shelob?

2009-11-28T10:37:00.000-08:00

Earlier in the year I blogged about S.O.U.S. (Spiders of Unusual Size). One of these little beasts had made her home in my backyard and I decided to give her a rather wide berth. Particularly since I was away so much of the summer, it seemed reasonable that she could have reign of the backyard while I was gone. Well, returning home for the beginning of noughth week, I discovered that she had disappeared – vanished without a trace. I joked that we had made a deal, I bought her plane tickets to florida for the winter, and in return she spun a web with the words “Some Physicist” (*). However, what I really suspected was that she had just come to the end of her life cycle (which for some spiders is not very long). Particularly in cold climates, spider life cycle tends to be yearly and it I figured it was a good bet that Shelob had croaked.

Alas, I fear this may not be the case. Over lunch with Dame Carol Jordan, the discussion randomly turned to the S.O.U.S. “Oh, yes”. She said. “I think that type of garden spider hibernates for the winter and comes back out in the spring… impressive little things aren’t they?”.

I wish I hadn’t asked. Remind me to not go out in my backyard for the next year or two.

(*) Joke credit goes to Nuntiya Kakanantadilok

Live Long and Prosper

2009-11-28T07:34:00.000-08:00

Us nerds know how to party.

My friend Christiane decided that for her birthday she would throw herself a star-trek themed party. You might expect this to be a complete nerd-fest (ok, maybe it was) but it was really fun!

Here is a picture of Christiane dressed as 7 of 9.

And here is a picture of the actual 7 of 9.. not bad huh?

Then we had Christiane's boyfriend Luke dressed as Riker (left) and Dina dressed as Betazoid Deanna Troi (right). Dr. Justin is in the middle there appropriately dressed as a medical officer. Compare to the original Riker and Troi:

Random vulcan star trek officers included Christiane's mother and sister:

Note the full life-sized picture of 7of9 in the background. Also note the flag of the united federation of planets. Way in the upper left of that photo you can also see part of some random star-trek weapon hanging on the wall. Probably Klingon.

And one photo of the general crowd. Darcy in the foreground has some serious vulcan ears... or maybe they are elf ears she is just trying out in advance of the next party --- I'm hoping for a lord of the rings themed party coming up soon.

Dancing went on til 2am. Not a bad party.

Too Cliché: The great discovery of Ogg.

2009-11-11T11:09:00.000-08:00

.. and while I am on the subject of thermodynamics..

Once upon a time there was a very clever caveman named Ogg. Ogg made the remarkable discovery that hot plus cold equals warm. Although this knowledge has been passed from generation to generation, somehow, the memo did not reach British plumbers.

Of all the complaints Americans have about the UK, one of the most cliché, and yet most valid, is the complete stupidity of the plumbing. The Brits absolutely insist on having two taps for water: one that delivers hot water and one that delivers cold – and never the twain shall meet. So when you wash your hands, you have the choice of water that is scalding, or water that is freezing. Americans inevitably turn them both on then rapidly pass their hands under each one in quick succession to create the illusion of warm water while trying not to burn themselves. (Kirill Shtengel likes to joke that the British shower has a hot shower head and a cold shower head and you are supposed to jump back and forth between the two).

I mean, how hard is it really to plumb the two taps together so you can make warm water from hot and cold?

Yes, I understand the intention is that you are supposed to fill a basin with the combination of the two, and then you are supposed to wash your hands in the basin. But, for example, in a public restroom, you usually don’t have a plug for the basin, and even if you did, you wouldn’t want to actually touch water that had touched the basin anyway.

In my house, there are three sets of faucets. The kitchen sink, the bathroom sink, and the tub. Of the three, the only one which is 20th century in its plumbing is the tub – which conveniently is the only one of the three where it really doesn’t matter.

Thermodynamics

2009-11-08T07:15:00.000-08:00

The weather is turning chilly here in Oxford. Like clockwork, the heat and hot water failed in my apartment last week. I became painfully aware of an important principle of thermodynamics: When it is cold out, if you don’t have heat, you get pretty cold too.

Anyway, after a few days of poking at the boiler, I narrowed the problem down to a problem with the pilot light. I tried relighting it, but even after a dozen attempts or so (and a few more cold nights), still no luck.

My last resort before calling a professional was to consult the oracle of google. Typing in “flamingo 40 boiler pilot light problem” came up with a number of discussions of exactly this issue. It turns out there is some “Overheat Themostat Reset Button” hidden in the device. If it gets tripped you have to reset it before the pilot will light again.

As a physicist I've always been a big fan of thermodynamics. Reading about thermo makes me generally happy. But I think watching the heat come back on after multiple cold nights made me even happier than reading Enrico Fermi's great lectures on thermo.

2009 Concert Tour

2009-11-02T09:02:00.000-08:00

Many rock bands go on tour and give the same show night after night. Typically they sell t-shirts listing all of the locations and dates where they performed. This is what I feel like with the colloquium talk I’ve been giving this year. I constructed the talk for KITP Santa Barbara last spring (See here. On the web here) and it went over so well that I decided to do a few repeats. Soon, word got around that it is a pretty fun talk and all of a sudden, I’m doing repeat performances all over.

Here is the list just for October and November:

Friday October 2nd NUIM Maynooth Ireland
Thursday October 8th Univeristy of Warwick, UK
Friday October 23rd, University of Exeter, UK
Friday October 30th, University of Saint Andrews, Scotland
Friday November 6th, University of Leiden, Netherlands
Wednesday November 18th, Royal Holloway University, London ,UK
Wednesday November 25th,University of Utrecht, Netherlands

By the end of the term, I suspect I will be rather sick of this talk. Maybe I’ll sell t-shirts* (or veggie burritos).

*Credit: the idea of making a concert t-shirt is from Susanne Viefers.

Andy, Andrew, and Saint Andrews

2009-11-01T07:13:00.000-08:00

My two friends Andy McKenzie and Andrew Green used to be the only two people I knew in the Physics department at the University of Saint Andrews. I postulated that your name had to be Andrew to work there. This postulate was eventually disproven when they hired Chris Hooley.

This week I visited Saint Andrews for only a day, and had a terrific time while there. (Sadly, Chris, who is endlessly entertaining (See here), was not around during my visit).

When I arrived in Saint Andrews, I met up with Andrew Green for a pint of Deuchers (which is a very fine Scottish beer) and a sushi dinner. Then we went to a bar where there was a jazz jam session. Andrew is a very accomplished jazz trombonist, and over the years (I hesitate to say how many years we have been friends now) we have frequently talked about our common interest in jazz. I haven’t played in a quite a few years; and I believe somewhere along the line Andrew also fell out of practice for a bit, but unlike me, he did manage to start up again (with some effort) and now plays quite well. I was really looking forward to hearing him play for the first time. He even suggested I bring my horn, but I couldn’t bear to play in public without at least a few months of woodshedding to get the chops back in order … maybe this will be a project for the future. Anyway, the Saint Andrews jam session seemed like a very nice group of musicians. People subbed in and out very generously, and nicely accepted players of all levels. Many of the players were pretty good, and some were extremely good. One or two were less than good (to put it generously), but no one seemed to mind much. Rather than making me cringe, it made me feel that I should have jumped in and played --- chops or no. The bar was crowded and most people were only half listening anyway, so the occasional painful moments passed without notice.

Andrew did a super “Stolen Moments” (To quote him, “That tune works really well on trombone”). His playing was extremely clean (Even some very good trombonists fall short on this score), and his improvisation on this tune was very smooth. I was suitably impressed. The rhythm section was led by an ancient, and rather portly, pianist who was great. The drums and bass were also quite good. The guitarist -- a retired GP who looked like he was about to keel over at any moment -- also managed to hold his own. Andrew opted out of most of the tunes of the evening to give others a chance to play.

I’m sure the jam session would have gone late into the evening, but for the fact that by decree of the neighbors music must stop in that bar at 11:30. Perhaps this was just as well, as I had had a long day already – having been awake way too early to give all my tutorials in the morning at Oxford before heading to Heathrow.

**

The next morning, after my colloquium (which went very well), I chatted physics with three very interesting sets of people for the rest of the day:

First, Andrew Green – I took the opportunity to tell him all about this topic which I am pretty excited about these days. He gave last week’s condensed matter theory forum talk at Oxford (which was excellent), so I had already heard recently about his work.

Second, Ulf Leonhardt: I had never met him before, but he seems to be doing some really interesting stuff. Among other things, he was one of the guys who developed the recently publicized idea of the invisibility cloak (yes,that is for real).

Third, Andy McKenzie and his research group. Andy is a terrific experimentalist who studies many interesting exotic materials systems – including Sr2RuO4 which is one of the materials that “topological” people like me are most interested in these days.

I wish I had had more time to chat with everyone – but soon enough it was time to rush back to the airport. Maybe I’ll go back up there for another visit soon.

PS: This is my 100th blog posting!

I am going to gain so much weight

2009-10-30T15:47:00.001-07:00

A few night’s back, high-table dinner was a terrific leg of lamb. Fist course was a shrimp salad, and dessert was a chocolate and beet root cake (sounds strange but it was actually wonderful). As if that was not enough to keep me fed, the cake was served with clotted cream – which, when combined with the cake, is delicious! Once I turn that corner and start eating clotted cream… it is only a matter of time.

The Squalid State

2009-10-29T07:01:00.000-07:00

This posting is not about the status of my flat (no comment as to whether that would be an appropriate title).

“Squalid State” is the derogatory term used to refer to the field of “Solid State” physics by other physicists, and sometimes with good reason. The field is full of people studying what appears to be the boring minutia of particular physical materials: why this impurity increases specific heat and that impurity reduces it – and so forth. This entire field of study looked so horrid to me when I was an undergrad that I absolutely refused to even consider taking a solid state physics course.

It is rather ironic then that I became a solid state physicist – or, more properly, a “condensed matter” physicist who spends a lot of time thinking about solid state. So why am I now excited about the field whereas once-upon-a-time I thought the whole endeavor was dismal? Well, I now realize that some of the most exciting physics out there is in condensed matter systems, that the diversity of condensed matter is unrivaled in any other field, that many of the deepest ideas can be tested and explored best in condensed matter systems, not to mention the importance of potential applications in this field. Unfortunately, these exciting features are extremely well hidden in introductory solid state physics courses --- almost as if by design.

This year the physics department at Oxford has decided to revamp its third year syllabus. Everyone agreed that the previous third year undergrad program was not working and that we would all benefit from trying something new. I volunteered to develop the solid state physics course for a maiden voyage in 2010-2011, when I will teach this to 180 student, more or less. I view myself as the ideal person to teach this precisely because I thought it was so boring. My job will be to make it non-awful, to somehow bring out the exciting part of the field rather than the dismal part.

However, to some extent I am trying to do this with one hand tied behind my back. The IOP (british Institute of Physics) mandates that certain topics MUST be taught in an undergraduate syllabus. Further, my colleagues will not stand for me eliminating certain other topics. Finally, the total number of lectures cannot exceed 22. Despite these rather serious boundary conditions, I still think that I can put together a very nice course – and this is what I’ve been working on for the past few weeks, and will continue to work on for the next year.

So, to all the physicists reading this: Did anyone have a good solid state physics course? If so, why did you like it, who taught it, what was covered, what book did you use?

Noughth Week

2009-10-08T12:41:00.000-07:00

Last week ended my summer of constant travel and I returned to Oxford for “noughth week”. To understand this nomenclature one needs two pieces of information:

First, the weeks of the term are numbered 1-8 (Yes, the terms are only 8 weeks long, making them officially insanely short). No one at Oxford ever uses real calendar dates – instead they will just say “our next meeting is Monday of 5th week” or something of that sort. If you make the mistake of asking “what are you doing on November 3rd?” a person will likely ask “which week is that?” This system does actually make some sense because you can have meetings that occur perpetually on, say, Friday of 1st week (as the Physics Theory Sub-Department meeting does) independent of the term or the year, which is then somehow immune from the fickle fluctuations of the Gregorian calendar.

The second piece of crucial information is that “noughth” means “zeroth” (as in “all for nought”).

With those key facts it should be clear that “noughth week” is the week before classes actually start at Oxford. During this week in Michaelmas term (fall term) the new first year undergraduate students (“Freshers” over here rather than “Freshmen” or “Frosh”) arrive, and the 2nd-4th year students return, hopefully more rested than I am, from their summer breaks.

Over the course of noughth week, things accelerate extremely quickly. Since the terms are so insanely short, once you are in-term, everything is a sprint. The students move in by about Wednesday of noughth week, and by Friday all organizational meetings are done so that by Monday of 1st week, the term is going full speed.

Perhaps the most important event of the week is meeting the new Freshers, which mostly happens at an event known as Fresher’s Dinner. This is a formal dinner in the Great Hall where, very unusually, the Faculty sits at the tables with the students (usually the faculty sits at High Table). As one of my colleagues warned me “Depending your students, this dinner can either be really fun and interesting, or a socially difficult Marathon of trying to think up small talk”. Fortunately, my incoming students this year were a lot of fun to chat with.

Oh, and the Somerville chef decided to serve Kangaroo meat (there was also a vegetarian option). And of course there is a lot of wine at dinner. The drinking age is 18 in this country – so this is to be expected for a formal dinner.

This year’s crop of new Physics students at Somerville consists of four boys and two girls, plus one Physics-Philosophy hybrid, also a girl, making the gender mix pretty close to 50/50. While there are a few girls in the upper classes, it still is a bit unusual to have such a high fraction of girls in the Physics group. (My second year students, for example, are six boys and no girls). Perhaps this is just gender balance finally coming to physics, or perhaps it is an anomaly (or more likely a bit of both).

At any rate, now that the term is starting, my life is about to become completely insane for the next eight weeks. Forgive me if I am a bit sparse on the blog postings.

Oh, and with history repeating itself, at the beginning of noughth week, I had the flu.

Bad Bets... and the Nobel Prize

2009-10-08T12:25:00.000-07:00

My grandfather was a bookie – a guy who professionally handles bets. Although a good bookie never needs to risk much of his own money (since his bets are well balanced with just a bit of a margin for profit) most bookies do know what a good bet is and what a bad bet is.

Apparently I have no idea what a good bet is – even when I know a topic extremely well. My predictions for the Nobel Prize in Physics this year were way off*. Even listing everyone I could think of who was in the running, I didn’t even get close. The winners were not even on my radar screen. This is particularly embarrassing since two of the three winners were old Bell Labs guys and I certainly knew very well of their work, and of its importance [ although I never met either one of them since even the younger of the two retired from Bell a decade before I ever arrived ].

The two guys at Bell, Smith and Boyle, are credited with inventing the CCD (Charge Coupled Device). That is the little semiconductor gizmo that turns an optical picture into a stream of electrons which then can be turned into a digital computer file. There’s a CCD in every digital camera. The other guy, Kao, who shared the Nobel with them, developed the fiber optic, which comprises the famous “series of tubes” which carry information through the internet. Bits of information are turned into photons that run down glass fibers called optical fibers.

The prize this year was perhaps an unusual one – it is clearly technology rather than physics, but it is important technology. There has been some grousing around the internet (for example, here) that this prize was not deserving because it is just engineering. (Here I’m repeating here a comment that I posted on Doug’s blog here) The key question is what the Nobel prize should be about --- what the Nobel prize "brand" should mean. There are certainly plenty of important technology/physics advances that could potentially be recognized --- and the original intent of Nobel’s will certainly gave this latitude. It also said that the discovery should be made within the previous year --- a requirement which has been duly ignored ever since ---- which shows mainly that the Nobel committee can do whatever they want to do to promote the "brand" as they see fit. However, by far, MOST of the prizes have been for "fundamental" physics advances, and not for technology advances, which sets a precedent for what the committee thinks it is supposed to be about and this prize does not look so consistent with that interpretation. (The integrated circuit prize was another recent prize for technology --- although I think that this prize was perhaps more agreed upon as being a universal game changer that needed to be recognized).

*I did make the right prediction for the Nobel Prize in Physiology and Medicine, but almost everyone seemed to know that one in advance.

** Added: Obama's Nobel: Yes, I was pretty surprised by this one too. Many people say he hasn't earned it yet, but if you read the explanation given by the committee, it makes sense. I like it.

The return of Delsey?

2009-09-29T12:15:00.001-07:00

The online web BMI lost luggage system now reads "Item Located, pending confirmation". Should I get my hopes up?

Wednesday Sept 30: BMI is expecting my luggage to arrive at Heathrow from Paris today. I'm supposed to check back later today. It has only been twelve days that I've been living without my travel iron and my Snoopy t-shirt, I suppose a few more hours won't hurt.

Thursday Oct 1: Well, they didn't get it yesterday afternoon, and now since it is officially more than 12 days the BMI baggage tracing system is no longer tracking it and now it becomes responsibility of the central BMI baggage service -- who does not have a web site and refuses to answer their phone. ARGGG!

Friday Oct 2: Now I'm told that Air France has delivered the bag to my home in Oxford. This is rather surprising, as there is no one at my home to accept it -- and the mail slot is certainly too small.

Friday Afternoon Oct 2: I'm starting to believe that I might actually get Delsey back. Air France claims to have given the bag to a courier company who is tasked in getting it back to me once I return to the UK. Perhaps this story might have a happy ending after all.

Sunday 12:15 PM Oct 4. Oxford. I have been reunited with Delsey. It only took 16 days.

Nobel-Bets 2009

2009-09-27T04:47:00.000-07:00

Well, it is that time of year again – the time when some really smart people start losing sleep worrying about whether they will get the Nobel prize. For the literature prize the official betting odds are listed here. The favorite is Amos Oz, but Bob Dylan is a 25:1 long shot on this list.

For the physics prize, each year, I try to make a few predictions for who will win. Last year’s incorrect prediction is posted on my blog here (Egad, that means I’ve been blogging for a whole year now!). This year I decided to do a bit more homework before making my prediction. While neutrino mass (my prediction from last year) still seems to me to be pretty important, after scanning the web, it seems to me that almost no one thinks that this is a contender. I suppose, like for the Oscars, the opinions of the masses may be important, so this year I am switching my bet to

Yakir Aharanov and Michael Berry

These two studied what are known as “Geometric Phases” in physics. (For the experts, yes, you can think of the Aharanov Bohm phase as being geometric, although you have to expand your picture of geometry a bit). Perhaps the simplest example of an interesting geometric phase is the strange quantum mechanical fact that when you rotate an electron around in a circle by 360 degrees you do not get back to where you started.

The Reuter’s web site gives Aharanov and Berry support from 19% of those polled. (Several other blogs here and here and here and here agree that this is a good bet).

However, according to the Reuters shortlist, the frontrunners for the prize should be recognized for discovering forms of carbon. Reuters proposes Geim and Novoselov (22%) for the discovery of graphene (carbon sheets) and Ijima (14%) narrowly behind for the discovery of nanotubes (carbon sheets rolled up into a tube). Not that I am opposed to carbon but…

I will remind everyone that Buckyballs, yet another form of Carbon, already won the Nobel prize recently – but in chemistry, not physics. I will also remind everyone that not every molecule made of carbon deserves an immediate Nobel prize. I know that the Carbonists have been lobbying hard, and admittedly both nanotubes and graphene are pretty cool. But I don’t think they are so overwhelmingly cool that they need a Nobel prize just yet. And if the lessons of Buckyballs are anything to learn from, we should expect that the hype will far outweigh the actual usefulness of, or interest in, the stuff in the long run.

A few other people who appear to be on many of the shortlists are Cirac and Zoller (too early in my mind, but maybe sometime soon), and Peter Higgs (not until the elusive Higgs boson is actually discovered). Daniel Kleppner is another person frequently mentioned. Some people have proposed John Pendry for metamaterials and the famous cloaking device (while cool, i think this is far from Nobel material). Also the discovery of the top quark is still waiting for a prize and of course my prior mention of neutrino mass I still think is deserving. I'd also like people to think about some of the dark-horse candidates: Thouless, Halperin (my PhD advisor, I'm biased), and Haldane, are some of the people from my community who could potentially be in the running.

Anyway, we will find out within a few days now.

In other Nobel prediction news:

In Physiology and Medicine, one of the names very high on the Reuters list is Seiji Ogawa. He’s an old Bell labs guy, who invented functional MRI (fMRI) - the MRI machines that can see brain activity. For a brief moment, I think he was listed as being a consultant and I was listed as his boss at Bell labs, although in truth by that time he was listed on our roster for publicity only... and he never showed up any more – I suspect he would not recognize me if I bit him (and I have no intention of biting him, whether or not he wins the prize).

Other contenders in Physiology: Telomerase seems to be the front-runner, with stem-cells another good bet.

The Great Bach-Mendelssohn Smackdown

2009-09-27T03:08:00.000-07:00

Since this year marks the 200th birthday of the composer Felix Mendelssohn, it seems only fitting to give him a chance to compete head to head with the great master – the heavyweight world champion, Johann Sebastian Bach.

The concert last Thursday evening, part of a festival called “pipeworks”, juxtaposed Mendelssohn organ and choral pieces with Bach organ and choral pieces. One is supposed to hear how heavily Bach influenced Mendelssohn, but I like to think of it as a competition where we have given the challenger a chance to win the championship belt.

The ~~competition~~ concert started with a Bach organ Prelude and Fugue (C major, BWV 545). While this is a great piece, the delivery left something to be desired. The pipes of the organ that were used in this performance sounded a bit too much like a Nintendo Game-Boy. So while this should have been spectacular, instead it left just enough room for the Mendelssohn fans to think that Bach could be defeated that evening. But before getting too cocky, these fans were smacked down by Bach’s amazing Double Chorus "Komm, Jesu komm” (BWV 229) which was excellently performed and set an extremely high bar for the challenger to try to match. (Here's a pretty good recording from the 90's).

The next section of the evening was perhaps the most interesting: six short organ pieces by Bach (BWV 599,606,614,618,621,630) from the Orgelbuchlein alternately interspersed with the six "Spruche” (Op 79) by Mendelssohn for choir. While the Mendelssohn choir pieces were also excellent, these organ pieces are masterworks and are more varied and modern than you might expect from Bach. The organist did not repeat the mistakes of the Prelude and Fugue and generally gave an excellent showing. The final BWV 630 was in classic Bach style and was perfectly performed. (Here is one you tube and another of the piece)

At the two thirds mark, Bach still held a strong lead. But the closing innings would belong to Mendelssohn.

The final part of the program gave the challenger his chance to shine: A performance of his Double Chorus Psalm 2 ``Warum toben die Heiden,” followed by his organ sonata in C minor (Op 65 number 2). While these are both very nice, they were still clearly outshone by the earlier Bach. When the ~~competition~~ concert was over, Bach still remained the champion, but it was a solid and respectable effort from Mendelssohn.

My colleague here at Maynooth, Joost Slingerland, and his wife Theresa, both sing with the Mornington singers who performed the choral part of this event. Kudos to them, the entire choir, and the organists. And Kudos to Mendelsson and Bach!

250 years of Good Beer

2009-09-27T02:59:00.000-07:00

September 24th of this year marked the 250th anniversary of the day when Arthur Guinness founded his beer-making factory. For an annual rent of 45£, he bought a 9000 year lease on the land his factory is built on. Nothing like planning ahead. Considering global warming, all of Dublin might be underwater before the lease comes up for renewal.

The Guinness Corporation has very cleverly invented a holiday which they call “Arthur’s Day” to celebrate the founding of their famous product which should be considered more of a mix between chocolate milk and oatmeal than a real beer. On September 24th at 17:59 (5:59pm) everyone was supposed to go to the Pub and drink a Guinness (Get it?, 250 years ago it was the year 1759). Around Dublin, Guinness also funded a whole lot of festivities – cool bands and the like at multiple locations.

As it turned out I happened to be in downtown Ireland in the late afternoon on Arthur’s day (I had just given a talk at Dublin Institute for Advanced Studies) so I stopped into my favorite little pub just before 6pm. It was standing room only, and the bartender was pouring Guinness full speed from six taps in parallel. I grabbed a pint myself and joined the crowd in watching the official countdown to 17:59 on TV. This seemed a bit too much like New Years –- except no one knew quite what to say when the clock hit 17:59. “Happy… er… Pint?”. Strangely, the event on TV was celebrated by a performance of Tom Jones singing “It’s not unusual”. This can only be described as surreal. I’m sure Arthur Guinness is rolling over in his grave.

Anyway, after finishing off my pint, I left and started walking around the city. Every single pub (and there are very many) was overflowing into the street, and every person was drinking Guinness. What an amazing marketing coup.

I wandered around Dublin observing all the people drinking Guinness (observing also that the new dress code for young women in this town involves insanely high heels which appear impossible to walk on – but this is another story). But instead of going into one of these pubs, instead I went across town to go to…

(To be continued next blog posting)

The No Spin Zone

2009-09-26T06:56:00.000-07:00

Have you ever gone swimming with your jeans on? Jeans can absorb so much water that you can wring them for about an hour before they become classified as only “wet” as compared to “sopping wet” ? Well, that is what my jeans were like when I took them out of the laundry machine when it refused to run the spin cycle here at the seminary. The young Irish seminarian who was in the laundry room washing his frock (literally) told me “Aye, I'd pray hard before using that machine... the devil himself is inside 'er”.

Maybe this is the moment when I am supposed to find religion. Instead, I have wet laundry hanging inside my room.

Me and The Priests

2009-09-24T08:48:00.000-07:00

In 1795 the British government decided to build a beautiful Catholic seminary in Ireland to train priests. If you know much about Irish history, you will realize how strange this sounds: the Brits hated the Catholics, and oppressed them for hundreds of years. Why on earth would they go out of the way to build a nice seminary for them?

Well, this is a classic (and rather brilliant) case of keeping your friends close and your enemies closer. Since there were no seminaries in Ireland, the Irish typically went to France for their religious education. Long about that time, the French were having this thing called a revolution where they were cutting off people’s heads – particularly those in the ruling class. The Brits were justifiably afraid of having folks come back to Ireland with ideas of revolution, so they decided to keep their enemies closer by building a nice seminary in Ireland to keep them at home. In this way St. Patrick’s College was established in Maynooth Ireland, just outside of Dublin, and it has been operating as a seminary, training priests, ever since.

After a few years they decided to expand the seminary to become a broader university and the location eventually became what is now the National University of Ireland at Maynooth. By the auspices of Science Foundation of Ireland, I am officially a visiting professor at NUIMaynooth for some number of weeks per years in 2009 and 2010 (This is a complex arrangement that we started negotiating back when I was still at Bell, and it is officially so confusing that I have no idea of any of the details by this time).

At any rate, for this particular visit to Maynooth, all of the low budget “regular” rooms have been booked, so I’ve been staying in the guest rooms of the seminary. I was told that there would be a conference of Bishops during my stay, and that I would have to be extra quiet so as not to disturb them. So every morning at 7 am, I make sure to crank the Led Zepplin at 9 on my stereo instead of 10.

Here is a good picture of the building where I’m staying. It has 20 foot high ceilings everywhere (that is close to 7 meters, for the international audience) and the hallways are close to the same width as height. You could march a team of clydesdales down the hall in parallel without them feeling at all cramped. I’m not sure why the monks in 1795 decided they needed to march horses down the hallway in parallel, but apparently they did. You might even be able to march an elephant down the hall if you tried.

As you can see in the photo, the windows are extremely tall – probably 15 feet high. The room I’m staying in is sparsely decorated. Just a large bed and a tiny table, and lots of extra (wooden) floor space – which I could use to play soccer, I suppose.

Standing at the position where the above photo was taken, if you turn around 180 degrees, you see the main building of the seminary in this picture --- which also houses such crucial things as the student cafeteria in the great Hall (which I would have once called Harry-potter-esque, although now I probably would just call it Oxford-esque).

I’m still entertained that there is a strict division in the cafeteria –-- one section is roped off and labeled “reserved for seminarians.” Perhaps they are afraid of the corrupting influence of evil people like me (I do have horns, you know).

Anyway, returning to the photos above, there is a legend that it is bad luck for undergraduates to walk down the path in the center of these pictures. The source of this legend is thought to be that faculty members would sit at the sides of this path and think deep thoughts when the weather was nice, and whenever undergraduates bothered them by walking down the path, the faculty got upset and made the exams just a bit more difficult.

Although the area around the university is pretty, most of it is not ancient like these two pictures. The campus is split into a north and south half divided by busy Kilcock road. There is a walking bridge over this road, with signs indicating that one should not cycle over the bridge. Every one of these signs has succumbed to graffiti by this time. My favorite one now says "No Cycling, Sasquatch". Must be the seminarians with the sense of humor.

My Delsey Suitcase

2009-09-20T08:23:00.000-07:00

I bought my rolling Delsey suitcase almost a decade ago. It is one of those rolling small black bags that you see in airports all the time. When I bought it, it was the largest suitcase size that was still small enough to fit in the carry-on – which made it the ideal suitcase. However, sometime in the intervening years, the airlines slightly decreased the size of a bag that you are allowed to carry-on (even though the suitcase will certainly fit, they now tell me it is too large almost always), and now my Delsey bag is instead the smallest suitcase that you are not allowed to carry-on to an airplane. As a result my ideal suitcase is now a bit less than ideal. But I haven’t gotten around to replacing it yet.

Last week, I was in Ireland, attending this conference, and I am staying Ireland again this week, but since I had to be in Cambridge to sit on a thesis committee on Monday, I went home to Oxford for the weekend. Arriving at Dublin airport, and checking my Delsey suitcase at the British Midland International airline (BMI) counter, I happened to comment to my friend Gunnar Moller that his carry-on suitcase was the ideal size, whereas mine is now not ideal. I think “not-ideal” is a bit of an understatement. Somehow in the course of the one hour direct flight from Dublin to London, BMI managed to lose track of my suitcase. Two days later, it still has not turned up. While I’m not crushed to have lost the Delsey (which, admittedly, was no longer ideal), I’m quite annoyed to have lost the entire contents of the suitcase. The people at BMI tell me that if it doesn’t show up within 5 days, they file it as lost and I have to negotiate with their luggage compensation people. By then, the underwear situation may start to get a bit critical. Despite my resistance to such things, I may need to actually go shopping.

PS: L’shana tova. (Happy new year in the Hebrew calendar, thus begins the year 5770)

Update Monday: Still no suitcase.
Update Tuesday: Still no suitcase.
Update Wednesday: Still no suitcase. BMI instructs me to contact the Luggage loss department. Ugh.
Update Thurdsay: Alas...

Shelob, Aragog, or Charlotte

2009-09-14T12:44:00.000-07:00

According to the British Arachnid Society, there are no spiders in the UK that eat people. However, looking at the rather large spider who has taken over my backyard in Oxford, I have my doubts.

You can see her for yourself in the picture. For reference, the garbage can in the background is a full size 40 gallon container (150 liters). The spider is about 2.5 cm from fang to spinnerette –a bit over 5cm long if you include the legs. I’m not positive, but I think she is an Argiope Bruennichi, based on the size and the striped legs, but the body doesn’t look quite like the pictures I find online (Any spider experts out there want to comment on this one?).

I had known about the spiders of unusual size (S.O.U.S.) in this country even before I moved here: I had had a frightening close-encounter with a British SOUS on one of my visits to Oxford before moving here (a story for another day). Admittedly, The British spiders aren’t nearly as nasty as the beasts that live in Australia: for example, the Funnel-Web can deliver enough poison to kill a human within 40 minutes, and can bite through most canvas sneakers. This seems to me to be a good reason to avoid the whole continent.

Despite the favorable comparison to the bigger and badder Aussie variety, the somewhat less deadly British critters still give me the creeps. There is some evidence that being afraid of spiders is learned behavior, and children do not naturally have this fear. Nonetheless, the trope of the deadly spider is certainly a common one: Aragog, Shelob, Charlotte. Ok, maybe Charlotte was not supposed to be so threatening, but E. B. White conveniently left out the part of the story where Charlotte mates and then kills and devours her lover. (She lays eggs, so it probably happened). Probably White was censored by his editors since it is a children’s book and one wouldn’t want them reading about spider-sex.

The lifecycle of most of the large British spiders is such that they are born in the spring, they grow through the summer, and get extremely large in the fall just before they mate, lay eggs, and die. I’m traveling for the next three weeks with only one more two day stop back in Oxford, and I’m hoping that Shelob in the backyard will hurry up and get on with the mating, laying eggs, and with luck she will be stone-cold by the time I get back. As far as encouraging the mating part, I left a disco ball in the window and some incense in the backyard.

Condensates - the Borg of Physics

2009-09-08T12:52:00.000-07:00

Many phases of matter consist of some highly organized arrangement of constituent particles. In many such cases of interest so-called “condensates” have the property that every particle contributes to the overall collective quantum properties of the whole. Not to make too dorky an analogy for an already geeky subject: you might think of it as the Borg from Star Trek – a communist collective of particles each contributing to an overall unison.

Once you have an organized ground state, it is a natural question to ask what the low energy “defects” of this ground state, (the quasiparticles) look like. Indeed, in most cases, it is these quasiparticles that determine the interesting physical properties of the phase of matter in the first place. All of the particles have fallen into line perfectly making a featureless background, and what you notice most in the experiments are the few regions where something different is going on. A next question to ask is what happens when you have a lot of these defects. Can the defects now start forming their own organized collective – their own Borg?

At the Quantum Hall workshop at NORDITA this month there has been a lot of discussion of what kind of condensates, or new phases of matter, can form from collections of quasiparticles in fractional quantum Hall states. This is an old question that dates back to the very earliest days of quantum Hall effect. As many people reading this might already know, very shortly after the discovery of the nu=1/3 fractional quantum Hall effect, Bob Laughlin gave a beautiful theoretical explanation of how electrons in high magnetic field can condense into a new quantum phase of matter (a Borg of electrons), thus explaining the experiment. However, very soon thereafter, additional quantum Hall effects were discovered (the 2/3 effect, the 2/5 effect, and so on). Laughlin’s theory did not fully explain these. It was Halperin and Haldane who realized that the defects (the quasiparticles) of the nu=1/3 effect can themselves organize, forming further new phases of matter. The resulting picture was a recursive construction of defects condensing then new defects forming within these new condensates.

So why revisit this issue now? Well, the new twist is an entirely new class of more complex and interesting quantum Hall states – the so-called “nonabelian” phases or “nontrivial topological” phases (drawing a distinction that all of the abelian phases are now considered “trivial”). In these cases, the quasiparticles, in addition to carrying charge (and fractional statistics), also carry interesting topological quantum numbers. It is not so obvious how such a thing can form a condensate at all, or whether it would want to do so.

There have been several approaches to addressing this problem. The first set of approaches attempt to condense the nonabelian anyon by forming a topologically trivial combination of quasiparticles and then condensing the combination in the same spirit as the old Halperin-Haldane hierarchy.

(1) An approach by Bonderson and Slingerland combines a pair of quasiparticles on top of each other in a topologically trivial combination then condenses these pairs. A more recent paper by same authors plus Moller and Feiguin shows some nice numerical data showing that these trial states are actually quite competitive for experimental systems – although from the data I saw, it was not completely convincing that there was any regime in which they clearly were better than more conventional trial states. Nonetheless, they seem to be now in the running as something that needs to be seriously considered.

(2) An approach by Levin and Halperin (neither of them happen to be at this conference) is to form a topologically trivial quantum superposition of states before condensing. (Not surprisingly, the resulting states lose all of their topologically interesting properties after the condensation ). There does not appear to be much experimental or numerical evidence of these states being realized, even for model systems.

(3) A third approach by Hermanns is a bit more confusing to describe. At first I thought that it was probably incorrect, but now I think the construction makes a fair amount sense although there are some pieces of the argument that still seem a bit mysterious to me. I’ve agreed to be on Maria Hermanns’ thesis committee, to be her “opponent” in the Swedish system, which I gather means it is my job to find holes in her arguments, so I’ll be studying this a lot more in the next few months.

(4)In the work of Schoutens and Grosberg a condensate naively looks a bit different. In this case, a condensate is made by forming a maximum density droplet of a particular quasiparticle with nontrivial topological quantum number . This case can be analyzed in great detail – determining not only the details of the condensate (which is a known phase) but also the behavior of the edge separating the mother and daughter states. (See below however, the work of (6) seems to be able to phrase this condensation again as a boson condensing).

And there are yet more approaches. In the above approaches, all of the quasiparticles form liquids. There is another possibility which is that all of the quasiparticles form a solid. Solidification would usually be considered uninteresting from a topological perspective, but here since the quasiparticles carry topological quantum numbers something more interesting can happen.

(5) In this picture discussed by ~~Gils, Trebst, and friends~~ Gils, Trebst and Friends, one might have the charge of the quasiparticles pinned in some sort of lattice, but the topological quantum number may still be able to hop around. Although the hopping my be very weak, at very low temperature and long time scale, in principle the topological quantum numbers will settle into a unique “condensed” ground state of their own hopping problem. This is somewhat like electrons forming a Wigner lattice and then looking at the spins on the wigner lattice, which at low temperature, align to form a ferromagnet (or antialign to form an antiferromagnet, which is more typical).
Finally, there is the world of more abstract nonsense:

(6) And a more abstract discussion of condensation was given by Slingerland and Bais. While perhaps a bit daunting at first, this paper is well worth the effort to read. These authors have constructed a generalized paradigm to describe condensation of one topological phase within another topological phase. The general rule is simply that you have to find a particle that is topologically a boson, then you can condense it. Anything that is not “local” with respect to the boson cannot live within the new phase, and you have to identify any two particles that differ from each other by the bosons. (There is a subtlety having to do with particle branching that I will not explain here). Pretty much all of the above cases can be described within this formalism in one way or another. Further, coset TQFTs can be described nicely within this formalism too (which I find very pretty). The down side, as in any abstract nonsense, is the generality is frequently a disadvantage as much as an advantage. Since you can describe pretty much anything, it does not give you hints as to what thing to expect.

At any rate, there are a whole bunch of ways to describe condensation of topological phases within topological phases. Seems like a popular thing to be studying right now. Resistance is futile….

Jumping out of Airplanes

2009-09-06T00:10:00.000-07:00

Eddy Ardonne is an avid skydiver. He is currently an assistant professor at NORDITA in Stockholm where I am visiting this month, and he frequently offers to take people skydiving if they so happen to be interested. Smitha Vishveshwara*, who was once Eddy’s officemate, made a jump a few years back and loved it. My colleague from Ireland, Jiri Vala, was absolutely determined to try jumping this week and encouraged me to go too.

Now, to begin with, I’m a guy who doesn’t even like to drive in a convertible because I don’t like that much wind in my face. Why on earth would I want 120 MPH of wind in my face? I’m also rather afraid of heights (yes, I know, I’ve rock climbed in the past, but I never like being near a cliff unless I’m in my harness and anchored in). But perhaps because I was completely terrified of the idea, I was also curious about it, so I started doing some homework to find out, just how dangerous is it?

Being a statistics geek, the first thing I found was that many of the statistics that you find on the web are totally bogus comparisons.

The best verified figure I could find is that in skydiving there is roughly a 1 in 100,000 chance that you will die on any given jump. It might be a bit lower for certain types of jumps, or certain jumpers, and a bit higher for others. But very roughly, this seems always to be the right number**.

But back to bogus statistics: Here’s a statistic that gets thrown around an awful lot:

“Each year about 30 people die skydiving in the United States, and that's out of over 2 million parachute jumps. Given the odds, you're better off skydiving than let’s say driving a car. Every year, over 40,000 people die in traffic accidents”

Similarly many websites state that

“you are more likely to die driving to the dropzone than during your jump”

I’m calling a loud foul on both of these: The fatality rate for driving a car in the US (and most of the western world) is roughly one fatality per 100 million miles driven. So a single jump has the same fatality rate as driving a car one thousand miles. Spending an hour making a single jump is over 100 times more dangerous than driving a car for the same hour. Perhaps it is surprising (even impressive) that jumping out of airplanes is not more dangerous than this, but still the statements being made on the web are clearly inaccurate. I’m not particularly afraid of driving a car for a thousand miles, so there is not really much good reason to be afraid of making a single jump. However, if you make it a habit of jumping out of airplanes, you have to accept that it can start to become a significant added risk.

While I was searching for more statistics on the matter, I found quite a few interesting things about skydiving injuries. One of the strangest facts is that for solo student jumpers (not jumping in a tandem) apparently women have over twice the fatality probability than men. No one seems to know why this is, but it is an established fact. There are some other interesting statistics regarding how many times a fatality occurs from a real splat (no parachute deployment), versus from other means such as mid air collisions, improper landing with proper chute deployment etc. It turns out that the real splats account for less than 30% of the fatalities.

Another interesting stat (which is harder to pin down from data available) is that non-lifethreatening minor injuries are apparently pretty common - the “injury requiring medical attention” rate is roughly 1 out of 1000 jumps. Most of these are minor sprains, breaks, and so forth. But a few are more serious. If you compare this to say, a few years of participating in any other sport, you would probably have a similar rate of minor injuries. (One should be warned however that certain medical insurers do not cover skydiving injuries whether or not they are minor).

Anyway, Jiri and Eddy did go jumping yesterday and they both came back in one piece. I didn’t go. It really came down to a decision of whether I wanted to spend most of a day preparing for a 60 second drop (which I didn’t’ think I would enjoy all that much anyway). I think the main attraction to the idea was just that I was a bit afraid of it.

Maybe when I’m visiting Stockholm next year I’ll think about it again.

*Congratulations to Smitha on her marriage last month.

**It appears that this number does not include the possibility that the small plane you are in crashes before you jump out of it. It is hard to get numbers on the added risk from plane crashes, but my best estimate is that it is unlikely to more than double the risk.

Pripps Blå

2009-09-05T05:29:00.000-07:00

Perhaps a better name for it should be BLAH.

Pripps Blå is one of the most popular beers (if not the most popular beer) in Sweden. Blå means “blue” and it is pronounced closer to Blow or Blough. On Wikipedia it is explained that Blå is brewed with 51% barley grain, which is the minimal fraction allowed by law if you want to call yourself a beer. (Not sure what the other 49% is – probably some cheaper grain like corn or rice). Despite the jeers of all of the people around me, I actually like the stuff. It reminds me of similarly terrible American beers like Bud Light and Miller Genuine Draft. It tastes roughly like water, and it comes in big aluminum cans.

So here’s the cool thing about Blå. You can get Blå that is 2.2% alcohol (which you could easily drink for breakfast or lunch and not even notice that it was alcoholic) or you can get the 2.8%, or the 3.5% or the 5.2% or the 7.2% (which is pretty strong). And as far as I can tell, they all taste exactly the same. Nice to have options.

Singing in Swedish

2009-08-29T01:03:00.000-07:00

In Swedish, the most common word for “Hello” is “Hej” which is pronounced more or less “Hay”. There is an interesting history to this word posted here about why this greeting was not “the greeting of the masses” until the 1970s. Frequently people repeat it twice: “Hej Hej”. The same website seems to indicate that this implies excitement to see someone (Although the woman at the NORDITA cafeteria seems to use “Hej Hej” for every single customer, and she can’t possibly be excited about every single one).

After a day or two of figuring out that “Hej Hej” is actually a greeting, I started noticing that a lot of people seem to sing it more than say it. Of course not everyone does it the same way, but I’ve heard an awful lot of people who put the second “Hej” almost exactly a major third below the first “Hej”. The Swedish language does have a bit of a sing-song quality to it, but I don’t really detect any other consistent musical intervals in the Language except for when people say hello.

Geek interlude: a major third is a frequency ratio of 5/4=1.25 on a natural scale but is a frequency ratio of the cube root of 2 (1.2599..) on an equally tempered scale.

Speaking of Swedes and music: yes indeed, I have heard a lot of ABBA in Stockholm (Hey, come-on, admit it, you love them too). I was hoping to hear some Ace of Base and the Cardigans too (Yes, they are both Swedish.)

The International Week of the Gaffnian

2009-08-22T10:18:00.001-07:00

Isn’t it great when you manage to get in one room a majority of all the people in the world who are interested in the same esoteric aspect of an already esoteric subfield of theoretical physics?

Keeping in mind that about half of the people who actually care about my particular pet projects within my sub-subfield are actually at NORDITA this week, I took the opportunity to declare last week to be the international week of the Gaffnian, being that most of the speakers at NORDITA were speaking about the Gaffnian in one way or another.

So for the more general physicists in the audience, I’m sure many of you are wondering what on earth a Gaffnian is. The terminology is a mathematical-phonetical-linguistic joke that I managed to get into print. The Gaffnian is a trial quantum Hall wavefunction we introduced in several years ago in this paper (In the paper, the joke is explained… sort of). For the experts it was proposed to describe the nu=2/5 quantum Hall effect, but probably instead describes a nearby critical point. This Gaffnian wavefunction has remained a bit of an enigma. It is nice because it is based on a conformal field theory – but it is not nice because it is based on a nonunitary CFT, which means that it cannot represent a state of matter with a gap (if it is a critical point it makes sense that it has no gap). However, the numerical overlap of this trial wavefunction with other wavefunctions, such as the composite fermion wavefunction, believed to represent the ground state of a gapped state of matter is about 99% even for reasonably large finite sized systems. So apparently the 1% difference between these two wavefunctions makes all the difference in the world to the physics. How this 1% changes the story is not very well understood.

A year or two after we introduced this Gaffnian wavefunction, interest boomed when Bernevig and Haldane pointed out that the Gaffnian is actually just one of the simplest of many possible trial quantum Hall wavefunctions (for general nu=k/r) that can be described as Jack polynomials (these are a family of special functions with lots of nice properties). But after a fair amount of grief it turns out that, except the previously known Read-Rezayi series, all of the Jacks suffer from the same nonunitarity problem that the Gaffnian suffers from – so they probably describe a whole set of quantum Hall critical points. The reason the Gaffnian is so interesting to study is because this is the simplest of the nonunitary Jacks and presumably understanding the physics in that case will tell us a whole lot about the more general cases.

The Gaffnian also has an appealing advantage (not shared by all Jacks) that it is the exact ground state of a particularly simple Hamiltonian. As such, quite a few exact statements about it can be made. This gives one a starting point for analysis that gives a bit of hope that we might actually be able to unravel its mysteries.

Stockholm

2009-08-22T07:31:00.001-07:00

When I wake up in the morning in Stockholm, I catch the subway at Thorildsplan, change from the subway to the bus at Odenplan, and then get off the bus at Valhallavägen. I somehow have the feeling I am living in a Marvel Comic. Should I have a constant fear that Ragnarök and Fenris Wolf are just around the corner?

Making the eternal conflict between good and evil all the more cartoonish (or maybe making the eternal conflict between heavy metal and the rest of the world more obvious) it seems that every word in the Swedish language is decorated with an unreasonable number of umläuts.

But Marvel comic jokes (and jokes about characters in Marvel comics) aside, Stockholm is actually a very nice city. Very much as you might expect of a northern european city, Stockholm has its share of canals, bridges, pedestrian areas, open air markets, gardens, castles, museums, cafe's, and tall blonde people. Overall not much to complain about.

The NORDITA center (Nordic Center for Theoretical Physics) moved to Stockholm from Copenhagen where it had been for half a century (This move struck me as a great loss for Copenhagen). Like the KITP and the Aspen Center, the idea of the center was just to have a place where theoretical physicists could come and hang out for extended periods of time and work together. They've done a great job of making it comfortable and pleasant for all of their guests. I've been here for almost a week already and I'm staying three weeks more --- I think this is going to be a very nice stay.

The Summer of Being Erdős

2009-08-15T07:59:00.000-07:00

Paul Erdős (pronounced Air-Dish) was one of the most prolific mathematicians who ever lived – he was also one of the most eccentric. His life has been immortalized in the documentary film “N is a number” and in the bestselling book “The man who only loved numbers.” (which is a very fun read, even if you don’t like Math).

One of the unusual things about Erdős is that he was a vagabond: Except when he was very young, he never actually had a home - he just spent his life hopping from one mathematics conference to the next. And when there was no conference to visit, he would just pop in on one of his many collaborators for several weeks, working on a mathematical paper or two for a while, before moving on to his next visit. All of his possessions fit into one suitcase. When I read about this lifestyle, it certainly seemed a bit crazy.

I wish I could claim to be as prolific and as important as Erdős was. I’m not. But I am starting to share one of his other eccentricities – being a vagabond. And it isn’t nearly as crazy as it sounds. You see, over the course of this summer, I have been hopping from one locale to the next, living out of a suitcase. Between the day the spring semester (Trinity) ended (June 18) and the day the fall semester (Michaelmas) begins (Oct 4), only a mere handful of days will be spent at my “home” in Oxford. The rest of the time I’ve been all over the map: California, Italy, Colorado, Netherlands, Germany, Sweden, Ireland, …. Right now, I am about two-thirds the way through the summer, and I’m still holding up pretty well (an annoying cold and a damaged rib not withstanding). Living out of a suitcase turns out to not be that difficult.

Wherever I go, there is interesting physics to be done, and interesting people to talk to. And in the modern era it is not even that difficult to keep in touch with friends and family wherever I happen to be. I’m not sure I could reduce all my worldly possessions to one suitcase, but it might not be such a bad idea to try

Oh, and for those who want to know, my Erdős number is 3 (via Mike Freedman and Laszlo Lovasz).

No Satisfaction Redux

2009-08-10T02:39:00.000-07:00

A few weeks ago I blogged about hearing the talk by Boris Altshuler purporting to show that the adiabatic quantum computing scheme for solving the 3-sat problem is not going to work.

To review: 3-sat is a particularly simple case of NP complete problem (such as traveling salesman) where it is not known if a solution can be found in polynomial time or not. Showing that NP problems can be solved in polynomial time (or showing the converse) is perhaps the most important outstanding theoretical computer science question. The adiabatic quantum approach purports to have an approach for finding such a solution in polynomial time.

The essence of the scheme is to construct a Hamiltonian H_P whose ground state is the solution to the problem. Initialize the system in a a known ground state of a known simple Hamiltonian H_I . Then adiabatically vary the Hamiltonian

 H = t H_P + (1-t) H_I

As t goes from zero to one, the adiabatic theorem keeps the system in the ground state so long as the gap does not close. So the issue boils down to how big is the gap. Most people (including Altshuler) think that the gap gets exponentially small which means that the scheme takes exponentially long to run (which is then uninteresting).

Last week at Aspen I heard an informal talk by Eddie Farhi, one of the proponents of adiabatic quantum computing, on the same subject. Although Altshuler’s talk was pretty compelling, Farhi made a few notable points.

(1) To a computer scientist, the 3-sat problem is “solved” in polynomial time if you have an algorithm that ALWAYS finds a solution to the problem in polynomial time. However, it is still interesting (although not equivalent) if you have an algorithm that typically finds a solution in polynomial time. This is a bit less stringent of a requirement.

(2) Numerics simulating the adiabatic quantum approach to solving the 3-sat problem (for up to 100 bits or so) seem to indicate that it will work after all (that the gap is not exponentially small). These numerics have been done by people like Peter Young, who is certainly no slouch. One can always argue that when you look at more bits the algorithm will suddenly fail, but apparently there is no indication of this as of yet.

(3) Finally, it was pointed out that even if generically you have an exponentially small gap, you still have the freedom to construct an arbitrary

 H = t H_P + (1-t) H_I + H_{extra}(t)

And if any H_{extra} can be thought up that generically keeps the gap large, then you have a good solution.

My gut feeling is that despite this evidence to the contrary, in the end, this is not likely to provide a polynomial solution to NP complete problem. I even think it is unlikely to typically find a solution.

Apparently Alexei Kitaev, who is officially a genius by the McArthur foundation, apparently stated that he thought the gap HAD to be exponentially small based on the reasoning “otherwise the algorithm would work”.

Hiking and Climbing (and a little Science): Day 2

2009-08-05T23:25:00.000-07:00

The next morning, Carissa and I started out at around 8:30 am to climb Castle Peak. (Lin was having trouble with her feet so she did not join us.) Had we known it was going to be difficult we would have opted for a more alpine start.

Castle Peak, at 14,265 feet, is the tallest mountain in the Elk range (the 12th highest in Colorado) and is also one of the most frequently climbed. From the northeast, there is a very “well worn” route that gets you to the top with little trouble. In fact, you can drive to within about 1500 feet from the summit if you have a sturdy jeep.

The standard routes to ascend Castle Peak is along the northeast ridge (shown in blue on the map). We intended, however, to climb the peak directly from the west from the hotsprings (shown red on the map). The hike from the trailhead to the hot springs is along conundrum creek from the north.

According to our guidebook, the approach from the west is a reasonable climb as well, but it turned out to be much more difficult than we expected. In retrospect, scanning around the web there are several reports of people having trouble on this route exactly the same way we did. The problem, in short, is that the mountain is made of bad rock and is simply crumbling away. There is no clear path up the mountain from the west, just one giant steep slope of scree and talus -–- small rocks that have a tendency to avalanche down the mountain, carrying you with them. (In fact, “scree” is from the norse word for “landslide”. Talus, is from french and means roughly the same thing, but sometimes refers to slightly larger rocks).

Physics 1: Angle of Repose. When rocks are piled on a slope, there is some critical angle of steepness of the slope beyond which the rocks starts falling down the slope. This is known as the angle of repose. If the steepness of your slope is much less than the angle of repose, it is unlikely there will ever be much of an avalanche. If the steepness of the slope is greater than the angle of repose, it is completely unstable and is likely to avalanche at any moment. In the photo here, I am walking over a field of talus that is a bit too close to the angle of repose.

Many physicists have spent many years studying rock-piles and avalanches. What is interesting is that such piles have a tendency to tune themselves precisely to the angle of repose -- an example of what is known as "self-organized criticality". If you assume that the rocks are always being added from above (say, from the mountain itself crumbling higher up), then the angle of the slope continually increases as rocks are added until it hits the angle of repose, then there is an avalanche that reduces the angle a little bit, and the angle starts growing again -- such that the angle of the mountain is always near the critical angle of repose. Another interesting feature is that avalanches occur on all length scales -- sometimes small ones, sometimes huge ones. (For the experts, yes I know that sandpile models do not really behave like real sandpiles and rockpiles, but some of the rough ideas are similar).

At any rate, Carissa is a very experienced climber and is extremely sure-footed and quick over bad surfaces (as well as being very good at trail finding -- to the extent that a trail existed in the first place). At some points I started thinking that she must be half mountain goat. In comparison, I felt very clumsy and slow moving. To make matters worse, there was a great deal of ice, frost, and frozen hail (from the storm the previous night) on many of the surfaces which slowed me down even more.

As shown in red line in the map above, we started by traversing northeast along the side of a smaller mountain (I think called Castleabra) to arrive at a large amphitheater and turn southeast to continue climbing. Half way up the amphitheater, we could finally see the peak, but it was not so obvious how we were supposed to get up from the amphitheater onto the ridge that leads to the summit.

Even from very far away, we could see that there were some people up on the ridge leading to the summit. These people had obviously arrrived on the ridge from the other side of the mountain. A few of them seemed to be looking down at us and wondering how we were planning to get up there. (More likely they were looking to the west to see if any bad weather was heading this way.)

There was absolutely no one else on the west side of the mountain that day. This was actually a good thing. Many times I would accidentally kick a small rock and, with the mountain being at the angle of repose, it would tumble a long way down --- sometimes starting a rather substantial avalanche. I was very careful never to be either directly above or directly below Carissa (although it seemed that she was starting avalanches far more rarely than I was).

Actually, it was not quite true that no one was on the west side of the mountain. Just about at the place where we turned from northeast to southeast, we ran into a large heard of mountain goats. You have to look hard in this photo to see them --- there are about a dozen of them -- they are pure white in the middle of the frame just below the small cliff band. (Maybe they were fooled by Carissa's sure footing and they thought she must have been a mountain goat too so they came over to say hi.)

Our guidebook simply said something like "Continue up to Gain the Saddle between Castle and Connundrum (to the north), then follow the ridge to the summit". This instruction seemed more and more mysterious as we continued up the amphitheater. Here's a picture of Carissa leading the way up a snow field through the amphitheater.

(Yeah, I know, I'm not a good photographer).

Even though we did not have proper snow equipment, the snow was still easier going than scrambling through the nasty scree.

Physics 2: Static and Sliding Friction. Everyone knows this principle: once you are sliding, your friction on the surface goes down and you slide even more. An obvious point here. For God sake, don't start sliding!

Meteorology
The weather pattern in these mountains is that thunderstorms tend to arrive in the afternoon. To add to this, all week long (and possibly all summer long) storms had been rather frequent and severe (as evidenced by the storm the previous evening). The climb had been very slow going, and at about 12:30 we still had a long way to go to the top. There were starting to be some clouds in the west, and we were starting to get worried about how bad the situation would look if a storm rolled in quickly. If we felt exposed sitting in a thunderstorm at 11,200 feet the night before, it could only be worse up on a peak near 14,000 feet.

"Predictions are hard to make, especially about the future" This quote is sometimes attributed to Yogi Berra, and sometimes to Niels Bohr, and on Wiki-Quote it is attributed to Robert Petersen, and I have no idea who that is. Whoever said this, it seems quite true about the weather. The truth is, I know almost nothing about meteorology except the important principle that today's weather is probably going to be like yesterday's. Unfortunately, yesterday's weather (and the day before and the day before) were not so good.

To add to the meteorological concerns, we still did not see how we were going to "Gain the Saddle". Here is a view towards the summit from where we stood. At any rate, given that the path was not at all clear (and perhaps not even possible without more serious climbing equipment), we made the decision to turn around and start heading down. We still had a very long day ahead of us -- as once we reached the campsite we still intended to walk all the way out to the trailhead that night.

Here is a photo of us where we turned around. (Photo was taken by Mr. Timer, not by a mountain goat). You can see a few clouds behind us, and to the south (off left of the photo) there were a few more. Here's another report on the web of another guy who also turned around at roughly the same place.

You might think that the hardest part was over, having done all the up-climbing at this point. Unfortunately, that was far from true. Down-climbing was just as difficult and slow. With tired legs (and suffering just a bit from the altitude) my legs were feeling pretty shaky, and on a number of occasions I lost my footing. Falling on my ass in the rocks is certainly not pleasant, but what I was really worried about was if I started tumbling. You see, according to the principles of self-organized-criticality described above, some tumbles would likely be short ones, but other ones might be longer ones. And according to the principles of sliding friction, once you get tumbling, it is really hard to stop.

Well, sure enough, at one point, I did take a bit of tumble. Luckily I caught myself in only about 10 feet. Beyond scrapes and so forth, I walked away with a rather bruised rib; and ~~four days~~ two weeks later, I still can't sleep on my left side. Not a serious injury, but a bit annoying. After that fall, I decided that I had better start walking even more slowly and more carefully. As a result of my slowness, we did not make it back to camp until after 3pm.

Here's a picture, just as we are getting close to camp and we are finally off of the nasty scree. Do I look tired yet?

We finally made it back to camp, and Lin had very kindly prepared us dinner with lots of water. We then packed up our stuff and started the 8.5 mile hike back to the trailhead that night. We had headlamps just in case, but we were hoping to make it back before dark nonetheless, so we tried to hustle.

From the hike out, we had one last really good look at Castle peak.

To quote Carissa in a classic use of double negative, "Well, it is certainly not unsteep".

We made it to the trailhead by dark.

Hiking and Climbing and Science: Day 1.

2009-08-04T07:48:00.000-07:00

Last weekend while hiking with Carissa and Lin, I realized that the great outdoors is actually a great place to learn about science. This blog posting is going to be a combined report of our little weekend adventure, and some fun science along the way.

Conundrum Creek Trail:
The 8.5 mile hike from the trailhead is not a particularly hard one, even with full packs. It rises only a few thousand feet, and the trail is a smooth and beautiful walk. At the end of the hike, at 11,200 feet above sea level, is a campsite with some delightful hot springs which are almost famous according to this article. (No, that is not us in the photo).

Geology: The fact that such geothermal hot springs exist at all simply amazes me, but indeed they do exist, and are not even so uncommon in this part of the country where the ground was once volcanically active. In short, the water flows deep enough underground to get near a geothermal hot spot, and it comes up plenty warm. Sometimes it even comes up steaming as a geyser, or simply as water too hot to enjoy sitting in. The conundrum creek hot springs are particularly nice because they don’t smell like sulfur and they are just about bath temperature. After our hike, we had a nice soak.

Biophysics at Altitude 1:As you go to higher altitude the air pressure drops. At 11,200 feet, the pressure is only about 2/3 what it is at sea level. It is kind of surprising that the human body can adapt to such changes so readily. (However at only another few thousand more feet higher, extremely serious altitude sickness becomes common). A frequent word of advice when you travel to altitude is to drink a lot of fluids. This is not just because it tends to be dry up at altitude, but rather has something to do with helping your body develop a new chemical balance with the lower ambient oxygen levels. I scanned the web for a more detailed description of exactly why fluids help you adjust to altitude, but I did not find any good answers. If any biologists or MDs want to leave a comment I’d be much appreciative.

Since I only arrived at altitude in Aspen a few days earlier, I should have been a bit more careful about getting enough fluids. I had some pretty nasty leg cramps that evening (in places I have never had them before) and I think I can place the blame squarely on the altitude and my not taking enough water.

Biophysics at altitude 2: Maybe mosquitoes in Colorado are just plain stupid, or maybe they are genetically different from other mosquitoes – but in short, these critters are about as fast as Slowpoke Rodriguez, the slowest mouse in all of Mexico (i.e., very slow – and I apologize for the politically incorrect reference to one of my favorite bizarre loony tune characters). On the east coast (where people even talk quickly) you have to really have fast reactions to successfully swat a skeeter. However, out in Colorado up at 11,200 feet, swatting skeeters is like racing a running snail. Maybe this is because the air is so thin that they can’t get enough “traction” with their wings to fly away quickly. Or maybe they are just lethargic from lack of oxygen in their blood. Any entymologists want to ring in on this one?

Added: I asked around, and most people seem to think that the average mosquito is this slow and it is the east coast variety that is Speedy Gonzales.

Thermodynamics: As air rises and expands, it gets colder. A rough rule of thumb is that air drops about 5.5 degrees Farenheit per 1000 feet (roughly 1 degree Celcius drop per 100 meters). If you want a nice physics explanation of this phenomenon, see this page. At any rate, since Aspen is at 8000 feet, and at night it gets to be about 50 degrees, I should have expected it to reach about freezing up at 11,200 feet – and indeed, this was just about the temperature at night. Brrrr…

Since it was quickly getting cold out once the sun started to set, we had a quick dinner then jumped into our tents and into sleeping bags to keep warm. Unfortunately, at about 11pm, the weather turned very suddenly nasty and we were hit with a massive thunderstorm complete with violent hail. The thunderstorm hovered overhead for only a few minutes – but being rather exposed up at 11,200 feet – those few minutes passed extremely slowly.

Speed of Sound: When lightning strikes, you see the flash essentially immediately, since the speed of light is extremely high. But the speed of sound is slow, so you don’t hear the thunder until a few moments later. With sound moving at about 300 meters per second it is easy to figure out how close the lightning is striking. Ever since I was a kid, I’ve been counting the time between flash and bang to see how far the lightning really is. Every five seconds is a mile. When the time between flash and bang got to be about a second, (and the thunder was sounding awfully loud) I started worrying that we might be in a bit of trouble. Then it got down to half a second. --- then a bit less. Lightning striking within 100 meters from my tent. Yikes!

Electricity: It is hard to overstate the strength of lightning. The temperature of a lightning bolt can reach tens of thousands of degrees Celcius, and lightning hitting a tree can easily cause the tree to simply explode. The electrical power of a lightning bolt can reach a billion watts - on the order of the power output of a large nuclear power plant. And while the power of a single bolt remains “on” for only about a second, it can do an awful lot of damage in that time.

So, given the danger of lightning, what can you do to avoid getting zapped? The principle to keep in mind is to try to avoid having the lightning go through you. The best thing to do is to get inside a modern building or a metal vehicle. The metal in these objects is a great conductor (a so-called Faraday cage) and even if it does get hit, the electricity gets diverted around you. Unfortunately, when camping, this is not really an option. Here are some tips from the physicist for what one can do

(1) Don’t be the tallest thing around. (This should be obvious. You don’t want to be on the very top of a mountain).

(2) Don’t stand near the tallest thing around, like a tree, or anything sharp or metallic that might attract the lightning. (Lightning can strike the top of the tree, run down the tree and then jump to you)

(3) Don’t touch anything conductive like a metal fence, a long wet rope, or a large pool of water. The lightning can strike the object far away and then run along the conductive object to hit you.

(4) Touch the ground at only one point – i.e., keep your feet close together and do not lie down. The point of that when electricity is running through the ground away from a strike, you do not want the electricity to find you to be a more conductive path between two points than the ground is – thus going up from the ground, through you, and back down into the ground. Cows are often victims of lightning because their feet are so far apart.

(5) The thicker the insulation between you and the ground, the better. Wear your thick boots, stand on your backpack, or on a plastic ridge-rest or similar.

So if you are out camping, the best thing you can do in a lightning storm is to get away from tall trees in some low area (but not into the center of a flat field where you are the tallest thing around), stand on something insulating, put your feet together and crouch down.

Anyway, as the lightning storm quickly approached, I started putting on my hiking boots –preparing to follow my own advice. But in the dark, finding the headlamp, to then find my shoes was not so easy, and by the time I had them on, the storm was already receding, and I had already avoided getting zapped. Also, by that time, my tent was almost collapsing from the weight of the hail that had fallen on it. Once the hail stopped falling, I got out of my tent, looked around to see if anything was burning (nothing was), brushed off all of the hail from my tent, and climbed back into my sleeping bag to go to sleep.

Carissa reported that Lin’s first comment in the morning was “I hope Steve is still alive”

Aspen

2009-08-02T09:28:00.000-07:00

The Aspen Center for Physics is summer camp for nerds. Supposedly the rarified atmosphere and the natural beauty of the environment inspires the thinking of very deep thoughts. Whether or not this is true, the Center is still a great place to do science. Just on the border of the town of Aspen Colorado, and within earshot of the Aspen music festival tent and the Aspen Institute, the Center is about as pleasant as any one could imagine for just hanging out and thinking. Theoretical physicists (along with a few mathematicians and a few experimentalists) come from all over the world every summer to spend a few weeks here, to talk to other experts, and just to decompress and clear their minds. At any given time during the summer, something like 50 scientists are here.

The scientists are housed in ski-lodges that are vacant for the summer (sometimes these can be pretty ritzy) and are given shared offices at the center. We are given bikes for transport (unless you prefer walking, like I do – since it is harder to stop to pet the dogs when on a bike). Coffee is always plentiful, cookies are at 4pm, and barbeques are every Tuesday. Hiking, Climbing, and Mountain Biking are always nearby and are very popular among us nerds.

Like the KITP in Santa Barbara, the success of this place is, to a large extent, due to the fact that everyone wants to come here, so the Aspen committee is always able to choose visitors who are smart and interesting and fun to talk to.

A short video about the Aspen Center for Physics is spliced at the beginning of my public lecture from my previous post.

Public Lecture

2009-07-30T07:18:00.000-07:00

Last night I gave a public lecture in Aspen CO which went over pretty well. It will be streamed tonight at 9pm mountain time, and you can download the whole thing here anytime thereafter (maybe even before). I encourage even the most science-phobic to try watching it (you know who you are).

After the lecture (off camera) I got a lot of good questions from random audience members who were too shy to ask in front of the entire room. There was one question that really stumped me: Does anyone know of a good book about quantum computation for the lay-person? Eddie Farhi (who introduced the lecture) is a mainstay of the field of quantum computation, and he couldn't think of one either. There is a book by Seth Lloyd, but I don't know what it contains (or if I approve of it).

Added: Two minor techincal problems with the video (1) you could not see the laser pointer at all, so when I pointed and said "this thing", you have no idea what I am pointing out. (2) in a few places the resolution of the video is not as good as one would like. Despite these problems, I am reasonably happy with the outcome.

TV Interview

2009-07-27T16:15:00.000-07:00

On this web site I am interviewed as a preview for my public lecture on wednesday. I haven't watched the interview yet.

I apologize in advance for the shirt. Due to travel difficulties (getting to be a theme in my life), I literally walked off the airplane and into the tv studio.

The file takes a long time to download on my computer -- maybe it will work better on yours. I think it is also being streamed tonight at 8:30PM mountain time here.

Added: I just watched the interview.. and after being horrified by my shirt as well as my big hiking boots, I actually kind of liked it.

Added: Jeremy Bernstein pointed out to me that it was more von Neumann who wrote down all the pieces of the modern computer, not Alan Turing. Although Turing still gets credit for the concept of the Turing machine.

Ye Olde Saw: Yet Another Travel Horror Story.

2009-07-27T06:22:00.000-07:00

I carry my passport around with me a lot because I travel so much. But when I am at home at Oxford, I stash it in a “secure location” in my house. (I believe Dick Cheney may be hiding there too). Where is this “secure location”? In a drawer built into the bottom of my bed. (I blogged about this bed previously here and here).

Anyway, as I was finishing my preparations to go on the road for the next month, with only about half an hour before I had to be on the bus to heathrow, I went to retrieve my passport, and mysteriously the drawer was stuck shut. I tried yanking a bit. No dice. I tried prying a bit. Nothing. Screwdriver. Nada. Hammer. Zip.

This bed was an assembly-yourself deal, so I start disassembling the entire bed piece by piece. In twenty minutes, I am sweating profusely (literally and figuratively) and I have the bed disassembled down to its constituent minimal pieces. But I still can’t get into the damn drawer.

Cost of bed-frame: 300 £. Cost of plane ticket: 600 £. Time remaining: about 10 minutes.

Out comes ye’ olde saw. In five minutes, I have my passport, and I have a great big hole in the base of my bed with a lot of sawdust on my bedroom floor.
Sadly I missed the bus, but caught one only half an hour later. Unfortunately, this was not good enough. I ended up missing my airplane by precisely one minute. Actually, this is the first time I have missed an airplane by being late to the airport. I’m usually one of those people who gets there four hours in advance just to be careful. Exactly one hour before the flight was scheduled to leave, they officially closed the flight and even one minute later, I could not convince the folks at Continental to let me on (I suspect they had oversold it; and closing it promptly was a cheap way to fix the problem – I noticed that most other flights to the US did not close until 20 minutes before the flight).

[Here’s something to think about. When I am one minute late for the plane, I get bumped. If the plane is one minute late.. how can I bump them? ]

Added: I managed to get a flight only four hours later. Exceedingly annoying, but not tragic. Not sure what I am going to do about the bed though.

Comment Policy

2009-07-21T05:51:00.000-07:00

Those of you who have been leaving comments on my blog... please keep doing so! And all you stalkers are encouraged to start doing so.

You may have noticed, however, that comments are not being posted immediately. This is because I am now examining the comments before they get posted to avoid spam postings. Be assured, however, that anything you want to say will be posted, so long as it is not overly offensive and does not contain an advertisement for Viagra or similar. Those of you who want to read ads for Viagra or similar, I'm sure you will be able to find many many of them elsewhere on the web.

Physics Report from Dresden

2009-07-20T14:37:00.000-07:00

The TOPO09 conference in Dresden last week (I dare you to find me in the group photo on that page... like where's waldo) was full of extremely good talks. I missed the first day of the conference, so I can’t comment on that. But in the remainder of the conference, there were two topics that stood out as themes: topological insulators and 5/2 physics.

Topological Insulators:

As everyone knows there are metals and there are insulators. In metals, the electrons can move around and conduct electricity, whereas in insulators, they can’t. When you have an insulator, the electrons can be non-mobile for any one of a number of reasons . But at some level their lack of mobility always comes down to the same type of story: The electrons fill up all of the low energy orbitals (like orbitals in an atom) – and the next lowest energy orbital is at some higher energy (i.e., there is an energy gap). So in order for an electron to move around, it needs to first jump up to a higher orbital, which at low temperatures, it cannot do (room temperature can be “low” compared to the relevant energy spacing).

Now consider the simplest possible model of an insulator: A simple crystal, with no disorder, and non-interacting electrons, such that all the low energy orbitals (bands) are filled and there is a gap to the next lowest state for the electrons (this is known as a band insulator). Since the physics of insulators was first described about 80 years ago, it was assumed that all such insulators are more or less the same. Well, we have recently discovered that they are not all the same. Some fundamentally new physics can occur when the constituent chemical elements of the insulator are down near the bottom of the periodic table.

What happens near the bottom of the periodic table is that relativity becomes important. (HUH?). Yes, that’s right – Einstein. Electrons in heavier elements are moving “faster” than electrons in the lighter elements. When they move fast enough you have to think about relativistic effects, and one of the first relativistic effect is that the spin of the electron and the orbital motion of the electron become coupled (so-called spin-orbit coupling --- in fact, you can argue that the existence of electron spin is relativistic in the first place). If the spin-orbit coupling is strong enough, the insulator can develop some completely new properties. However, unless you know what to look for, you won’t notice that it has changed, because it is still an insulator. I suppose this is why it took 80 years for us to figure out that all insulators are not the same.

Among the cool properties these new “topological” insulators is that they have conducting surface states that cannot be eliminated with any amount of disorder or structuring of the surface. This is extremely unusual and leads to all sorts of new possibilities.

At the Topo09 conference last week, Charlie Kane, a prof at UPenn, gave a super talk about these new topological insulators and all the cool stuff you can do with them. Kane is perhaps the person most credited with figuring out that this whole new class of materials exists. However, one of the other people who is highly credited for developing this new field is Rahul Roy – a lowly graduate student at the time he started making important contributions to the young field. I've managed to recruit Rahul to come to Oxford for a postdoc next year. I hope to work with him a lot on this new and exciting field.

5/2 physics:

I’ve blogged about this before. here and here, so I won’t belabor the point. But in brief: there are an increasing number of people discussing whether the new experiments on the “5/2 quantum Hall interferometer” is really showing evidence of a new type of particle – the nonabelion. I won’t say that I know what to make of the data – I certainly don’t know. The one thing I do think, however, is that the “orthodox” interpretation – what people want to see – is probably not what is going on. There are just too many problems with the story. In fact, the more I look at the data, the more nothing seems to fit. Add to this issue that the data is pretty ratty to begin with, and I think the evidence for the orthodox theory starts to look vanishingly small. I don't think the data is just noise though -- so something interesting is happening. But I think it will take a lot of headscratching to figure out what it is though -- and probably a whole lot more data.

Travel: Things that Make You Go “Huh?”

2009-07-18T02:03:00.000-07:00

There were thunderstorms across Germany yesterday so my plane out of Dresden was delayed. The Lufthansa people in Dresden more or less promised that I would still make my connection in Munich, but there was a huge backup at passport control to get into the “international” part of the airport and (even pushing my way to the front) I ended up missing the connection. The Lufthansa people did manage to get me booked on a plane early this morning and found me a hotel for overnight.

To get out of the airport to go to the hotel, however, I had to go back through passport control --- essentially re-entering Germany from the international terminal of the airport. Going through the passport control the bundespolizei looked at the stamp in my passport and asked “You left Germany today… and now you are coming back into Germany?”. I explained that I had missed my international connection and now I was going to a hotel for the night. Well, apparently such a thing had never happened before because the bundespolizei had to get on the phone with four of his managers and I stood waiting at the passport control booth for about half an hour. Apparently this was cause for great concern because it was absolutely verboten to leave and enter again so quickly.

Am I completely wrong to think that this is completely absurd? Wouldn’t you expect that such a situation must happen hundreds, if not thousands, of times per day?

I’m thankful only that I am not from a country that requires a visa to visit Germany. No doubt they would have thrown me back to international territory to sleep on the floor.

Dresden

2009-07-18T01:58:00.000-07:00

My first visit to Dresden was in 1990 (the same summer as my first visit to Oxford). This was very shortly after the fall of the Berlin wall and the city was not used to many visitors. My memory of the city was that it had not remotely recovered from the firebombing of WWII which literally wiped it off the map in one night. Forty-five years later, there were still large sections that were still simply rubble. And much (if not most) of the construction and reconstruction since the war were hideous eastern-block buildings.

Since the reunification of Germany, the real reconstruction of Dresden has begun. The historic churches and palaces of Dresden have been slowly reassembled with combinations of new stones, and old stones recovered from the rubble. Although the reconstruction is far from finished, the city is already quite beautiful now. One can almost imagine what it looked like in the 1800s when it was the center of power in Saxony.

Help! I’m being assimilated:

2009-07-18T01:51:00.000-07:00

I was on the airplane from London to Munich (and on to Dresden) and the stewardess came around taking drink orders. The two Brits sitting next to me both ordered tomato juice, and it sounded good to me, so I ordered one too. But when I ordered it, I had a moment of panic. I ordered “tomAHto juice” not “tomAYto juice”. The first chink in the armor has appeared. Next thing you know, I’ll be eating clotted cream and liking it.

A pun and a clarification

2009-07-09T23:48:00.000-07:00

If you know the rules of bowling, you will remember that the most you can score in one game is 300 points. Well, there is an old joke about a guy who “bowled three hundred and won” (it’s a pun, it doesn’t work well written: 301 versus 300 and won). This type of linguistic confusion appears to be the source of a rumor that was circulating in the physics community about the exciting data I mentioned last week. To clarify: Eva Andrei observed quantum hall effect in graphene at filling fraction 3 AND at filling fraction 1/3. She did not observe quantum hall effect at filling fraction 10/3 = 3 AND 1/3.

No Satisfaction

2009-07-09T13:49:00.000-07:00

There are some computational problems in computer science which are known as NP complete problems. One famous example is the traveling salesman problem, where a map is handed to you and you try to find the shortest continuous path that visits a particular set of N cities. (Strictly speaking the NP-complete version is determining whether there exists a path shorter than a certain length). There are quite a few problems in this computational complexity class, and it turns out that if you manage to solve one of them, you can essentially solve them all. It is not known, as you make the problem bigger, whether the difficulty of solving these problems grows polynomial with the size of the problem (ex, with the size of N above) or exponentially with the size of the problem. In fact, this question is viewed as so important that there is a million dollars waiting at the Clay mathematics institute for anyone who can prove either that it is polynomial or it is not.

A few years ago, a group of physicists at MIT proposed that a quantum computer might be able to solve such NP complete problems in polynomial time (In fact, this would not win them the million dollars by the precise definition of the challenge set out by the Clay institute, but it is still extremely interesting). Their scheme was to find pose an NP-complete problem such that it is essentially equivalent to finding the ground state (lowest energy state) of an appropriately designed quantum system. Then the way they want to actually find this ground state in practice would be to deform the parameters of the system smoothly until it becomes a simple quantum system where the ground state is already known – then initialize the quantum system in this known ground state – then adiabatically (slowly) deform the system back to the system we are interested in. Now according to the so-called adiabatic theorem of quantum mechanics, if a system is put in its ground state and the system is deformed sufficiently slowly, it will always remain in its ground state. So at the end of the process, we are in the ground state of the system we want, and we have our solution.

Well, unfortunately, there is a catch. The catch is the words “sufficiently slowly”. The time scale that determines what “sufficiently slowly” means is the lowest energy of the first excited state at any point along the path between the initial and final state of the system. If this first excited state happens to come down to be exponentially close to the ground state, then one needs to deform the system exponentially slowly to stay in the ground state and the process will take an exponentially long time.

Since the proposal of this scheme many (if not most) of the people in my community have assumed that this catch is precisely what ruins this idea completely. Nonetheless, the idea has been floating around for quite a while now and the issue still had not been nailed down very well. This week at the INSTANS conference in Amsterdam, Boris Altshuler gave a pretty solid looking proof that this “catch” does indeed happen and such a computer would take exponentially long to finish. To do this, he focused on the the so-called 3-satisfiability (or 3-satisfaction) problem, which is one of the famous NP-complete problems. And since all the NP-problems are essentially equivalent to each other, this seems to kill the idea at last.

[ For the experts (and very briefly) the issue really boils down to whether there is any gap opened up by anticrossings between multiple low energy solutions. But since for NP problems the different low energy solutions are extremely different from each other, there is exponentially low tunneling between them, hence no gap opens up. ]

So it seems that the quantum computer will not be getting any satisfaction this way. No no no. Hey hey hey. That’s what I say. It can’t get no…

Pretty Town -- Overrun with Tourists

2009-07-05T11:32:00.000-07:00

My first visit to Oxford was in the summer of 1990. I was playing tourist that summer and after seeing the sights in London I took a train up to Oxford, hoping that it was far enough away from the big city that I’d be able to hitchhike from there up to Edinboro. I kept a journal of my travels that year and I happened to unearth it just recently. My comment on Oxford was “Pretty town – overrun with tourists” -- an accurate description for this time of year.

Admittedly, Oxford is a nice town to see, with all of its beautiful ancient architecture and historic sites. But now with the added draw of “Harry Potter Tourism” (as well as “Golden Compass Tourism”, “CS Lewis Tourism”, “JRR Tolkien Tourism” no, we don’t have hobbits, “Inspector Morse Tourism”, and the list goes on), it seems the natives (meaning me) can’t catch a quiet moment in the summer. It reminds me a bit of being in New York – but without the subway.

Anyway, on my visit in 1990, I only stayed in town for a mere few hours (during which I ran into no less than three other fellows students who were also playing tourist that summer – such was the density of American tourists at that time). Mainly my time here was spent trying to figure out how to get out of Oxford and on my way north. I remember asking around as to where a good place would be to hitch a ride. No one seemed to know. Eventually, some rather shabby looking homeless guy named Nick told me that I should walk to the ring-road north of the city and flag a lorry from there. My memory of the long walk to the ring road (carrying a very heavy pack) does not completely match up with the geography of the city. Probably my memory is faulty after almost 20 years. Or maybe the weight of the pack prevented me from seeing it correctly in the first place. Nonetheless, if I had followed Nick’s directions properly, the path would have taken me right past both the Physics department and Somerville College, my current homes.

On my long walk out of town, I remember stopping to watch a cricket game on the way. Probably this was at the pitch north of Somerville College on Woodstock road. The game absolutely mystified me then – and I understand only a tiny bit more about it now --- except to say that the games go on really forever and are even more boring than baseball (if such a thing is possible).

Finally, being completely exhausted from carrying my pack (which I later would reduce substantially by throwing “unnecessary” things out), I did catch a ride out of town from a random Oxonian – actually, a physicist as luck would have it. If I am not mistaken, this very physicist is now emeritus faculty at University of Sheffield, not so far from here. Hopefully soon I will have a chance to visit Sheffield and I intend to take him out to dinner to thank him for his kindness almost 20 years ago.

I did not return to Oxford until the fall of 2007.

Finally Fractional

2009-06-28T09:13:00.000-07:00

News flash from Lucca Italy. Eva Andrei (Rutgers) announced that finally she has seen fractional quantum Hall effect in graphene. I had heard a rumor that she had seen this and was just about ready to make it public, but I expected it to be rather ratty data. But it was exactly the opposite – the data was absolutely clean. Gaps seemed to be in the 20K range, more or less as expected (an order of magnitude bigger than in GaAs because of the dielectric constant). Kudos to her. People were starting to wonder why on earth no one had been able to do this. It is not that easy, but once you know a trick or two… pretty soon everyone will be able to do it. We witnessed an important scientific milestone. No question about it.

On hand for this announcement were two people who already have Nobel prizes for discoveries in quantum Hall physics: Klaus von Klitzing and Dan Tsui, two of the founding fathers of our field. Horst Stormer was invited to the conference too, but I gather he is trying to take the word “retirement” seriously. Actually, it is rather rare to have Dan and Klaus in the same room – because Dan hardly ever travels. Turns out he showed up to this conference because he has a son-in-law in Italy and wanted an excuse to visit. It was a real treat to listen to him give a talk though.

(PS: I'm not suggesting that this new discovery will win a Nobel prize. But it is a big step nonetheless)

When will I learn?

2009-06-28T08:51:00.000-07:00

When will I learn?

Once again, I find myself stuck in the Rome Fiumicino airport. Why? Because Alitalia has very few flights to London. So when my flight from Pisa was delayed (and perhaps I should have expected as much) and I missed my flight back to Heathrow, I was stuck for quite a while --- inconveniently long, but not really long enough to be able to go into Rome and look around. You would think, being that I found myself in this position less than three months ago, I might be a bit of a more savvy traveler by this time. Alas, I never learn.

Rule 1: Always take direct flights

Rule 2: If violating rule 1, do not take Alitalia.

Rule 3: You do not talk about fight club

***

Here's a simple multiple choice quiz. Which do you think took longer:

(a) Flying from Santa Barbara California home to Oxford on United Airlines with a layover in San Francisco, total distance 5425 miles

(b) Flying from Pisa Italy home to Oxford on Alitalia with a layover in Rome, total distance 774 miles

(c) They both took the same amount of time

I'll give you a hint. I am really annoyed with Alitalia this morning.

***

And while we are on the subject of great service from the airlines, I heard the following announcement in the airport:

“Attention please, if anyone needs a wheelchair, please come up to the front desk."

I couldn't make this stuff up.

Ahhh... Pasta!

2009-06-28T08:42:00.000-07:00

For years, one of the stops on my physics conference circuit was the Villa Gualino in Turino, a huge resort complex with views of the Alps when the smog of the industrial city cleared. The building had a simple cafeteria with a nice view which provided food, and a bar where we were served coffee between lectures, and beer at night. One of the most memorable components of visits to the Villa Gualino were the people who worked there. The young man at the bar frowned in disapproval if anyone ordered a cappuccino after 11am, and smiled approvingly if you drank espresso and wanted to watch the world cup on the bar TV. His girlfriend worked in the cafeteria, and spoke very little English. Every day at lunch and dinner there was a choice of meat or pasta: “Meat?… or Pasta?” was about the extent of her knowledge of the English language. If you chose the pasta she would smile and say “Ahhhhh!… Pasta!” as if your choice both made her happy and indicated that you were a person of high character as evidenced by your choice. Once I tried to ask her what kind of meat was on the menu. It took me quite a while to have my question understood, but when she did understand, she insisted it was elephant. I think this was the only animal name she knew in English. I had the pasta – which made her happy.

For some reason my field of physics has not had a meeting at the Villa Gualino in many years. But this week’s visit to the Villa Guinigi outside of Lucca Italy reminded me of the “Ahhhhh… Pasta” girl. Pasta was served for every meal except breakfast – and it was terrific – not the plain dried and boiled stuff you usually get – and much better even than the non-dried gourmet stuff you can sometimes get at the expensive supermarkets. I have no idea what they do to make the stuff have the perfect texture that it does – but I really want to find out (being that pasta still remains a staple of my diet, I might as well learn how to cook it right).

Don’t even get me started about how you can get a terrific bottle of wine in Italy for about 2 euro.

An Opinion on How Science Works

2009-06-17T10:14:00.000-07:00

I've always thought that there are really two types of people in the
productive physics community. There is a very very very small set of people who generate 95% of all the really meaningful progress. Then the rest of us are trying to pick up the pieces and help the leaders make progress by pushing here or there on some ideas that really come from the leaders anyway -- maybe extending this or examining that. It is not that we are being useless, in fact some of the stuff the rest of us do is pretty cool also, but we are more like support staff helping the truly brilliant.

In a bicycle racing team there are riders called "domestiques" who ride only for the sake of the overall team – they do nothing but keep up with the pack so they can cut the wind in front of the team leader and hand him water when he needs it. Their entire job in life is to assist the real leader - who then breaks away to win at the end. I think the vast majority of the theory community are more like domestiques. (Anyone who knows more about cycling can clarify.)

I tried out this analogy on Eva Silverstein, an official genius by the auspices of the MacArthur committee (Her typically modest comment on winning a MacArthur was “the whole thing was kind of ridiculous”). Anyway, Eva said, "yes, but…" as compared to biking the final result is not scripted. There is always a chance that you will be the one to make the next really big breakthrough. I guess that is what keeps it exciting for all of us.

Fraud 3

2009-06-14T05:22:00.001-07:00

I've already blogged about this before, so I will be brief. I just read the review of Plastic Fantastic in this Nature Article, by Martin Blume. Dr. Blume is pretty critical of the book. A few choice quotes from this review:
"Although some interviewees are mentioned, we do not learn which experts' views contributed the most."
"She tends to describe issues in black-and-white terms"
"It is unfortunate that Reich did not draw fairer conclusions, despite her hard work in reporting the facts."