Author Archives: Clifford

News From The Front, VI: Simultaneity

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aspen from gondolaI stopped the previous post rather abruptly (I had to do another task and then run some errands) without getting to tell you a little twist at the end of the story. Here it is.

Having chipped away at the thoughts that Strominger’s talk stirred in my head for several days last week, scribbling equations to check that all I was thinking was on the right track (and chatting a couple of times with Nick Halmagyi), I decided that it was all fitting together so nicely that the framework and my extensions of it just had to be true. There was that feeling that it was too nice to be wrong, and it passed all the obvious checks I could think of. There were two independent consistency checks everything had to pass (using my way of formulating things) and they gave exactly the right results as required by the general setup, with no room for maneuver.

When that happens so nicely, usually at that point in thinking about a physics problem, a thought occurs to me. If I’m playing with a good idea and everything is working so well, then there’s at least 200 other people in the field who probably are also playing with it, and 199 of them have way more time than I do to think it through and write it up before I can. One should not really worry about these things in an ideal world, but I’d be lying to you if I said it did not come up as a concern from time to time. I’ve a history of having my thunder stolen out from under me several times in the field (and not always accidentally), so I’m a bit gun shy.

Anyway, I started writing a draft of the paper on Thursday the way I usually do: I write […] Click to continue reading this post →

News From The Front, V: Microscopic Weekend Diversions

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I’ve been spending the day so far as an administrator, and not a researcher, since I have to present the results of two committees’ deliberations at one of the big annual organizational meetings tomorrow here at the Aspen Center for Physics. So I’ve been gathering and arranging data in a presentable form. Enough. I will take a break and blog a tiny bit before turning to a truly riveting task – reviewing an introductory physics textbook for a publisher… (Sigh…it is not so easy to escape these things out of semester time.)

I had big plans to do a hike each day on the weekend, but physics intervened. I should explain a bit more. Earlier last week I eventually got around to following Nick’s suggestion from an earlier post to take a look at Andy Strominger’s Strings 2007 talk entitled “Search for the Holographic Dual of N Heterotic Strings”. It was the usual nice Strominger talk, where he motivates the physics very well, and presents interesting and clear D-branesthoughts on the problem in hand. I shall try to say a bit more about what it is about later on, but the general gist of it is that it is to do with understanding certain types of four dimensional black hole in string theory. As you may know, one of the extraordinarily successful results in string theory in the last decade (and slightly more) has been that we can understand one of the most central results of semi-classical quantum gravity -that they have an entropy and behave like thermodynamical objects (the work of Bekenstein and of Hawking from the early 70s)- in precise terms in the full theory of quantum gravity that string theory appears to present us with. This started with the work of Strominger and Vafa in 1996, that showed how to describe a large class of black holes as essentially made of extended objects called D-branes (about which I’ve spoken at length earlier1).

Just to fill in the gaps roughly: Hawking’s result that black holes can radiate as thermodynamical objects comes from taking Einstein’s theory of General Relativity and combining it with Quantum Mechanics in a partial way. He could not really do much better since there was no proper quantum theory of gravity at the time, but even in […] Click to continue reading this post →

One!

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first anniversary sketchOne year ago today, I did the Welcome post on this blog. It is Asymptotia’s first birthday anniversary!

It has been a very enjoyable year of blogging here, and sharing the company of so many of you who visit occasionally or regularly to read, and perhaps share a thought, joke, an idea, or an anecdote. This sort of blog, with its wide (and perhaps odd) selection of topics, from the fun to the serious, the trivial to the profound (well, I’m still working up to a profound post!), the light to the heavy, and the local to the global, is not to everyone’s tastes, and that suits me fine.

It’s just been great to have the freedom to pick and choose topics as I please, knowing that you in turn will come and go as you please and use the scroll bar as much as you see fit. It’s an excellent arrangement.

If you have been coming back for more, then it must suit you to some extent too, so that’s great. Thanks for your readership, participation, and support. In case you’ve […] Click to continue reading this post →

More Than A Hint Of The Old Days, II

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A strange but satisfying aspect of my time here (I’m at the Aspen Center for Physics, recall) has been the fact that due to some odd serendipity, there’s a ton of people from the “old days”. Which ones? My Princeton years, in the early 90s, as a postdoc at the Institute for Advanced Study (and later at Princeton University). These are not all people doing what I do, but in a wide range of fields such as high energy physics, astrophysics, condensed matter physics. Several of us were postdocs together. I’ve been chatting with people I’ve not seen for a while, sometimes not since those days, or they are people I met back then, and with whom I have a pool of shared memories from those days. So it has put me in mind of those times somewhat.

A quick example. Soon after I arrived last week, I was walking along, chatting with Petr Horava (Berkeley) about various things, and we got on to reminiscing a bit about our time together as postdocs in Princeton. And then minutes later, as though conjured from the very substance of our conversation, who should walk by but one of the Gods/Legends of the field (then and now), Princeton’s Alexander Polyakov. He walked by in exactly the same sort of way he would back then, either coming from or going to a walk along the river or canal, perhaps to give us a lecture. Petr and I looked at each other, and continued our walk and talk.

The great news for me last week was that Polyakov then gave a talk. I’ll admit to being a big fan of his physics. When he gives a talk nearby, I show up, no matter how confused I might end up at the end. There’s going to be good stuff in there – it’s only a matter of time before it sorts itself out in your head. Often years. Decades. Several of us sat in on his graduate class back in Princeton in the early 90s just to try to catch the pearls of wisdom which we’d pick up as he lectured on….. Well, I’ve no idea to this day what the class was really about. He would show up (probably fresh from a walk), with no notes or anything, and just pick up a piece of chalk, stare out the window for a few seconds, and then start writing stuff. Essentially, he was randomly jumping around the subject matter in his widely under-read book “Gauge Fields and Strings”. He was all over the book. It was not always a simple and coherent path through the subject matter, and it seemed that he was largely exploring whatever took his mood in the moment, but I suspect that was largely my ignorant young mind’s impression.

Polyakov in Aspen
A. M. Polyakov in the middle of giving what for me was an excellent and intriguing seminar at the Aspen Center for Physics. Click for larger view.

Sadly, it is the type of course that these days would score close to zero in most […] Click to continue reading this post →

A bit of Sex with your Higgs

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Remember that Nick Evans (physicist at Southampton University) wrote a mystery/thriller (set in and around the exciting particle physics at the LHC at CERN) that you can download from his website? It’s called “The Newtonian Legacy”, in case you were not aware of it. It was notable for (among other things such as the pedagogical explanations, in a fictional setting, of the particle physics such as the Higgs particle being discussed a lot in the press of late – see related articles at bottom of the post) not being shy to blow the covers off the remarkably exciting life of sex and drugs we high energy physicists lead1.

Well, having got some sex and murder into the Times Higher Education Supplement[…] Click to continue reading this post →

Happy Higgs Hunters

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There’s another article about the search for the Higgs particle, the recent rumour kerfuffle involving the Tevatron, and the upcoming LHC experiment at CERN. (See related articles at bottom of this post.) This time it is in the New York Times and it is by Dennis Overbye. There’s a bit of discussion about how the fact that there are physicists blogging about these topics tends to amplify some things that might not (or should not?) get amplified otherwise. I’ve nothing really to add to the discussion, except to say that it is far better written -showing better understanding of the science, and the scientific implications of the rumour- than the article in Slate, by James Owen Weatherall, that I criticizedin an earlier post . Ironically, Weatherall is a recently trained (in particle physics) scientist. Go figure. To be fair, Overbye has the benefit of a long wait for the rumours to die down and reality checks to be done (and lots of good journalistic experience under his belt, and maybe a bit more seniority to fight with his editors, if that was part of the issue for the Weatherall article), so we all hope Weatherall will get better with time. (Above right: A random collision event I grabbed from the DZero experiment.)

See some other posts on this article here (starting with Gordon Watts laying down a […] Click to continue reading this post →

DNA on Sunset

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dna film festival posterAs you may know from some of my earlier writings, I dream of the day when science is just as much a part of the typical person’s conversation as, say, the latest antics of Paris Hilton1. This is not just because I happen to be a scientist, but because we’re increasingly becoming less of a democratic society when on the one hand there are more and more issues dominating our lives that are basically science issues (energy sources, aids and cancer research, stem cells, global warming, air and water quality, food safety, etc) and on the other hand science is still largely feared, and left as the province of the “geek”, the “nerd”, and all those other select few people in business and politics who are essentially controlling our everyday lives by being handed the scientific reins of society. So, as part of reversing that trend and restoring equal opportunity in the broadest sense, I like to think that we can have increased comfort with science concepts and images infiltrating and enriching our everyday language.

I was delighted therefore to see (a couple of months ago now) the poster campaign of the Los Angeles Film Festival for 2007. It is a perfect example from that society that lives in my dream. It unselfconsciously has encapsulated the two big themes they wanted to convey quite marvellously. On the one hand, there’s no doubt that it is about film (you don’t even need the rest of the poster to tell you this) as there is the film reel, and on the other hand, they want to remind you without a doubt that this is a land of film, and they did this with a simple slogan that put to rest any doubts about their intent in twisting the reel to bring out a double helix structure: “It’s in our DNA”. Excellent. I’d like to shake the hand of the designer(s) who came up with this. (Read a bit about the DNA molecule -which contains our biology’s “blueprint”- and its double helix structure at the Nobel Prize site.)

Here is the detail from one of their posters that I snipped from their website: […] Click to continue reading this post →

The Man of Tomorrow?

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[Updated with a bit of video!]

Earlier this week I went for a walk with Nick Halmagyi to chat about physics, and since he had not been down to the meadows and gardens over by the neighbouring Aspen Institute, we wandered down that way. It was just after lunchtime, and a very hot day, and as we got near the Institute, we diverted away from physics so that I could tell him briefly what the significance of the Aspen Institute is. I explained that it was an important “think tank”, host to thinkers in the humanities, sciences, and diplomats, presidents, ex-presidents, and other dignitaries, who come and think great thoughts about the problems of the world. Well, let me use their own words from their website:

The Aspen Institute, founded in 1950, is an international nonprofit organization dedicated to fostering enlightened leadership and open-minded dialogue.

As an example, I explained, it is probably the sort of place that Al Gore might have come to in order to think deeply about the environmental issues he champions. It is nice that the Aspen Institute is right next to the Aspen Center for Physics, and the two organizations, while now independent (but the Center actually grew out of the Institute, see here) sometimes work together on various matters including public outreach. The public lecture I gave here last year as part of the Heinz Pagels Memorial Lecture series (see e.g. here and here), for example, was actually over in the Paepke auditorium, one of their buildings.

We approached the main grounds of the Institute, near their residence buildings, and were greeted by a most frustrating -and ironic- sight. Their sprinkler system was fully on, spraying water unnecessarily into the air and onto the asphalted walks, with some making it onto their lawns, where even there it would mostly evaporate (in addition to aiding the hot sun in scorching the grass somewhat). For once, I did not have my camera and so cannot share this horrible sight with you. For a moment it was as though I was back in LA, but this was Aspen, where everyone talks about the environment. Then I remembered – everyone talks about the environment. At the same time, there are more and more SUVs every time I come here (rental companies even try to force SUVs on you when you try to rent a regular compact car – did you read my story of that last year?), more and more land seems to be cleared to build ever-larger houses, and so forth. On the other hand, bicycle use is very high here, there’s an excellent free bus system, an enforced reduction of individual car access to the Maroon Bells wilderness area, and I imagine several other worthy environmental efforts that I have not seen are being made. So it is a tale of two communities and mind sets. It’s complicated, as with any populate. But you’d have thought the Aspen Institute would be “fostering enlightened leadership” by not watering their lawns and (sidewalks) with vast amounts of water at the maximally worst time of day to do so in terms of effectiveness. (Frankly, given the environmental disaster most lawns are, one could go further and hope that in the spirit of leadership, they’d turn more of their expanse of lawns into other use, perhaps expanding the excellent wildflower garden they have in one corner, or letting more of the surrounding meadows repopulate the grounds. It could be rather beautiful.)

wild flower gardens at aspen institute

Anyway, we shook our heads at the irony of the sight and we wandered off toward the river, continuing our chat about matters in other dimensions (no, really). The next day I came back at that same time to check the sprinklers again (with camera), since such systems are often on timers, but had it rained very heavily the previous night and so -happily- it did not seem that the sprinklers had been used.

On Wednesday I returned once more. The sun was overhead and strong again (not as much as Monday) and the main system was not on. But once again I noticed signs of watering, and saw a smaller component of the lawn being watered by a hose-driven system. I now think that it might be that they were sprinkling (well, gushing) on Monday (and partly on Wednesday) in the mistaken belief that pouring water (and into the air, where it rapidly evaporates) on the lawn while the sun is baking it will somehow help, and they did it on an ad hoc basis, but I can’t be sure. Either way, it is a terrible waste of water resource by an organization that is committed to leadership in matters of importance, such as the environment.

Then I noticed that many people wearing name badges were heading from the Institute toward the direction of the auditorium and the Aspen Music tent. This fit with the next deliciously ironic thing: Al Gore was going to be talking! He’d been at the Aspen Institute (I’d no idea of his presence or the event until a radio announcement on Wednesday morning), and the sprinkler matter, this was remarkable. Convenient, one might say.

It turned out that it was not taking place in the Paepke auditorium, as I thought it […] Click to continue reading this post →

All In A Day’s Work

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Difficult to say what a typical day is at the Aspen Center for Physics. It probably varies a lot from person to person, since many people are here for different reasons, and with different goals. There’s a lot of sitting and thinking, and walking and thinking. There’s a lot of chatting in corridors, and at blackboards. There’s quite a buzz of productivity during the middle of the day. On some days, there might be a couple of seminars, where someone presents finished work or work in progress. Here’s Robbert Dijkgraaf (University of Amsterdam) leading a discussion of some of his recent work today:

Robbert Dijkgraaf at Aspen

In addition to some seminars, my day was filled up a bit more with some administration. I’m on a couple of committees that helps keep things ticking along […] Click to continue reading this post →

Blue Intensity

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Dan Flavin sculpture

This is another of the incredibly striking Dan Flavin sculptures that I saw at the retrospective at LACMA (the Los Angeles County Museum of Art) earlier this month.

The sheer blueness of it was particularly striking, I have to say. It was intense. I left the colours from neighbouring pieces at the edges of the image, since I think this helped set the blue in your visual field before you then walk into the corridor and immerse yourself in the blue. I think that helped enhance the blue, but I’m not sure. It was interesting to note that the blue was nowhere near as powerful when starting at the […] Click to continue reading this post →

Strings 2007: Share the Memories

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trees near the aspen center for physicsA big chunk of yesterday (recall, I’m visiting at the Aspen Center for Physics) was spent chatting with old friends in the field I have not seen in a while, including going for a walk or two in the local surrounds with colleagues, discussing some of the physics issues of the day.

One of the things that comes up a lot with everyone I spoke to (and met at lunch, and in corridors and so forth) was Strings 2007, the big annual meeting that was held in Madrid last month (blog post here). It comes up in the form of people asking each other things like: “were you at Strings?”, “what did you think of Strings?”, “what were your favourite talks?”, “is there any interesting gossip about…?” (where the latter is not necessarily directly about physics).

So it occurred to me that some of those conversations and responses might be useful to workers in the field. Of course, you can just sit and work your way through the entire collection of online talks, a good thing to do. But it’s interesting to hear from others what talks they liked, and why, just as we do (and maybe have done) over tea and coffee in lounges all over the world after someone returns from a meeting. Often, this is where we hear of some excellent work by the less famous speakers (or even by someone who did not talk at all), etc.

So I’ll kick off. Although I was not there, and have yet to start a serious assault on […] Click to continue reading this post →

Twenty Thousand Bikes

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velib bike from parisSo, has anyone who reads the blog used the new Velib system in Paris yet? A new layer of public transport has been rolled out (yes, I know) onto the streets of Paris, as of last Sunday (July 15th). The Bicycle. A publicly funded scheme (familiar to some from elsewhere, such as Lyon and Amsterdam (?), if memory serves) called “Velib” where there are special bike racks all over the city. One of the (charmingly European-looking) bikes is pictured on the right. From a BBC story by Emma-Jane Kirby:

The local authority in Paris has deposited 20,000 heavy-duty bicycles in 750 or so special racks around the city and anyone who wants one simply swipes his or her ordinary travel card and pedals off wherever they want to go.

The bike does not have to be returned to the same pick-up point – you can take a bike from a rack near the Eiffel Tower, cycle to the Pantheon and leave it in the nearest Velib stand there.

This sounds great, from my point of view, you’ll not be surprised to learn! I’m finding it hard to see a downside here at all. A bit more:

The Velib scheme is aimed at people who are making short journeys.

The first half hour of pedalling time is absolutely free but, if you fail to return the bike after 30 minutes, you get charged an extra euro and the penalties go up the later you are.

(So European… penalties. They could not find another, more positive word?)

The Velib website is here. And of course it is only in French. What did you expect? (Actually, it is rather entertaining to read, all the same, since it is mostly easy-to-guess French, and knowing the context helps.)

I can’t see what’s stopping such a system from being introduced in cities in America. I think that we should start with….. Los Angeles, of course! It is one of the cities that […] Click to continue reading this post →