Category Archives: research

Uses For Strings?

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viscosity_scatterThere were a couple of string theory stories in New Scientist last week. I forgot to mention them earlier. One is entitled “What string theory is really good for”, by Jessica Griggs. The other is entitled “Why cats fail to grasp string theory”, by Ewen Callaway.

Well, since cats are involved, of course I’m going to start with an extract from the second (even though it is obvious that the cats are deliberately skewing the results):

[…] Osthaus’s team attached fish or biscuit treats to one end of a string. A plastic screen with a small gap at the bottom separated cats from their reward, requiring the felines to tug on the string to get the treat.

With a single string attached to the food, most cats learned to paw at the string to get a snack. But when Osthaus’ team introduced a second piece of string, […]

Well, that was to pique your interest. You’ll have to go off to the source article to get to grips of this second piece of stringy research. The first article? It’s a discussion of […] Click to continue reading this post →

An Odd Time

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watchWell, it was an unusual day here in Aspen. It was a day with lots of talks. Six of them, I think. There were four workshop talks scheduled for the morning, each of half an hour I think. Also got into a discussion before the sessions began, helping to explain how gauge/gravity duals work to a condensed matter colleague. I checked a voicemail message (only a relatively limited set of people have my number and so I figured it was a call to which I’d want to respond) and, despite the fact that I’m in retreat mode and would normally ignore it, returned the call. It was an office at USC wanting to put me in touch with a journalist who needed help. From Esquire. No, it is not what you think. I suggested they can could call me at 13:05, and at 10:30 went to the talks.

Somehow, successive speakers kept running over time due to lots of (actually, pretty interesting) interruptions and discussions, so I did not mind that we got to 12:50, and my talk, which was scheduled for 12:00-12:30, had not happened yet. With […] Click to continue reading this post →

Ink Time…

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ink_break_aspenAh, time to relax a bit after a somewhat busy last couple of days glued to the notebook and computer. The results? (1) A hasty colloquium to an audience of mixed expertise to try to get across a sense of why some of us are excited about various applications of string theory to a diverse range of physics including ongoing experiments in nuclear physics and condensed matter physics (the person who was going to do it was a bit ill apparently so I stepped in with some hastily prepared slides… a bit messy but hopefully some use)… (2) Two papers with my student Tameem on applications of string theory techniques to superconductivity (one will appear on the ArXiv in about 20 minutes if you are interested [update: it is here.])… (3) Notes for a talk I’ll give on Thursday about said new results… (4) Several discussions with and ideas sent to some documentary film makers about some new TV shows coming up – Season 4 of The Universe! Seems I’ll get involved in some of them (stay tuned)…

So this morning I went to sit and cool down a bit at a cafe I like to visit a lot when in Aspen. Ink Coffee. Ok, I see that I did not yet mention I was in Aspen. Have been for […] Click to continue reading this post →

LHC News

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lhc_and_mont_blancJester at Resonaances reports on a talk by Jörg Wenninger about the progress at the Large Hadron Collider (LHC).

There’s information about the repairs, more thoughts about the accident last year, and somewhat frightening news about issues of quality control on some of the manufacturing of crucial parts that may haunt the entire project for some time to come. […] Click to continue reading this post →

Hawking Talking, and More

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Gosh, time flies!

I almost did not get to announce this before it was upon us. Tomorrow and the day after combine into a notable event in the College Commons series here at USC. Some of us have been working on this for quite a while. On Tuesday we have Stephen Hawking giving a big public lecture entitled “Out of a Black Hole”. Here’s the announcement. Note that general tickets for seats in Bovard Auditorium all went within hours of us releasing the tickets several weeks ago, but there is room in the two spill rooms that we have set up where there will be screens relaying the talk. Make a bit of an event of it and go with friends! [Update: I forgot to mention that we had a competition in local high schools and also at USC where the prize was to ask Stephen Hawking a question. People submitted questions over the last few weeks and we selected some of the best. There will be three undergraduates and three high school students coming up from the audience (we’ve a lot of high school students visiting us for the talk) to ask him a question each at the end. Should be fun.]

The day after, there will be a related event. Some of us from the physics department […] Click to continue reading this post →

24 – Physics Edition (Day Two)

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February 14th 2009: Valentine's Day.

9:00pm – 10:00pm

…Must be here somewhere. Maybe inside the monolith? No. Seems it is not inside the jumbo suitcase, which I have not used since Aspen last year anyway, and I’m pretty sure that I did not use it on that trip. Where can it be? That box over there? No. (But I found that bag of plastic book covers that I’ve been using sparingly since I left Preston for London in 1986. Excellent. The things I don’t throw away…) Well, never mind, would be silly to make myself miss a flight over an inflatable pillow that I have not seen in over a year. If I play my cards right, I won’t need it anyway….

9:10pm Now to put all those things I set aside earlier into my trusty little day trip bag. Change of clothes, electric shaver, toothbrush and so forth. I suppose I will bring the laptop. And some bits of equipment that might be useful as backup for Peter’s plan. Or whatever. You never know. Yes, I throw in my copy of Accordion Crimes. Almost finished it, and if I do, would be good to get another Annie Proulx to continue enjoying her wonderful writing…

9:17pm Will someone tell me how I managed to be perfectly on time, and then fritter away some of it to make sure I’m slightly panicky late again? Sigh. I was more or less ready at 9:00, when I should have left. Despite all the events of the previous 24 hours ((Day One) – Valentine’s Day Diary – Available on DVD) I got everything together on time, and wouldn’t it be rich if I missed the flight?

9:23pm I leave finally, using the batcave, slowing to check that entrance closes, then vanish into the night toward the airport. Saturday night late in LA. Surely everyone is out having awkward dates? The roads will be clear this late on a Saturday night, right? I can make my 10:07 check-in cutoff, I’m sure.

9:33pm. 101 Freeway. Full of traffic. Don’t you people have dates you’re supposed to be on!!?? This is my road! My! Road! […] Click to continue reading this post →

Once More, With Feeling?

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Well, the good news is that there’s a definite schedule in mind for the restart of the Large Hadron Collider (LHC). (See related posts below for more.) We can resume licking our chops in anticipation of exciting new physics of various sorts! I learned about this from US LHC Blogs with posts by Steve and Peter. Some key things (apparently from a widely circulated email that heralds an official press release to follow soon) are as follows. First, Steve’s synopsis of the schedule: […] Click to continue reading this post →

Another Approach?

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No, it’s not my solution to things (you know, when patient, tiring, endless, circular discussion and explaining that it is work in progress does nothing to stop the whining of those who’ve made up their mind in advance…) but it certainly makes me laugh out loud! Enjoy:

arguing with a string theorist by abstruse goose

(Click to go to larger version.)

Taken from Abstruse Goose, which is hilarious!* This follows on nicely from […] Click to continue reading this post →

So What Is String Theory, Anyway?

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The usual answer you’ll get from the person on the street (as it were) includes lots of nice words about wiggling strings that look like particles, and so forth, and that’s fine. However, the [informed] next level answer, when you’ve worked enough in the field, is that we don’t know. I’ve told you why (at least in part) in previous posts and so I’ll let you read them. We’re still working on it.

While we work, we’ve learned that it is a quite marvellous thing (from the bits of it we’ve come to grips with) that is teaching us a lot about all kinds of physics, and mathematics too. Some of this may be good for describing things about Nature, and we’re still working out lots of that (although see some of the exciting things I’ve been talking about in my previous post and the links therein).

So what do we put on the T-shirt? (You know, the analogue of Maxwell’s equations for electromagnetism – light, etc – that every physics undergrad likes to have on their T-shirt). Well, we don’t know yet.

polchinski what is string theory

But that’s all my opinion. Every now and again it is good to hear from one of the masters about what they think of string theory*, and what it is and so forth. Happily, Joe Polchinski has been known to agree to stand up and give an exposition on this […] Click to continue reading this post →

Preparation

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Yes, I’ve been a bit quiet of late, I know. I’ve so many things on, both professional and personal that it sometimes keeps me occupied from when I wake up just before sunrise right through to falling asleep a bit after midnight. And yes I know that means I’ve been not getting the traditional full nights of sleep, but if my body insists on getting up at 5:30am, who am I to resist? I thought it was due to jetlag from the trip a couple of weeks ago, but it seems to have taken. I don’t mind too much since watching the light change as the sun rises is a marvellous way to start the day.

clifford johnson preparing slides at the boardAmong the things I’m up to (yesterday and today so far) is a strip-down-and-redesign of a short talk for an exciting symposium that is coming up in a few weeks in Chicago. The American Association for the Advancement of Science is having their big annual shindig there (apparently the biggest science conference in the world) and there will be a number of addresses, plenary talks, and keynote speakers and the like (including Al Gore, by the way), and also several sessions of symposia and other presentations on various topics.

While slightly annoyed at the fact that one major day of the conference is on Valentine’s day (which means I’ll have to be out of town on just the day that maybe, just maybe, on the off-chance, you know – if the universe sneezes or something, somebody might want me to be their Valentine…*), I was looking at that day’s schedule and it caught my eye that there’ll be a session (with several presenters) entitled “The Science of Kissing”, and three hours long, no less:

[…] Click to continue reading this post →

Weinberg on BCS

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For some reason I don’t understand, I occasionally get a copy of some random (as far as I can tell) issue the International Journal of Modern Physics A in the post. It just arrives. The people at World Scientific are presumably hoping I’ll get hooked by it and take out a personal subscription or something. Not sure. Well, it has not happened yet (just as it did not with the unsolicited regular arrivals of Angeleno a while back). But you never know.

Anyway, before putting the one that arrived recently on to my shelf (I can’t easily throw things like that away… it’s a problem, I know) I glanced through the contents to see if there were clues as to why this one was sent to me. I found no obvious ones, but the very first article caught my eye. It was a rather good essay by Steven Weinberg (1979 Nobel Prize in Physics) on BCS (J Bardeen, L N Cooper and J R Schrieffer – No, nothing to do with College Football’s BCS.) theory of superconductivity and the importance of the idea of spontaneously broken symmetry in condensed matter physics and then in particle physics (see last year’s Physics Nobel, by the way). I thought I’d point it out to you, since it is rather nicely written and very instructive (whether or not you’re already familiar with the phenomenon/idea).

He begins with some overstatement, however. He expounds upon the difference between particle physicists and condensed matter physicists and although it is amusingly written in parts (I assume intentionally) he really over-eggs the pudding, in my opinion. Look at this: […] Click to continue reading this post →

Thermodynamics and Gravity

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ads_ballI noticed that Robert Helling shared some thoughts about thermodynamics and gravity today on his blog. He is understandably confused about several aspects of the issue, especially when applied to cosmological issues. (What is the entropy of our universe? Does the Second Law really apply? Does equilibrium thermodynamics even apply here?)

I’ve nothing remarkable to add to the discussion at this time except to note that a blanket statement that thermodynamics and gravity don’t seem to go together (which I don’t think he’s strongly saying) is not one I’d make, since we have a major class of working counterexamples.

The context is the gauge/gravity duals I’ve talked about here a lot, starting with AdS/CFT and beyond. There we know that the gravitational systems are essentially able to display the more garden variety thermodynamics by being immersed in the (regulating-box-like) anti-De Sitter type backgrounds. Then we see that black holes […] Click to continue reading this post →

Southern California Strings Seminar

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Takuya Okuda talking at the SCSS at UCLA, Dec. 2007Takuya Okuda talking about Wilson Loops at the SCSS, UCLA, Dec. 2007. Click to enlarge.

The next regional string meeting is a two-day one at USC, this Monday and Tuesday. It’s going to be full of interesting talks and conversations, as usual. Please encourage your graduate students to come, especially, since special effort is made to make sure that each talk begins with a pedagogical portion to help non-experts in that subfield navigate and see the motivation.

The speakers are: […] Click to continue reading this post →