[Note: Originally posted on CV on 4th November 2005. 25 comments on it here. Feel free to add new ones here.] ___________________________________________________________________________________ [Warning! This is an unusually technical post.] Ok, so last time, I told you a bit about the motivations for what I’ve been up to. Now I want … Click to continue reading this post
[Note: Originally posted on CV on 31st October 2005. 31 comments on it here. Feel free to add new ones here.] ___________________________________________________________________________________ Well, I suddenly have 45 extra minutes on my hands as I was supposed to be at a very interesting two hour lunch meeting which I’ve now missed. … Click to continue reading this post
[Note: Originally posted on CV on 3rd October 2005. 65 comments on it here. Feel free to add new ones here.] ___________________________________________________________________________________ Below is a snapshot of a computation I was working on earlier this Summer. Will explain later. Spoke about it at the Southern California Strings Seminar. I’m curious … Click to continue reading this post
The next three posts are repeats of posts I did on CV in 2005. They were the first three in the series entitled “News From The Front”, and their subject matter partly lay the groundwork for a post on some new results that I hope to write soon. Enjoy! -cvj
The next regional string meeting is a two-day one at Caltech, this Friday and Saturday, organized by Joseph Marsano. 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
The next regional string meeting is a one-day one at UCLA, organized by Michael Gutperle and Per Kraus. 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. (Photo: Michael Gutperle talking at the first SCSS at USC, Sept. 2005; click for larger view.)
The speakers are: […] Click to continue reading this post
[Post reconstructed after 25.10.07 hack]:
Two Thursdays ago I went up to Santa Barbara to give a seminar. I had a great time, and it reminded me why it can be so much fun to go somewhere and visit for even a short time and do that. I got to catch up with several old friends, including Santa Barbara itself, where I lived for a number of years in the 90’s when I was a postdoc. I spent time chatting with the various people there before (at lunch) and after (individually) the seminar, learning about some of the research they’re doing, and also talking about other matters physics-wise and gossip-wise. I wish I’d had more time to talk since I did not get to talk to everyone I wanted to talk to, and not at as much length as I would have liked. (This was partly due to the fact that I spent the morning in my hotel room writing some of the slides for my talk. – I had a presentation the day before to focus on, along with a departmental visitor to host, and the day before I was also occupied. Don’t ask about any earlier than that – I never prepare new material that much in advance. Not because I don’t want to, but it just never happens… if I have more than a day or two, I will find that there’s other stuff I have to do.)
Anyway, a good time was had by all (I think). I can even post a picture of some of us at dinner in the evening after the talk. (Will update later with that, since it was downloaded to computer that’s not here.) We went to an old haunt of mine in downtown Santa Barbara – Roy’s. I’m pleased and surprised that it is still there and going strong, since it is the sort of highly individual restaurant that – since it is also reasonably priced – you’d expect to vanish from such a high value spot in town.
What was I talking about? Well, with three students (Tameem Albash, Veselin Filev, and Arnab Kundu), I’ve been involved in some fun work on some of the physics concerning […] Click to continue reading this post
Gosh, a thoughtfully-written general level (more or less) article on some of the general outcomes of string theory research! It’s written by Matthew Chalmers, and is in the Sept. ’07 edition of Physics World*. The article can be read online here, and downloadable pdf is here. The graphic on the right came with the article. I don’t fully understand what it is, but the title, like that of the article, is “stringscape”… Look, let’s not over-think this cvj – it’s a pretty decoration.
I’ve done a quick read of it (should re-read more carefully later on – it will no doubt have some emphases with which I disagree somewhat**) and I’d say it is very much worth reading. While not a perfect summary (what is?), compared to a lot that’s been out there, you’ll find it rather more informed, less sensational, (refreshingly unpoisoned by various prejudices, such as the presentations of Smolin and Woit – see numerous earlier discussions in the “More Scenes from the Storm in a Teacup” series of posts, and others), and unafraid to go to some length to unpack the issues somewhat carefully.
Very importantly, it contains numerous quotes from various respected researchers in […] Click to continue reading this post
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Hot, hot, hot, hot stuff
hot, hot, hot
hot, hot, hot, hot stuff
hot, hot, hot
– from “Hot Stuff”, by Donna Summer (1979). I refer to not only the physics but the c. 100 oF temperatures we’ve been having here every day recently.
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On my way back from the conference, I spotted this book (left) last Saturday in Foyles (the booksellers) in London 1. 
It is a collection of reprints of a lot of the papers forming the foundations of the physics of the quark-gluon plasma (QGP) idea, going back the early to mid 1970s with such papers as Collins and Perry (Gosh, I had no idea Malcolm was one of the early workers on this idea. He’s much more thought of as associated with black holes, gravity, strings and so forth, ideas which – ironically – have recently turned out to be relevant to the discussions of the physics too. See my recent post, and there are also various popular articles to be found2).
Putting aside the usual ridiculous price that Springer Elsevier charges for books, I found myself in two minds about this book, in view of the surprises being uncovered about the properties of this remarkable state of matter at the RHIC experiment. Is this collection of early papers a useful working tool, or is it now just of historical interest, since many of the basic expectations about the properties of the plasma seem now to be incorrect?
Well, after a bit of thought, I decided that the latter view would be way too hasty. First and foremost, on a general level, even if some of the computations in some papers were done in the “wrong” light (it’s a strongly coupled liquid that flows, not a weakly coupled gas of quarks and gluons), much of their content will still be useful in many ways – good and correct calculations last for all time, it is the sense of the words decorating them that may crumble over time. More specifically, one can worry about whether there were assumptions (and approximations based on those) that went into the computations that will render […] Click to continue reading this post
To save some of you the trouble of wading though my long post on the Newton Institute conference and the background to aspects of the physics, I’ll point here to the archive of online talks, which are here, and more are being added regularly. There are also talks from the … Click to continue reading this post
So the conference here at the Newton Institute in Cambridge is simply marvellous. I’m so glad I came, and so happy that I was invited to attend and make a contribution to it by giving a talk and having discussions. It’s a rather splendid combination of experimentalists, phenomenologists, and various hardcore theorists of various sorts, and there are ideas just flying around and bouncing off the walls. The title is “Exploring QCD: Deconfinement, Extreme Environments and Holography”, (it’s organized by Nick Evans, Simon Hands, and Mike Teper) and the focus is very much the fascinating nuclear physics of heavy ion collisions at the RHIC experiment at Brookhaven, and the experiments to come on heavy ion collisions at the LHC at CERN. The latter is an aspect of the physics to be done at the LHC that you don’t hear about much because it is sidestepped in favour of discussions about the Higgs, origin of mass, supersymmetry, theories of everything – such as strings, microscopic black holes, extra dimensions and all that other good stuff. (See earlier discussions here, here and here.)
Well, the great thing is that there’s been plenty of discussion of black holes, extra dimensions, strings, and so forth at the conference because of a great deal of promise of its relevance to nuclear physics. It’s been right alongside the discussion of experimental results, and other theoretical approaches such as work on computer simulations of aspects of QCD (“lattice QCD”) and studies involving other techniques. There’s very much a spirit of open-minded exchange among all the various parties […] Click to continue reading this post
I’ve just noticed that Jacques Distler will be blogging from Strings 2007 (his first post is here). Excellent! I hope that others will be too. If you learn of anyone else who will be blogging from the conference (either physics content or other aspects of the event), do let me … Click to continue reading this post
The main annual conference in my main field of interest starts today. Strings 2007 is in Madrid, and runs all week. The website is here (while there, have a play with the front page image of the Goya painting – quite entertaining). They promise to update the schedule/speakers page with scans of slides, and video, so you’ll be able to keep track of some of the new developments online. There’s no system for doing this live, or asking questions remotely, so if you want to quiz Ed Witten about his new 83-page monster paper on three dimensional gravity that came out yesterday (just in time for the conference!), or feel the buzz of event-anticipation whenever Witten talks about huge new sets of results, you’ll still have to show up in person.
Why am I not there? Well, it would be nice, but there are lots of reasons I’m not going […] Click to continue reading this post
Not long after I told you about the TASI school and the excellent online lecture resource they were rapidly building, I heard* about a school in Utah that might be of interest, especially if you’re interested in the fruitful interface between mathematics […] Click to continue reading this post
Writing in Slate magazine, James Owen Weatherall seems a little confused about how particle physics works. Based on a rumour that there’s a new and significant signal seen at the DZero detector at the Tevatron at Fermilab (Illinois), one of the article’s titles is “Why the rumored discovery of the Higgs Boson is bad news for particle physicsâ€. Supposedly, the big new machine, the Large Hadron Collider (LHC – see more about it here, and what physicists are hoping for from it), about to switch on later this year, would have nothing to do, and would be a waste of billions of dollars. You can read about the original rumour here.) (Above right: A random collision event I grabbed from the DZero experiment.)
Well, this is wrong for so many reasons. It is hard to know where to start with this. The major fallacy with the whole thing is that these machines are just somehow discovery devices (in the most naive sense) of some sort. You build it, switch it on, see what’s there, write the paper and the press release (not necessarily in that order) and then you’re done. Completely neglected is the notion of such an experiment as a device for […] Click to continue reading this post
