Category Archives: string theory

A Very Long Straight Line

By | | , , , ,
13 Comments

I’ve been multitasking in an interesting way. Sort of. I’ve reached a certain point with some computations I am doing that I cannot go beyond by analytic means. LinePlotThis means that I can’t extract the physics I need by doing algebra and other exact manipulations on paper any more. Progress can continue however by using numerical means, employing a computer to solve the highly non-linear equations and extract the juice. There are several steps involved, and ultimately, I want to determine how a certain physical quantity depends on another physical quantity. (I’m sparing you the trouble of knowing what the details of the physical quantities are, since it does not matter for the thing I am trying to tell you. It relates to quantum field theory, gravity, and string theory, which connects the two.)

I can see that dependence quite clearly if I simply plot a graph of one versus the other, and in this case I need the computer to work out what the points on that graph are. I actually don’t know the answer for the cases I really am interested in, nobody does (that’s why it is research!), and so that’s what I want to find. I want lots of points to get a nice smooth graph, so the computer has to compute a lot of points, and I need to run it for a long time since I want it to compute the points very accurately. So I wrote a program (in Maple) to work on the problem, studying just one […] Click to continue reading this post →

TED Youth Talk – Hidden Structures of the Universe

By | | , , , , , , , , , , , , , ,
3 Comments

cvj_TED_YouthYou might recall that last year I gave a talk at TED Youth, in their second year of short TED talks aimed at younger audiences. You’ll recall (see e.g. here and here) I made a special set of slides for it, composed from hundreds of my drawings to make it all in graphic novel style, and somehow trying to do (in 7 minutes!!) what the TED people wanted.

They wanted an explanation of string theory, but when I learned that telescopesI was the only person in the event talking about physics, I kind of insisted that (in a year when we’d discovered the Higgs boson especially!) I talk more broadly about the broader quest to understand what the world is made of, leaving a brief mention of string magnifytheory at the end as one of the possible next steps being worked on. Well, they’ve now edited it all together and made it into one of the lessons on the TED Ed site, and so you can look at it. Show it to friends, young and old, and remember that it is ok if you don’t get everything that is said… it is meant to invite you to find out more on your own. Also, as you see fit, use the pause button, scroll back, etc… to get the most out of the narrative.

I’m reasonably pleased with the outcome, except for one thing. WHY am I rocking […] Click to continue reading this post →

Congratulations!

By | | , , , ,
7 Comments

In other interesting announcements today, the great physicist Alexander Polyakov has been given the Fundamental Physics Prize. (See the announcement here.) There was a remarkable award ceremony in Geneva yesterday, hosted by Morgan Freeman, and with lots of Physicists and others celebrating great work in various areas of physics. Polyakov has been a key and brilliant leader in many areas of theoretical physics, and influenced so many ideas and techniques that have fed into the whole field, and so this is a well deserved recognition.

I must note that it is a bit sad (to say the least) to do a google search on the news about this prize and see so many articles with a lot of just plain stupid focussing on a big prize going to a “string theorist”, as though this is somehow negative or ironic, and also missing the fact that Polyakov’s contributions are so broad and far-reaching […] Click to continue reading this post →

Interview!

By | | , , , , ,
7 Comments

A while ago I got an email out of the blue from an enthusiastic young fellow who wanted to do an interview with me on camera for his YouTube channel. After we bounced emails back and forth a bit and I got a sense that this was both legitimate, worth supporting, and that I had time to do it, we agreed that we’d meet to do it. So we met at the excellent Mystery and Imagination bookshop in Glendale, and he set the camera running and threw a bunch of questions at me. We talked about all sorts of things from dark matter, the LHC, supersymmetry and string theory to trumpets, jazz clubs, and noir films.

It was fun, and you can find the results on his YouTube channel (here), that he hopes to populate with more interviews with people working in science and other topics. He’s got an interview with mathematical physicist John Baez up there already, so go and look.

Below, I’ve embedded the interviews with me, for your convenience.

Enjoy! […] Click to continue reading this post →

They Seemed to Like It

By | | , , ,
1 Comment

What? The final exam I set on Friday. I spent a lot of time trying to get this final exam right. The problem is that I tend to decide at some point that I want to set an “interesting” exam, and then this usually ends up being more work for me than for the students, since you not only have to think of the questions and make them the right level of difficulty (made harder by being open book and, in this case, a take home -well, take to where ever for 4 hours), but then endlessly debug to see that it has no mistakes (since I won’t be present to answer questions). This time, I spent a lot of time on units, since I wanted to set an exam that kept all the factors of c and mu and epsilon present in all the relativistic notation and right down to the final unpacked Maxwell equations and all the quantities they computed in various examples. I decided to have them explore a little non-linear electrodynamics, since everything they’d seen was mostly linear. You start with the familiar (Maxwell) form of the equations:

[…] Click to continue reading this post →

Local Connections

By | | , , , ,
5 Comments

Well, Thursday’s meeting was a blast! I had decided not to try to get people to RSVP for the meeting this time, and so when it came down to the day before, I had no idea how many were going to show up. This meant that I had to make some guesses about how much coffee and tea and cookies to organize, which was a little bit of a challenge. But just before 9:00am people began to show up, and kept showing up, and by time I was ready to start off the day’s meeting, there was a really good crowd!

In the end it was a great day, with five really good talks and lots of excellent discussion. […] Click to continue reading this post →

Southern California Strings Seminar

By | | , , , ,
3 Comments

Southern California String Seminar May 2011 in progressThe next Southern California Strings Seminar is on Thursday 13th December! I’ve now made the website for this one and it is here. Come back to it from time to time to see the updates of talk titles as speakers let me know what they are. It is a one-day event filled with five talks and plenty of time for discussion. I’ve snagged a lovely room in the Doheny library again. (Photo left has a shot of the room we used last time it was at USC in May 2011. The most recent one was over at UCLA.)

You are welcome to come and do physics with us! Also, if you’re part of a group in […] Click to continue reading this post →

Talking

By | | , , , ,
Comments Off on Talking

…Again. I’ll be on the road again this morning. Heading to California State University Long Beach. They invited me to give a colloquium a while back and I agreed, and when I returned from New York last week I realized I needed to urgently spend a chunk of time thinking about what I was going to talk about, and designing a set of slides for it. The last couple of days saw me devoting a lot of time to it. Eventually I decided to dig back into ancient times (the 1990s) surveying some of the interesting things we’ve learned about strong coupling phenomena (involving unexpected reorganization of degrees of freedom and the number of spacetime dimensions at times), and then discuss what it all might be good for in view of work going on in the last decade or so.

Come to think of it just this moment, this is a chance to do a tribute to David Olive, who passed away earlier this month. (He was one of my professors when I was at Imperial College in the ’80s.) Ideas of strong/weak coupling dualities and their utility were given a huge boost by his work in this area from decades ago, perhaps the most famous being Montonen-Olive duality… I must remember to mention that in the talk. (See here for an archive of 2004 talks in celebration of his work. I borrowed the image to the right from there. I do not know who took it.)

Here’s the title and abstract: […] Click to continue reading this post →

TEDYouth Approaching!

By | | , , , , ,
4 Comments

Ack! As you know, it has been an incredibly busy semester for me, but I still try to find time to tell you a bit of what is going on. Not long ago I got an email from the TED people asking me if I’d like to talk at one of their events. This event is for young people, called TEDYouth. It’ll be on November 17th. Well, this is such a good cause – how can I not do this?

TEDYouth speakers photoYou can see the announcement of the “incredible lineup” of speakers on TED’s site here. (I linked the photomontage they used there.) I’m looking forward to being in the audience to hear some of these guys talk!

So of course, I now find myself a week behind where I should be in terms of preparation, and in the middle of a whole bunch of other deadines… […] Click to continue reading this post →

Strings 2012 Talks

By | | , , ,
2 Comments

I did not make it to the annual “Strings xxxx” conference this year (where xxxx = current year), but I heard that it was good. It was held in Munich. See the lovely poster on the right. (I wonder who did the splendid painting?)

The organizers did a great job of rapidly updating the website with slides and video of the talks so that a wider audience can benefit from them. The video page is […] Click to continue reading this post →

Working Group

By | | , , , , ,
2 Comments

It wasn’t all lecture halls, discussion rooms, and cafeterias for the workshop. The organizers arranged for a boat tour last week, and we all sat on one of those splendid long, wide and low tour boats that you often see on the canals in Amsterdam. It was nicely equipped with a bottle of wine at each table, and the crew members handed us each a glass of sparkling wine as we embarked. Very nice. There was a lot of fun chatter from each table for the whole trip around the canals (so much so that they stopped the attempts to inform us over the PA system about some of the sights we were seeing, since the sound was drowned out by the conversations), covering (from what I could hear) a wide range of topics from well beyond physics to matters concerning topics presented in the workshop.

Sometimes pads of paper and pens appeared. Above is a group (David Tong, […] Click to continue reading this post →

The Bridge

By | | , , , , , , ,
1 Comment

The workshop has been fantastic, overall. In between discussions, the talks, and some thinking about my own projects, I’ve had some time to wander a bit, and look around. Yesterday after lunch I wandered a bit and then found myself settling down and doing a sketch of a bridge at a junction with lots to see. The Amstel is joined by Prinsengracht canal here, and it was fun to sit a while and put down some pencil lines, followed by firmer ink lines. I pulled the result into the iPad and splashed on some colour for good measure.

Having finished the paper last week, it has been fun to field questions about it from various people, as well as think at a more leisurely pace about the next […] Click to continue reading this post →

Slow Writing

By | | , , , ,
6 Comments

Well, the workshop is going well. I had to miss a talk this morning in order to carry on with this writing of a paper I was doing. Basically, we’re over due in producing our submission to a special volume of some publication or other that is going to be all about magnetic fields and models of strongly coupled matter… As you may have gathered by now, I’ve dabbled in magnetic fields for some several years by now, so it was natural to be asked. My collaborator in a lot of these dabblings, Tameem Albash, and a student, Scott MacDonald, and I have been working on a suitable project for a while, and due to my travels and entanglements with a previous project, I’ve made us all a bit late.

The last few days have been difficult for writing. I’d forgotten […] Click to continue reading this post →

Documenting

By | | , , , , ,
5 Comments

Speaking of film projects involving science, I’m involved in two new ones I’ve been meaning to tell you about. I’m working on producing a short film about the Aspen Center for Physics, to be used in the upcoming 50th Anniversary celebrations. My partner in crime on this is Bob Melisso, who I’ve worked with before a number of times, and it’s already been interesting, and fun. I think that the final piece ought to be interesting at the very least. I’ve been trying to work in a very particular look and feel for the film that reflects something about the nature of the work that goes on at the center (both its content and how it is done), and so there’ll be lots of chalk, scribbling on boards, reflections on the creative process and how a place like the Aspen Center helps, and so on and so forth.

We’ll be shooting from time to time over the early and middle Spring, and doing the […] Click to continue reading this post →

Entangled

By | | , , ,
4 Comments

Gosh, I got a bit swamped there over the last week. Several things took me away from sitting down and doing a blog post, including teaching my class (more on that shortly), working on a film project (more on that longly) and doing my taxes (late this year – bah!) and the usual raft of committee meetings and so forth. But one of them was locking myself away for two days with my computer and a web connection and writing a paper from start to finish with Tameem Albash. We’d more or less completed the bulk of the project over two months ago, with some very interesting results that we’d talk about from time to time to try to understand what was going on, but I held things up, being distracted by several other things (some of which you know about from this blog). We decided two weeks ago that we’d just finish the thing once and for all, and then somehow ten days went by with me not getting to it. Then I decided to close the door and just do it. So from lunchtime on Friday through lunchtime on Sunday I became a recluse (kind of) and I wrote, in turn with Tameem, as we emailed and IMed back and forth, until we had a nice paper entitled “Holographic Studies of Entanglement Entropy in Superconductors”.

It is a project I’ve been hoping to do for a long time, but not all the pieces were on the market until late last year. The entanglement entropy has been a quantity of interest among physicists in various fields for years, especially in the condensed matter and quantum information community, and is regarded […] Click to continue reading this post →