Category Archives: work

News From the Front, IV

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So imagine the following:

You’re walking along the street, minding your own business, and somebody walks up to you and tries to sell you a string theory. So you stop and examine the goods, since you’re in the market for string theories, on the lookout for any that might be novel, useful, bright, or shiny, etc. You never know when one or other property might come in useful.

Question: How do you know that it is a string theory? Let me be sure to point out that it comes with a lot of the defining path integral done for you. In other words, you don’t have to do the integral over string world sheet metrics and world sheet fields. This was done in the factory for you. What you have access to are parameters such as the coefficients of the operators in the theory, and you can also adjust the value of the string coupling.

So a lot of the stuff you would recognize as a string theory in your typical string theorist’s notebook have been cleaned up. They’ve been integrated over. The observable physics actually never cared about them (the technical details of summing over metrics – slicing up the moduli space of inequivalent metrics properly at each genus, etc etc…. all done), assuming you’ve done the integrals properly. The factory did it all for you.

So what criteria do you use to decide that it is a string theory at all? Actually, this is not an idle question. Think about the issue in the context of trying to understand some […] Click to continue reading this post →

Field Trip, I

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As part of the Freshman Seminar I told you about earlier (e.g., here, here and here), we went on a field trip to MOCA in nearby downtown LA.

We went to see the exhibition of drawings by Eva Hesse. Hesse is very well known for her sculpture, and among the things she did, I think that a rather splendid one in this context is the one below. It is an example of those that resemble three dimensional renderings of her interesting use of line on the paper.

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This one (not in the exhibition) is called “Metronomic Irregularity” (I think it has a number as well… there are several pieces of this title done by her).

The group is standing in front of the sculpture I posted about earlier. There’s Ashley and Adam, left and middle. Jeff (on the right in the picture) -who is not a freshman, but a senior who does physics research projects with me- came along as well. We had a rather good time, taking […] Click to continue reading this post →

New Colleagues

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Ah! The joy of new colleagues! I have somehow forgotten to tell you one piece of the great news that we had here at USC Physics and Astronomy recently. We got three new faculty, and one of them is here in action (I’ll tell you about the others later), telling us about the physics behind the 2006 Physics Nobel Prize. This is Cosmologist/Astrophysicist Elena Pierpaoli:

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She’s one of those people who works closely on (among other things) the data from […] Click to continue reading this post →

Lighting Up Your Quantum Class

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I forgot to tell you about this last week, so here goes. The colloquium last week was given by John O’Brien. One of the perks of the job of having to organize the department’s colloquium series is that you can use it (on rare occassions) as a blunt tool to find things out. I’ve always been curious about connecting the name I saw on one of the labs downstairs to a face. John’s lab, primarily part of the Engineering department, uses a little of the space in our building, you see, but I’ve never really made the connection between the face and the name. It certainly seemed that the USC Center for Photonics, of which he is part, was certainly up to some interesting and fun stuff, and so, egged on by another curious colleague, I sent him an invitation to give us a colloquium. He generously accepted, and here he is:

The talk -see the abstract here- was excellent. As you can see from the website listing the faculty in the centre, they are concerned with all sorts of fun things to do with very small scale devices which do rather clever things with light, such as nanoscale semiconductor lasers. The reason that the talk was excellent, in my opinion, was because it was not a standard device+engineering talk that you can often get from very good engineers who nevertheless don’t neccessarily appreciate what aspects the physicists care about. Those talks can often be pretty pictures and […] Click to continue reading this post →

Visions and Voices

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This year, there’s going to be even more to do on the USC campus to broaden your mind, and several events which link USC with off campus venues such as theatres, museums, and performing arts centers. The (then) new Provost, Max Nikias, announced his “Arts and Humanities Initiative” in his … Click to continue reading this post →