I had an early rise this morning, to make it down to campus early enough to set up (with the help of my co-conspirator Tameem) the room for the all day meeting I mentioned earlier, in order to start at 9:00am. All worked well… And things are progressing nicely (see photo of some of us in the lovely room we’re using) with local participants from USC, UCLA, UCSB, and even Stanford! It is excellent to see such support and enthusiasm for this semi-annual event!
-cvj
We’re hosting the next Southern California Strings Seminar here at USC. It will be on Friday 6th May. I’ve been working on it a lot over the last several days* and put the finishing touches on the arrangements just this morning.
There’ll be no Saturday morning component this time, since there’s yet another huge event down at USC this weekend, and things will be rather disrupted, I understand, as there’ll be lots of people, street closures, and so forth**. (It is the Revlon Run/Walk event in exposition park, across the street from us, an excellent event!)
So I’ve packed five exciting talks into Friday, and I think it is going to be fun! Here’s the schedule:
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My colleague Chris Gould, who organizes the California State Science Fair (currently on down at the California Science Center!) is also working on the Intel International Science and Engineering Fair (ISEF) this year, to be held at the Los Angeles Convention Center. In addition to more volunteers to help out in a range of capacities, they need more judges for the fair in many categories, so please consider giving of your time to help out.
These things can be fun, as you may recall from my posts in previous years on similar fairs (e.g. here). There’s apparently a specific need for more people in aspects of life sciences and environmental sciences, so please pass this message on to people who you think might be suitable and interested.
Here’s an extract from Chris’ recent email about this: […] Click to continue reading this post
It has been another rather busy week this week (including a marathon seven-hour video interview!) and so posting was a bit light. I apologize for this, including for not getting to blogging about an event (or cluster of events) that I’ve been gleefully waiting for since the news broke last Fall that (as I’d mentioned back then) the LA Times Festival of Books is now being hosted by USC. This is something I fantasized about many years ago, in fact – I simply think it is a better fit for the city of Los Angeles for many reasons.
Anyway, the first festival of the new era is tomorrow and Sunday, with a wonderful program that can be looked at on the LA Times website. It will continue to be the largest literary festival in the USA (and perhaps beyond?), and it is hoped that it will get even larger… Next year, we’ll have the new branch of the subway system running, giving three stops at the campus (hurrah!), but in the meantime there’s a dedicated shuttle bus connecting USC to Union Station downtown and the Convention Center (not to mention all the many regular public transport links), and so you don’t have to bring your car to the area to deal with parking issues.
As you know from my blogging about all this in previous years (see list of links at the end), in a sense the whole thing kicks off the Friday night before (tonight!) with the […] Click to continue reading this post
Some of this weekend was spent in the mountains a few hours East of the city, where we had a departmental retreat for a short while. It was fun – lots of fun. There’s a lot to be said for going off to some other place with your work colleagues, being together with them for meals, business, and recreation, and getting to know people you had not met before, or getting to know better people you’d already known.
There were several short talks from people sharing a bit about what they or their research group have been up to, with coffee breaks and meal breaks. The latter were signaled by a nice gong, and we were served tasty vegetarian food that everyone seemed to enjoy (even those who eyed longingly the In ‘N Out Burger in the town at the bottom of the mountain before making the trip up – you know who you are!) with wide ranging conversation among ourselves and occasionally with the Buddhist monks and volunteers who run the centre. (Hence the sitting cross-legged on mats in the above picture…)
The evening had a few more talks and then was free for socializing. A large game of trivial pursuits broke out and hilarity ensued in one corner, along with chatting, guitar strumming and drawing (me) in other corners.
After what was a cold and windy night outside (I was glad of the extra layers I brought), Sunday had an early start for breakfast, 7:30am, and then a large group headed off for a hike. I decided that I needed to get some work done on The Project and stayed by the toasty fire in the dining room and did some drawing and inking, listening to […] Click to continue reading this post
I’m lounging around. In Cincinnatti Ohio. Why? Well, it has been a long day, and I’m tired. I spent the whole day yesterday traveling to get here, changing planed in Chicago, eventually getting to my hotel at 10:00 pm, having arisen at 6:00am. I spent the flying time thinking about physics and writing the talk I was invited to give here as part of the regional SPOCK meeting at the University of Cincinnatti. The letters stand for something, but I can’t recall what it is right now. It does not mean, as the title might suggest, that several emotionally-challenged and otherwise tv-cliche-handicapped individuals were meeting to discuss arcane matters in a room somewhere. It was a meeting of several people from the region’s string theory community to discuss…. Ok, ok, Ok…stop giggling!
I got up at 7:00am -really 4:00am my time- transferred all my pages of notes to the iPad, and got ready, leaving to do the short (I assumed) walk to the physics department in the wind and rain. I enjoyed that bit… I had however mis-estimated how long it would take me to get to the Physics department building, largely due to […] Click to continue reading this post
Ok, so how long did it take you to spot that NPR’s 3D story today (“Advances In 3-D May Mean No Ridiculous Glasses”) was an April Fool joke? I thought it was rather excellent, and was in unbelieving mode from the moment that they began to talk about the surgery, which is utterly ridiculous, and made no physics sense to me at all. But the funniest give away was the line:
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The exo-planet hunting craft Kepler has found 1235 candidate planets orbiting other suns so far. The APOD site has a lovely composition by Jason Rowe showing representations of all of those suns with the spots on them that represent the planet transiting in front of them (that’s how they are found by Kepler). They are all nicely […] Click to continue reading this post
Tomorrow’s full moon is going to be the closest to us in 18 years, apparently. It’s called a supermoon by some, and no doubt some will try to link it to many major events here on earth, both natural and man-made (if you’ll forgive the distinction). I won’t do a long post about this issue, but instead refer you to Phil, who is excellent on the science of this and related subjects.
What I will say instead is that all commentators seem to have missed that this is the best opportunity in years to gather moon-milk! Get out your ladders and buckets and go for it!
What am I talking about? At my last birthday I was given* a lovely collection of stories by Italo Calvino, and the first one is entitled “The Distance of the Moon”. It begins with a description of the fact that a long time ago the moon orbited much closer to the earth, as you may know, and then weaves a delightful story from there. The story involves reminiscences, by the narrator Qfwfq, about those good old days when the moon came so close that once a month (yes, I know) the earth’s inhabitants would take boats out onto the sea to the where the moon came close and climb up a ladder to its surface to gather the much-desired substance known as moon-milk. A lovely extract follows: […] Click to continue reading this post
It was a fun week in the string theory class this week, as we got to some major landmarks that are always fun to teach. We’ve uncovered the extended objects called D-branes (see numerous previous posts for how useful and important these objects are in string theory research) in all their glory in the lectures before, and deduced lots of their properties, such as the form of the action that determines how a D-brane moving in spacetime responds to the various fields (including the geometry) created by the string theory. That’s all fun, but then the key thing to do next is to compute the mass of these dynamical objects, or the mass per unit volume – the tension. Computing it fully, with no hand-wavy factors. Your mass measures how strongly you interact with gravity. So you can measure it by studying the gravitational interaction between masses. (You do that when you step on a scale to measure your weight… well the scale does it by showing how much force it takes to stop you from falling through the floor toward the center of the earth…)
So in class this is when we go all Polchinski and unpack the tension computation, stopping to admire the various features of string theory you learn along the way, and seeing how simply beautifully the various basic features of the superstring theories that we’ve met in the last few lectures encode themselves in one nice object – the vacuum amplitude [tex] {\cal A }[/tex] from the cylinder diagram representing either exchange of closed strings (including quanta like the graviton – this is what you focus on to learn what the mass is) between a pair of D-branes, or an open string with its ends tethered to a pair of D-branes going in a closed loop. That there are two ways of looking at the diagram, an open string way (running time around the cylinder) and a closed string way (running time along the cylinder) is a hugely powerful thing, and is at the heart of so very much of what we do in string theory these days especially – including a lot of what I’ve told you in previous posts (see e.g. here and here) about applications to things of interest in current experiments.
One of the fun things about all this is that the answer is actually [tex]{\cal A}=0[/tex]. It is zero because all the infinite modes of oscillation of the string gather themselves up nicely to give a factor:
[tex]
q^{-\frac{1}{6}}\prod_{n=1}^{\infty}(1+q^{n-\frac{1}{2}})^8-q^{-\frac{1}{6}}\prod_{n=1}^{\infty}(1-q^{n-\frac{1}{2}})^8-16q^{\frac{1}{3}}\prod_{n=1}^{\infty}(1+q^{n})^8=0\ .
[/tex]
Think of [tex]q[/tex] as a book-keeping device that lets one track energy contributions (in the power of it that appears in a term if one expanded this expression), and how many […] Click to continue reading this post
Before jumping on to a plane last week, I went to meet some filmmakers to do a quick shoot we’d arranged. They are making a series of shorts for TV and myself and one of my co-contributors/presenters from The Universe, Laura Danly (from the Griffith Observatory) are doing some on-camera bits for them. (There may be others involved too, I don’t know.)
I mention this since there are two bits of novelty, I think. The first is that it is interesting that the company that commissioned these pieces are looking for shorts (4 minutes or so, apparently), and will be interspersing them with their programming in some way that will be somewhat unusual for current TV formats in the USA. I always welcome opportunities to help put some fun bits of science out there for the public, and in short bites mixed up with other things is just great!
The second novelty is that they are in 3D. You’ll recall, perhaps, that last year I contributed to a special show that was commissioned in 3D as part of the drive […] Click to continue reading this post
Ok, so it is last week’s Sunday bread, but you get the idea. This week’s is actually in the oven this very minute. I feel that all is more or less ticking away alright in my life’s day to day scheduling if I am getting bread made each week. I … Click to continue reading this post
Struggling for a post title, I went for a slight critique of the work I did on the character you’ve seen earlier*. She’s been grabbed from a panel showing her looking for a seat in a cafe where a conversation (about a physics issue) is to continue.
It is a large panel showing the layout of the cafe with all the people sitting and reading and talking and so forth, and she’s one of several small figures in it, so it is probably not that big a deal that she has somewhat heroic proportions here as compared to her more ordinary proportions in other panels.
Heroic here refers to the various choices of proportions you can give to figures, usually based on how many heads tall they are. You might have heard of people talking about how many heads tall a figure should be.
Well, there really is no “should be”, and different practitioners use different […] Click to continue reading this post
I’m guessing that a lot of you (especially those doing graduate work in Biology Labs) will just love this video, because you can relate to it. It’s about that frustrating feeling that (for one reason or another, or several) you’re stuck doing the endless project from hell… We’ve all been there. Oh, and it is done in the style of a Lady Gaga video I am told (not having ever seen or heard a Lady Gaga video, as far as I am aware, I can’t attest to this). Video after the fold:
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So you’ve probably heard the news, but just in case I thought I’d mention it here. The Kepler observatory, up there in orbit keeping an eye on things for us, has found a bumper crop of planets orbiting a sun-like star a mere 2000 or so light years away. It is amazing what you can see if you look closely. Every now and again the star’s brightness dips ever so slightly, and that tells you something has passed in front of it – another planet. Or in this case, once you’ve analyzed the pattern of dips, as the team of astronomers did, six planets!
These are not earths, although the headlines all over the news sure try to grab you in […] Click to continue reading this post
