I hope you’re having a really great and peaceful holiday time, whatever tradition you use to celebrate the season. I’ve been rather taken up with a number of things, including a bit of family travel, and family visits, which meant that I lost some blogging days. Sorry about the quiet.
Is anyone else hoping that (when they release it in the future on DVD/Blueray) the director’s cut of Peter Jackson’s “The Hobbit” will actually be 40 minutes shorter than what’s out in cinemas now?
-cvj
…of Mexico. It was an excellent evening again this year (November 30th, actually). This was the second one (the first was in 2010) and I think the idea is to try to make it an annual event. It is in that great space downtown, Vibiana, the former Cathedral of St. Vibiana (now de-frocked, I suppose).
Anyway, the fellow (photograph right) making something (whatever it was) using liquid nitrogen caught my scientist’s eye (I usually carry a couple with me when I go out). It reminded me of the ice-cream people used to make at various departmental parties in physics departments in my past. (Always seemed like a good idea for novelty, but I never ate any of the ice-cream. I think I’m a fan of making things like that the slow way, letting the flavours settle in…) I wondered what he was making, but did not wait to find out since I was not on my own and a crowd immediately formed around him.
What happened a short time later was a bit unexpected. I enjoyed listening Click to continue reading this post
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 I 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:
[tex]
\nabla\times\mathbf{E}=-\frac{\partial\mathbf{B}}{\partial t}\ , \qquad \nabla\cdot\mathbf{B}=0\ , \\
\nabla\cdot \mathbf{D}=\rho\ , \qquad \nabla\times\mathbf{H}=\mathbf{J}+\frac{\partial \mathbf{D}}{\partial t}\ ,
[/tex]
where [tex]\mathbf{D}[/tex] and [tex]\mathbf{H}[/tex] are related to [tex]\mathbf{E}[/tex] and [tex]\mathbf{B}[/tex] using the “constitutive equations”: Click to continue reading this post
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
You might remember that during the Spring and early Summer I was deeply embroiled in making a film. (See several earlier posts, e.g. here, here, here, and here).) It was a short film to celebrate the 50 year anniversary of the Aspen Center for Physics, and I was keen (in my role as filmmaker) to give it a treatment that benefits from my being a theoretical physicist, and one who is familiar enough with the Center, all in order to get the right tone of the film. (Jump to the end of the post if you want to see it without more background thoughts.) There’s a spirit of the Center that is quiet, reflective, and inspiring of thoughts that need time to be explored, so I definitely did not want the usual loud, buzzing, overly busy type of film that you often see about science activity. It did not seem appropriate. Working with Dave Gaw (who was an awesome principal cinematographer and editor for the project) and with Bob Melisso (who shared some of the production and direction work with me), I think the result strikes the right note overall. A fun side note: I got to design a number of unique (and definitely handcrafted) elements for the look that I think you’ll like and recognize from other visual work of mine you’ve seen on this blog, and just as with my earlier film projects from 2009 (see here and here) it was a real buzz to help figure out how to make them fly, and then see the elements come together in their final form up on screen.
People really seemed to like the film a lot, from what I’ve heard. (It was shown extensively at many of the Summer events celebrating the 50th at the Center.) So while it did take a lot of my time, it seems like it was time well worth spending since Click to continue reading this post
The 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
Sort of stuck this morning. I was up at 6:30am (more or less my usual time these days) with good intentions to get back to do a nice stretch of work on The Project for the first time in a while. But it is almost 10:30am and I’ve done nothing (not counting procrastinating, making fruit compote for pancake breakfast, sending a bunch of emails, and so forth).
It is difficult sometimes to reboot back onto task on a project when one is suddenly done with one of the major things pulling you away from it. Classes are over, you see, and so I am transitioning into a different mode, and not super-efficiently.
I think maybe before I have to leave to run errands out in the world (after lunch), I must get something done toward Click to continue reading this post
“I know! Clamp a clamp to it, and then clamp to the clamp with two other clamps…!”
Turned out to be a rather nifty solution.
Urgent jobs needed doing at home. More or less done…
-cvj
Penultimate lecture today in the graduate electromagnetism class. These last four lectures are a lightning tour through some important concepts – showing how many of the things we’ve been doing all semester fit with Special Relativity. (For example, amusingly, showing that the Lorenz gauge condition is in fact Lorentz invariant…) It is fun to show a powerful example of how an important guiding principle (such as writing equations in a Lorentz-covariant way) can end up making several features of the theory seem much more natural, while also leading to new physics. This is fun to do, although it does mean that I end up writing whole new notes for this since I am not a fan of the way some of these electromagnetism books (Jackson included) decide to treat time in an odd way, such as treating it as imaginary (which must be so confusing to some students) just so as to write Lorentz transformations like a rotation, or using mostly negative signatures for spacetime, and so forth. And, inexplicably, using different units of measurement from the choices made in the rest of the book… Anyway, so the last two lecture-writing sessions have mostly been one of fiddling with minus signs and factors of c, 4 Pi, minus one, and so forth. Joy. Well, the group seems excited since they’re beginning to see things that they’d seen in other classes and it is all making some sort of sense now (Klein-Gordon equation, duality, etc., etc…) I think the last class will show how many of these things flow from variational principles. Maybe I’ll find a little time to do the Born-Infeld model? I’m excited too, although I’ll be sad to end the class and stop working with this fun group of students.
Today I managed to grab a few sketches on the train. This afternoon coming home on the Expo line these two snoozing gentlemen were kind enough to sit still for a few minutes each for me to get down a few impressions of their features. This was all helped a bit by the train sitting still for a while as we waited for a truck to get off the line. Apparently it was parked or stuck there.
Perhaps not helpful was this young guy who watched me drawing and then decided Click to continue reading this post
Recall the mock science doc I pointed you to earlier, the Fifth Feeling? Well, all the episodes are now online in HD, on Funny Or Die. You can see the remaining episodes (3, 4, and 5 since I posted) now, or watch them all, since they look great in HD. (Or maybe because you’re simply a huge Ray Wise fan from the good ol’ Twin Peaks days..?) Here’s episode 1 again to get you started if you’ve not seen the setup, and from there you can jump to the others*:
Ok, ok. I can’t resist posting episode 4 as well, because that doorstep conversation cracks me up every time…
Click to continue reading this post
…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:
It’s Thanksgiving! If you’re in the USA, I hope you’re having a good one so far. It is time for Asymptotia to take a trip to the kitchen, this time to make a dessert contribution to a meal at some friends’ Thanksgiving dinner party. I was going to make an apple pie, like I did some years back for a Thanksgiving, but apparently one of the other guests is bringing one. So I went with another simple and reliable preparation, an upside down cake with something seasonal on it. I went to the farmer’s market at Barnsdall Park yesterday (I missed my usual, the Hollywood one, since it is on Sunday and I was in New York that day) and saw that they had pluquats (crosses between plums and apricots), and they were the prime candidates for the cakes (plural since I decided to do two). I made them earlier today.
It started with chopping up the fruit into thick slices and making the topping. This is made from a stick of butter (half a cup – I am using US measurements), melted in a skillet and then cooked for a few minutes on a low flame with 3/4 cup of sugar and some spices (nutmeg and cinnamon, ground – my addition). I put that at the bottom of the ten inch pan I had ready. (I did two copies of everything, by the way) Then I Click to continue reading this post
Here’s the first slide of my TEDYouth talk from Saturday. It was time consuming but fun to draw all those hands and tiny items of various sorts. The whole talk was about what I call “hidden structures”, which in a sense is what my field (high energy physics, particle physics, cosmology, string theory, etc.,) is all about. To help motivate it all, I started by talking about opening up your smart phone and figuring out how it works by taking it apart and discovering the components inside, and using the rules of how to put them together to deduce the structure of other things (see that second stage of the slide being delivered on stage*).
Since I’m hugely into getting people to learn by really getting stuck into things Click to continue reading this post
After arriving back home from New York on Sunday night (late) my next tasks were to sleep and wake up super-early to write some lecture notes on various approaches to treating diffraction (vectorized Kirchhoff integrals and so forth) for my class, and to grade several weeks of homework assignments…. all before the day’s guest (Howie Haber from UC Santa Cruz) arrived to visit and give us a departmental colloquium entitled “The Higgs Boson Unleashed”. It was great, and included discussion of new results from the LHC announced just last week. Then there was dinner in one of the excellent new downtown restaurants where I seem to have become a regular (nice to be remembered by the wait staff sometimes).
Today I must think about what I’m going to say in a colloquium I must give at Cal State Long Beach on Monday… But before then I think I need to have a slow day as I’ve really not stopped being in extreme headlong motion on various projects and deadlines for over three weeks now.
Of course, I do try to create moments of quiet whenever I can. It is important to me. Sketching practice helps. I’d taken my watercolour pencils and little portable fillable Click to continue reading this post
That was a fantastic day! Worth all the preparation. I am too exhausted to tell you much about it in person, but why not look at some of the descriptions of the talks and other activities that were put up on the TEDYouth blog? You can see a report from session 1 here and from session 2 here. In my photo you can see the two main hosts Kelly Stoetzel (who also co-curated the event, as she does for other TED events) and Rives getting everyone ready for the whole day that lay ahead. I was super-impressed with the standard of all the talks, and the variety. And I got to talk to a lot of the speakers at a reception afterward, which was great! The young people seemed really excited to be at the event and meet the speakers, and I enjoyed talking to them too – so many great questions!
Congratulations to all of the TED people for putting on such a great event.
-cvj
