Category Archives: work

All Space Considered

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You may recall that last month I hosted the First Fridays portion of the Natural History Museum’s day of celebration, where I introduced and steered the questions for JPL’s Adam Steltzner (lead engineer of the the “7 Minutes of Terror” Mars Curiosity landing). A fun event indeed. Well, this month I’ll be at another First Friday event, but for the other wonderful classic science space in the city, the Griffith Observatory.

They have a First Fridays series too – not to clash intentionally, I’ve recently learned upon inquiring – and it is a goal of mine to connect the relevant parties and find ways of having these events and spaces intersect with each other fruitfully, maybe. Perhaps participating in both of them is a good way to start. The “All Space Considered” event is a series where there’s a panel of scientists […] Click to continue reading this post →

Effective

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I just learned* that Ken Wilson died a few days ago (Just 15th). Wilson is another of the giants that you don’t hear much about in the popular media coverage of the great ideas in Physics that form the bedrock of so much of what we do. You still get people saying utter nonsense about “hiding infinities” in physics and so forth (often in discussions on blogs and various similar forums (fora?)) because what he taught us all about effective field theory and the renormalization group still is only taught in some advanced classes on quantum field theory (and still not as well or frequently as it should be in such classes … it has only relatively recently begun to be put at the forefront in textbooks on the subject, such as Tony Zee’s). In the cut and thrust of the mainstream of research though, I’m happy to see that so much of Wilson’s legacy is in the most basic fabric of the language we use to discuss results and ideas in particle physics, condensed matter physics, quantum gravity, string theory, and so forth.

I had the distinct privilege of having Joe Polchinski as a mentor for some of my postdoc years, who is known as being one of the current giants on the scene who […] Click to continue reading this post →

100th Birthday Fun!

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[caption id="attachment_14281" align="aligncenter" width="499"]The crowd watching Devo on stage at the Natural History Museum's 100th Birthday celebration (click for larger view) The crowd watching Devo on stage at the Natural History Museum’s 100th Birthday celebration (click for larger view)[/caption]The 100th Birthday party at the Natural History Museum was fantastic! Adam Steltzner’s talk was excellent and it was a pleasure to be the MC and introduce him and run the Q&A. (It was a tall order for me to fill Michael Quick’s shoes, but I gave it a shot.) The audience was really great, and there were several great questions. The wide shot (click for larger view) at the top is a panorama shot of the outdoor concert stage, with Devo just starting their set (GZA of Wu-Tang Clan was on just before). I took it* while standing under the fin whale skeleton that is the centerpiece of the new Otis Booth entryway pavilion that was unveiled just minutes earlier. (See more about that space and other new exhibits here.) Here are a couple of shots (click for larger view) from Adam’s session, where he gave an inspiring talk about the engineering of the landing of the Curiosity Mars rover, with reflections on space exploration in general**:

[caption id="attachment_14261" align="aligncenter" width="300"]Adam Steltzner talking about the Curiosity Mission at the Natural History Museum's 100th Birthday bash Adam Steltzner talking about the Curiosity Mission at the Natural History Museum’s 100th Birthday bash[/caption] […] Click to continue reading this post →

100th Birthday Bash!

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If you’re in town on Sunday 9th June, I strongly recommend coming along to this! The Natural History Museum is having its 100th Birthday celebration with an all day series of events. There’ll be new spaces and exhibits opening, including the new gardens they’ve been building for some time, and so there’s plenty to explore that will be new, and partly outdoors on a (hopefully) lovely day. (See here for an LA Times article on some of the changes.) As the day draws into the evening, there’ll be a real party brewing, with bands, DJs, bars, and so forth (see below). Kicking off the evening part of the proceedings at 6:30pm will be a talk and Q+A with JPL’s Adam Steltzner (of the Mars Curiosity Mission), in a spot hosted by me.

Adam’s a great guy, with lots of interesting things to say and a great sense of […] Click to continue reading this post →

SCSS Report

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scss_may_2013Friday’s Southern California Strings Seminar was a success! Thanks to all who came, who spoke, and the UCLA organizers. I enjoyed all four talks that were put on, and learned a lot from each. (Sera Cremonini is giving her nice talk about duals of hyperscaling violating theories in the photo.)

I was particularly pleased about the talk by Daniel Harlow about the Firewall issue, […] Click to continue reading this post →

Southern California Strings Seminar

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The group at UCLA is hosting the next SCSS, and it is on Friday. More details here. The schedule looks good:

9:30-11:00 Sera Cremonini (Texas A&M): “Probing the IR of hyperscaling violating geometries.”

11:15-12:45 Ken Intriligator (UCSD): “Aspects of 3d N=2 Chern-Simons-Matter Theories.”

12:45-2:15: Lunch

2:15-3:45: Daniel Harlow (Princeton): “On the Computational Complexity of Hawking Radiation”

4:00- 5:30: Eric D’Hoker (UCLA): “Supermoduli and supersymmery breaking”

Enjoy!

-cvj Click to continue reading this post →

Sketchy Look

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magazine_sketch_18th_May_2013On Saturday I decided to have a bit of simple relaxation at home, and sit on the patio with my notepad and some pencils and draw a likeness. I’d not done any practice from images for a while, and frankly my pencil work was very rusty and needed a workout.

So I dug out this month’s issue of a sewing magazine that I subscribe to (what?! well, it’s a long story… let’s move on) that happens to sometimes have interestingly lit and well reproduced photos of faces and sketched for a while.

It was fun (even with the slightly flawed outcome). (Click for a larger view.)

-cvj Click to continue reading this post →

Something’s not quite right, perhaps?

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thing_vs_thing Yeah. Scary, right? I woke up one morning to this result (see earlier posts here, here, and here) from a night of an intensive computer run. It was not meant to be a straight line, but pretty close to it, so I knew that something was wrong with my code. Took me a good long while to trace the problem, but I did in the end. My signal was being swamped by both […] Click to continue reading this post →

Final

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Well, I’ve got to say goodbye to another excellent group of students from my undergraduate electromagnetism class. We had the final today (starting at 8:00am – ack!), and given the lack of rioting, tears, and throwing of rotten fruit during the exam itself, I assume that it was not too bad an exam to sit. Of course, the real measure of what they thought will be how they did in the actual answering of questions, and I’ve not looked to see how that has turned out yet.

Again, I feel a bit sad since it was a good group of students and it was fun to teach them this material. While it is certainly good to move on to other things (I’ve too many projects I want to work on, as usual), I will miss the twice weekly classes with them. Highlights this year include (in no particular order):

(1) The thing I love to do when we are studying dipole radiation – taking the class outside (surprising them somewhat) to look up at the blue sky and connect why it is blue to the computation we just did, including understanding the pattern of the blueness […] Click to continue reading this post →

Lines of Thought

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So I’ve moved on to curved lines now, in case you’re wondering. 🙂 (See previous posts.) The last several days (the research parts) have been taken up with more computations. A lot of the time has been spent calibrating the programs, and trying to assess and understand and characterize the inevitable errors that show up, by running the programs and checking the resulting plots of data points against expectations shaped by hand calculations. Calculating on the train to and from work, I’ve filled several pages of my small notebook with computations, alongside sketches of some of my surroundings as usual (people mostly). As a result (fingers crossed) I think I’ve now understood all the key aspects of the results I’ve been getting, and have good numerical control of things. To get such control, I’ve had to push the error tolerance and the size of the grid of points I’m computing on to regimes where I’m back again to waiting for the better part of an hour for each data point. (One sets up the problem on the computer by making continuous variables, such as space and time, into discrete ones, forming a grid. The problem is then to use various […] Click to continue reading this post →

A Much Shorter Straight Line

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LinePlot2 How is the line coming along? It is very kind of you to ask (if indeed you were). Well, there it is to the left. (See the previous post for background.) In the end, I abandoned Maple since it was taking way too long to do each point, and just for the simple example. (When I tried to do one sample point of the complicated example it took 24 hours and I stopped it before it was done!) The point is that Maple does not easily […] Click to continue reading this post →

A Very Long Straight Line

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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

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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 →