Category Archives: work

Beyond Einstein: Fixing Singularities in Spacetime

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Not long ago David Morrison (UCSB) came to the mathematics department here at USC to give a colloquium.

David Morrison Colloquium at USC

This was a treat for me for many reasons. Here are three:

  1. It’s always good to see Dave. He’s one of the people I’ve known in the field was since my very first postdoc when I was learning to survive in the big bad world on my own after graduate school. I mostly could not understand a word he or anyone there else said in those days (IAS Princeton, right in the belly of the

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Tales From the Industry XVII: Jump Thoughts

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A commenter asked how the aforementioned movie viewing and panel discussion went on Friday (movie: Jumper), and so I thought expand a bit on the answer I gave:
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It went very well. We were at the School of Cinematic Arts, at USC. We had a full house in the Norris Theatre, which was great to see. Most of the audience was students from the SCA, I think, with some of the faculty present, and people from the film’s parent studio, and several others. For the panel, present were two of the film’s producers, the visual effects supervisor, costume supervisor, production designer… basically, the perfect people to have a discussion with about the physics! I won’t try to list all names since I did not catch all of them and don’t want to mis-credit people for being there who weren’t.

Teleportation physics aside for a moment, I’m very impressed with how they realized […] Click to continue reading this post →

Mass Matters

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Well, only four weeks and change behind us in this course, and… the class (see here and here) is ready to understand this wonderful equation:

the schwarzschild solution

and all that it implies. What is it? It encodes the shape of spacetime around a spherical blob of mass of total mass M. No, don’t worry too much about the details, since this is not a lecture about General Relativity….. it is just nice (I hope) every now and again to get a look at the sorts of things we use in our day to day work. This “warped” spacetime encodes what we interpret as the gravitational field (in the old Newtonian language) due to a spherical (or, to a good approximation, almost spherical) mass. Like the sun, or the earth, or that tennis ball in the corner there*. It is an exact solution […] Click to continue reading this post →

Friday Night Wanderings

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It was one of those Friday nights when I was in the mood to get out of the house, but not entirely sure what to get out to. “Out” was more important than “where”, you see. Wanted to do a bit of thinking and to relax and let the heavy week of too many meetings fall away from my shoulders.

In the end, I did a combination of things. After my mood, followed by my at charlie o’s. John Beasley, Nolan Shaheed, Dave Carpenter, Roy McCurdytrajectory, turned away from Pasadena (where I was planning to see Persepolis, as was my original plan – I’ll do it later… really want to see that film) at about 10:30pm I arrived in the Valley and hung out at Charlie O’s which is one of the more happening of the neighbourhoody jazz clubs in LA. (Sadly, in this context, “happening” by LA late night standards means that there’s more than about nine people present.)

There’s always something on each night and you can just walk in and sit at the bar to […] Click to continue reading this post →

Equivalence

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equivalence principle

Well, Tuesday was a big day in class. We reached a landmark – the introduction of one of my very favourite thoughts of the 20th Century: the Equivalence Principle. This is the realization of Einstein’s that there’s something profoundly odd about Newtonian mechanics and Newtonian gravity that hints at something deeper.

Quick reminder from high school (just two formulae, please bear with me): You know […] Click to continue reading this post →

Bookcases

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While the wonderful downpour carries on outside (the whole of Southern California is in the grips of a powerful storm), I’ll continue with the discussion of the re-invigoration of the study that I started a short while ago…

study project - plane
(One of my all-time favourite wood-working tools. The good old-fashioned plane. Planing a bit of wood is jolly good therapy too.)

One of the main things I envisioned, and put into my sketches, was lots of space for books. Lots. I wanted big bookcases that fit the room, and so I planned a simple but robust design that stretched them eight feet from the floor to the ceiling. Of course, I wanted to make them myself – Building them myself would be more fun and much […] Click to continue reading this post →

Lecture One

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lecture notes

So it is that time. A new semester is upon me, and a totally new course to deliver. Today was my first day back on campus after the break (at least during a regular working day).

Sunday saw me sitting down (in the newly completed study) thinking about how I was going to structure the course. This usually has me sitting with the textbook, a pen, a hand drawn calendar on a big sheet of paper, and a frown on my face trying to figure out roughly what topics I will cover, how many lectures I will devote to each, how many class worksheets (see earlier post) I might have, when the midterms will be, and so forth.

What I am teaching? Why, only one of my most favourite topics to teach in the entire […] Click to continue reading this post →

In Which I Fail Physics 101…

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… but pass it on a retake!

While quickly building an ad hoc washing line pulley assembly from a bag of hooks, eyes, and pulleys, and a 2×4, I put this together at first (blotted out some background for privacy of myself and neighbours – click for larger view):

bad design

Huh. Does not want to hang level. Why? A tenth of a second after the thought, I burst out laughing loudly at my error. Ironic since I love teaching about pulleys in basic physics, and for some reason students are scared of pulleys. (Not as scared as they are of torque (why?), but scared nonetheless. I try to help them overcome those fears.) I made an obvious mistake. (Do you see it?)
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A Retreat

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sketches for studyAs I get older and busier, I seem to increasingly value quiet spaces. I always loved them, but now they seem more vital to me than ever. So I seek them out constantly. It’s important to note that it is, as they say, all relative. My whole house is a quiet space in a quiet part of a neighbourhood, which is itself in a relatively quiet part of the city. Nevertheless, I’ve been monitoring my working patterns of late and noticed quite a bit of fragmentation, which bothers me a lot. Sure, a lot of it is self-inflicted (email, blogging, and so forth can always be managed better – that’s another issue to discuss), but some of it has to do with finding good spaces to work, depending upon the type of mood and type of work to hand.

I’ve lots of favourites, and many of them are cafes and bars around the city, some places on campus (my office is not high on that list though), the odd bench in a park here and there, and so forth. But those are mostly for working in my “public space” mode. Sometimes I want to work in a different mode, or sometimes I want to just stay […] Click to continue reading this post →

’Twas the Night Before Finals…

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My always-ignored advice to anyone studying for exams is that the best thing you can do the night before is get a good night’s sleep. Long study periods long before the previous night should have been used to build up your skills and knowledge. Late-night cramming at the expense of being fresh and having your wits about you in the morning is not really going to help much, if at all. (Heh… long study periods….call me old-fashioned.)

On this very matter, Yvette (one of our regular commenters here) has outdone herself once again with her literary skills! Here is part of her seasonal (as in finals season) poem:

The Night Before Finals

By Yvette Cendes

T’was the night before finals
And all through the dorm
Crazed cramming and panic
Was quite the norm.

The students were restless
And none touched their beds
While theorems and formulas
Danced in their heads.

With textbook in hand […]

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Finally

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Well, it’s been a crazy week here in my corner of the universe. I’m still trying to find the time to break off from several things in order to update you on things from last week and the week before. Meanwhile, new things have this way of happening anyway, and sometimes I’d like to mention them too. So it is with teaching matters. Two Fridays ago was the last lecture of my electricity and magnetism class. We’d done magnetization, they’d waded through another couple of class worksheets I prepared for them on the topic, we’d remarked upon similarities and differences with respect to polarization in the electric case, and with a few hints about what phenomena were to come when they do electrodynamics (the second part of the course – we’d strictly been dealing with statics) a feeling of some sadness came over me as I said the last words of the class. I’d liked this group. They got it. I was going to take them out of their comfort zone and get them to work a bit harder and stretch themselves a bit harder, and the benefits (I hope) became apparent to them when they could see further, run faster, and jump higher (with respect to their abilities as physicists, I mean). (See some earlier thoughts on that here, as I prepared to start teaching the class.) They responded well by not whining about the extra effort required, but instead rolling up their sleeves and having a go, with good humour, a good sense of camaraderie, and remaining reasonably engaged and interactive right down to the very last lecture. They got it. I love it when that happens.

electricity and magnetism physics 408a final exam.

Monday of this week was really the end – they had their final exam (see photos above -[…] Click to continue reading this post →

My Work Here is Done

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lexington visit Yep. All done. Sitting in great cafe with a cup of camomile, listening to one of my favourite Mingus albums on the cafe’s overhead speakers, feeling that it all went well. (The latter – Mingus in a great cafe late at night? – is not really the Kentucky I remember.) I seem to have gone three for three. Class, seminar, colloquium. No disasters, besides skimping on the sleep a bit here and there and writing some of the material at the last minute. Good.

So I gave the seminar at noon, talking about much the same material I did in my Santa Barbara talk I mentioned before here. We then went to lunch at a Korean place nearby that was rather good. I ordered the bi bim bap (as I often do at Korean places) and to my disappointment, it did not come in the super high temperature near-molten […] Click to continue reading this post →