Category Archives: work

D-Brane Fun!

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image Turns out that it still a lot of fun to lecture about string theory and D-branes! (The latter are an important type of extended object, generalizing membranes, that have been very useful in theoretical physics for the last 20 years. — My goodness, it has been 20 years since Joe Polchinski first demonstrated their importance for string duality!) The students at the Latin American String School here in Mexico City seem to be very engaged and enjoying themselves. Although I was having fun I was also not without a presentation error or two brought on by […] Click to continue reading this post →

It’s Time

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delorean_sketchOk, So I’ve finished prepping my presentation of detailed recipes for how to make time machines. (Sorry, but it does not involve any of the elements depicted in the sketch above.) It is for a special event tonight celebrating the fact that this is the day Marty McFly came forward in time to in Back to the Future II. The question is: Should I really be telling people how to do this? Yikes. 😉

Ok, time to get into my flying car and head off to teach…

-cvj Click to continue reading this post →

Gravity on the Horizon!

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joshua_tree_shoot_horizon_2Had to nip over to Joshua Tree National Park yesterday, for my sins.

Why? Well, gravity, of course. I can’t tell you the full details, but I was helping out the folks from the BBC on a documentary program (for the series Horizon, which I loved watching back in the 80s when I was in school!) being made about topics connected to gravity, space travel, mass, energy, and all that good stuff.

You can see me mid-demo in the photo (click for larger view), standing upon a rock somewhere in the park, talking about Newton and Einstein. I also got to be a bit of a stunt driver for a while, being filmed bouncing an SUV along a dirt road several times, which was (I grudgingly admit) a lot of fun!

After the shoot […] Click to continue reading this post →

Screen Junkies – The Martian, Science, and Problem-Solving!

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screen_junkies_martianAs promised, the Screen Junkies episode we made is out. It is about The Martian! JPL’s Christina Heinlein (a planetary science expert) also took part, and I hope you find it interesting and thought-provoking. Maybe even funny too! As usual, there’s a lot that was said that was inevitably left on the (virtual) cutting-room floor, but a lot of good stuff made the cut. All in all, I’d say that this film (which I enjoyed a lot!) had a refreshing take on science and engineering for a big studio film, on several scores. (Remaining sentences are spoiler-free.) First, rather than hiding the slow machinations involved in problem-solving, it has a lot of it up front! It’s an actual celebration of problem-solving, part of the heart and soul of science and engineering. Second, rather than have the standard nerd stereotype […] Click to continue reading this post →

Get ready for some “movie science” chatter…

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hal_cvj_christina_bigYes, I’ve been hanging out with my Screen Junkies friends again, and this time I also got to meet JPL’s Christina Heinlein, who you may recall was in the first of the Screen Junkies “Movie Science” episodes last year. While we were both in it, I’d not got to meet her that time since our chats with host Hal Rudnick were recorded at quite different times. This time, however, schedules meant […] Click to continue reading this post →

Metals are Shiny

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“Metals are shiny.” That’s one of my favourite punchlines to end a class on electromagnetism with, and that’s what I did today. I just love bringing up a bit of everyday physics as a striking consequence of two hours worth of development on the board, and this is a good one for that. I hope the class enjoyed it as much as I did! (Basically, as you can’t see in the snapshot of my notes in the photo, those expressions are results of a computation of the […] Click to continue reading this post →

Thomas and Fermi

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thomas-fermiThe other day the Thomas-Fermi model (and its enhancements by Dirac and others) wandered across my desk (and one of my virtual blackboards as you can see in the picture) for a while. Putting aside why it showed up (perhaps I will say later on, but I cannot now), it was fun to delve for a while into some of these early attempts in quantum mechanics to try to understand approximation methods for treating fairly complicated quantum systems (like atoms of various sizes). The basic model showed up in 1927, just a year after Schrodinger’s […] Click to continue reading this post →

Rearrangements

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office_musings_2 Just thought I’d share with you a snapshot (click for larger view) of my thinking process concerning my office move. I’ve been in the same tiny box of an office for 12 years, and quite happy too. For various reasons (mostly to do with one large window with lots of light), over the years I’ve turned down offers to move to nicer digs… but recently I’ve decided to make a change (giving up some of the light) and so after much to-ing and fro-ing, it seems that we’ve settled on where I’m going to go.

Part of the process involved me walking over there (it’s an old lab space from several decades ago, hence the sink, which I want to stay) with a tape measure one day and making some notes in my notebook about the basic dimensions of some of the key things, including some of the existing […] Click to continue reading this post →

Face the Morning…

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expo_line_lady_11_sept_15With the new semester and a return to the routine of campus life comes taking the subway train regularly in the morning again, which I’m pleased to return to. It means odd characters, snippets of all sort of conversations, and – if I get a seat and a good look – the opportunity to practice a bit of quick sketching of faces. I’m slow and rusty from no recent regular practice, so I imagine that it was mostly luck that helped me get a reasonable likeness […] Click to continue reading this post →

Naked!

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negative_mass_thoughtsSnapshot of my doodles done while talking on the phone to a BBC producer about perhaps appearing in a film discussing anti-gravity*. I explained lots of things, including why General Relativity does not seem to like negative mass, partly because they have something called a “naked singularity”, which is a big problem. Only after the call ended did I recall that in 1999 I co-authored a paper in which we discovered […] Click to continue reading this post →

PBS Shoot Fun

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pbs_shoot_selfieMore adventures in communicating the awesomeness of physics! Yesterday I spent a gruelling seven hours in the sun talking about the development of various ideas in physics over the centuries for a new show (to air next year) on PBS. Interestingly, we did all of this at a spot that, in less dry times, would have been underwater. It was up at lake Piru, which, due to the drought, is far below capacity. You can see this by going to google maps, looking at the representation of its shape on the map, and then clicking the satellite picture overlay to see the much changed (and reduced) shape in recent times.

There’s an impressive dam at one end of the lake/reservoir, and I will admit that I did not resist the temptation to pull over, look at a nice view of it from the road on the way home, and say out loud “daaayuum”. An offering to the god Pun, you see.

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Turns out that there’s a wide range of wildlife, large and small, trudging around on the […] Click to continue reading this post →

Fresh Cycle

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brompton_30_08_2015I’ve been a bit quiet here the last week or so, you may have noticed. I wish I could say it was because I’ve been scribbling some amazing new physics in my notebooks, or drawing several new pages for the book, or producing some other simply measurable output, but I cannot. Instead, I can only report that it was the beginning of a new semester (and entire new academic year!) this week just gone, and this – and all the associated preparations and so forth – coincided with several other things including working on several drafts of a grant renewal proposal.

The best news of all is that my new group of students for my class (graduate electromagnetism, second part) seems like a really good and fun group, and I am looking forward to working with them. We’ve had two lectures already and they seem engaged, and eager to take part in the way I like my classes to run – interactively and investigatively. I’m looking forward to working with them over the semester.

Other things I’ve been chipping away at in preparation for the next couple of months include launching the USC science film competition (its fourth year – I skipped last year because of family leave), moving my work office (for the first time in the 12 years I’ve been here), giving some lectures at an international school, organizing a symposium in celebration of the centenary of Einstein’s General Relativity, and a number of shoots for some TV shows that might be of […] Click to continue reading this post →