Exam Heat

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We had a midterm in the undergraduate General Relativity class this week. Midterm II. We’d just come off a batch of lectures on black holes (focussing on Schwarzschild and Kerr), and so it seemed very natural to focus on that as the topic. Schwarzschild is the most basic (vanilla) black hole and Kerr is the case of having rotation for a bit of extra flavour. They are both hugely important in real physics – the former for the basic phenomena and then the latter since most objects out there in the astrophysical realm are actually going to be rotating to some degree (and after gravitational collapse, probably a high degree). So I focussed on those in class.

Screen Shot 2014-04-11 at 14.45.37For the midterm therefore, I got the opportunity to have them discover properties of the (less astrophysically important perhaps) charged black hole – the Reissner-Nordstrøm solution*:
[tex] ds^2=-\left(1-\frac{2M}{r}+\frac{Q^2}{r^2}\right)dt^2+\left(1-\frac{2M}{r}+\frac{Q^2}{r^2}\right)^{-1}dr^2+r^2\left(d\theta^2+\sin^2\theta d\phi^2\right)\ ,[/tex]

…and do a few computations with it analogous to what they did for the other cases in class and in homework. I hope they had fun (like discovering that for a Click to continue reading this post →

Festival of Books and CicLAvia

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public crossword at festival of booksBy the way, for those of you in the area, don’t forget that the LA Times Festival of Books comes to the USC campus again this month. It is next week – the 12th and 13th April. The book prizes ceremony is the night before, as usual. on the 11th, and as usual there is an interesting selection of finalists in various categories that you can see online here, for example.

(Happily, there is no clash with a CicLAvia this year! – You might remember the craziness last year – The next Ciclavia is this coming Sunday, the 6th, and it is along Wilshire again. Sadly, I will not be able to attend since I must be away on a trip and do not return until the afternoon on Sunday, leaving little time to get on my bike and get down there. Do head there and enjoy it… the Wilshire route is particularly nice.)

The main Book Festival website has a lot of information up about what is Click to continue reading this post →

Major Honours

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On Friday I had to give the keynote address at the Phi Beta Kappa induction ceremony held here on the USC campus. I did not know what that really was when asked, perhaps because my educational environment as a student was in the UK. (Although for all I know there are such things over there too, but perhaps I did not notice.) After a bit of googling I learned that this is an honours society and it is devoted to excellence in the liberal arts. It is the oldest one of its sort, apparently (founded in 1776), and these days although science was there at the start, the practice is to add “and sciences” when you say liberal arts now. Students who maintain a certain standard of grades through their undergraduate degree in a liberal arts and sciences area are invited to 20140401-093450.jpgbecome members and then there is an induction ceremony. Sadly, no secret handshakes and strange behind the closed doors practices… Well, as far as I know. (In fact, as a thank you for giving the address, I get added to the membership as an honorary member, so perhaps a packet will arrive with my instructions about handshakes and so forth, but I doubt it.)

My speech was to be something about the liberal arts and to celebrate that and to impart some wisdom to the students and their assembled parents and so forth. I was happy to oblige and after letting it stew in background in my head for some time, come Friday morning I sat down at the computer and something nice flowed out through my fingers onto the page. People liked it – a lot, I was later told. I’m still a bit surprised (pleasantly) by that. There may be a story about it later, so I’ll post a link to that when/if it appears.

To my delight I recognised several names in the list for the ceremony. There were in fact five physics majors inducted (is that the right word?) all at the Click to continue reading this post →

Talking with Dinosaurs

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20140401-095516.jpgThursday’s event at the Natural History Museum went very well. There was a great turnout, and the audience was very enthusiastic. As you can see from the photos*, there were two fierce-looking large dinosaurs in attendance in the audience, but it did not have any effect on the overall time-keeping, and the lectures ran over the allotted time quite a bit.

But people had fun, and the museum staff were very kind and flexible, so that’s ok. I actually learned a lot from Ed Krupp’s talk about the astronomy and astronomical objects along the Silk Road from the Far East to the Middle East especially. Laura Danly gave a talk that was mostly a detailed history the Internet including at least three internet cat videos as illustration (an emphasis that I found unexpected, I’ll admit, since I was expecting more about contemporary astronomy). It was certainly a modern perspective on the Silk Road, as we promised the audience, and it seemed to go down well. The observation opportunity that Laura arranged outside (with the telescopes that were set up in the new gardens) was also well received. Jupiter and its Click to continue reading this post →

The Calculus of Gender and Sexuality?

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So, I don’t know why, but in addition to the catalogues I get in my work mailbox from publishers of physics books or lab equipment, I’ve started getting a lot about books in the Humanities and related subjects. Is this because those publishers know of my tendency to dabble in other subject? I’ve no idea. In any case, all of those things tend to end up pretty swiftly in the recycling bin nearest the department mailboxes. A suite of lovely new books on teaching Art History is about as valuable to me as a shiny sets of vacuum pumps or electronic controllers. I’ll admit to sometimes looking through and longing for the time I’d need in order to explore such things (vacuum pumps or Art History texts)… but then into the bin they go.

Well, earlier this week a catalogue arrived and one might be forgiven for thinking that they are really trying to get my attention with this one. It is a catalogue of Gender and Sexuality texts from Ashgate, and if the image on the cover is representative (uh, as far as I know it is not!) they’ve really developed some fancy techniques in the field!

Some of the formulae are hilarious! (And I’m trying to understand the, obviously important, inequality right in the middle…)
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Under Silk Road Skies

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I’m doing a disturbing amount of speechifyin’ this month. One of the occasions is tomorrow, and is open to the general public. Have you been to the Natural History Museum’s “Traveling the Silk Road” exhibition yet? I went to have a look a couple of days ago and it is rather nice. I recommend it. There are even live silk worms!

griffith observatory city view at nightI’ve been coorganizing an event as part of their series of lectures that accompanies the event and I am delighted to announce that I have connected two of the most awesome spaces and institutions in the city for this one. The Griffith Observatory will team up with the Natural History Museum for this one, with a lecture and Q+A session, and then (weather permitting) a bit of stargazing in the new gardens! Please spread the word and come along:
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Discovery Coincidence

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chatter_sketch_arenaSome of you are wondering what I’m working on while on retreat. Well, actually there’s a nice coincidence here. I’m working on the graphic book that you may have heard me talk about a bit. “The Project” as I sometimes call it. I’ve been doing things on various aspects of it, such as reworking the description of it for various people to look at, writing new bits, and spending a bit of time pulling together various bits of the prototype story I used to start all of this back in 2010. The prototype bits have all of my experimentation and development of style and technique all over them, and so there are pages that needed a bit of rework (to say the least). So, on Monday, Click to continue reading this post →

Around Fifteen

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While on a hiding retreat in another town or city, I like to seek out a local group that might be doing a “drop in and draw” session. You show up, pay your money, and there’s a safe environment (in a studio, a back room, upstairs of a pub, etc) for a model and artists to work on the wonderful business of capturing the human form in various media. I’m a reasonably private person so I like to keep the anonymity level reasonably high, but it does not only work. People are of course on the watch out to protect the group from perceived problems, so they ask questions. Others are just trying to make friends, and so they ask questions too. I just like to be polite and friendly, share the odd joke or remark, but mostly keep my mouth shut and listen to the various small talk that breaks out during breaks. Most of all, I want to get on with the business of drawing.

sketches_17th_march_2014_smallI went to one on Monday. This time around it was sort of amusing to me at one point when one of the organisers of the group asked me why I’d come down from LA to their small seaside town drawing group and I said I was hiding. I could sense alarm immediately (I can imagine the pictures he might have had in his mind even before I said “hiding”) and so I then went further, by way of reassurance, and said something vague but standard about wanting to get out Click to continue reading this post →

Discovery Clarification

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[Update: Over the months following the announcement, doubt was cast over exactly what BICEP2 saw, and now it seems that the signal announced by BICEP2 is consistent with polarisation produced by galactic dust. See here.]

I’m actually in hiding and silence for a week. It is Spring Break and I have locked myself away in a seaside town to do some writing, as I did last year. But I must break my silence for a little while. Why? Well there’s been a really great announcement in physics today and while being very happy that it is getting a lot of press attention – and it should since the result is very important and exciting – I’ve been stunned by how confusingly it has been reported in several news reports. So I thought I’d say a few things that might help.

But first, let me acknowledge that there’s a ton of coverage out there and so I don’t need to point to any press articles. I will just point to the press release of the BICEP2 collaboration (yes, that’s what they’re called) here, and urge you once you’ve read that to follow the link within to the wealth of data (images, text, graphs, diagrams) that they provide. It’s fantastically comprehensive, so knock yourself out. The paper is here.

I keep hearing reports saying things like “Scientists have proved the Big Bang”. No. The Big Bang, while an exciting and important result for modern cosmology, is very old news. (You can tell since there’s even a TV comedy named after it.) This is not really about the Big Bang. This is about Inflation, the mechanism that made the universe expand rapidly from super-tiny scales to more macroscopic scales in fractions of a second. (I’ll say more about the “super-tiny” below).

I also hear (slightly more nuanced) reports about this being the first confirmation of Inflation . That’s a point we can argue about, but I’d say that’s not true either. We’ve had other strong clues that Inflation is correct. One of the key things that pops out of inflation is that it flattens out the curvature of universe a lot, and the various observations that have been made about the Cosmic Microwave Background over the years (the CMB is that radiation left over from when the universe was very young (about 380,000 years old – remember the universe is just under 14 billion years old!)) have shown us that the universes is remarkably flat. Another previous exciting result in modern cosmology. Today’s result isn’t the first evidence.

So what is today’s exciting news about then? The clue to the correct Click to continue reading this post →

Wormholes!

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“So, you have a choice. We’ve ten minutes of class left. I can either finish early, or…. I can show you that there’s actually a wormhole living in this picture, or can I tell you about Hawking radiation.”

wormhole_sketchThat was the choice I presented the students with after we’d spent some time together exploring the Kruskal-Szekeres extension the the basic black hole solution, in my General Relativity class today. You probably don’t know what all that is, and that’s ok. Suffice to say that you end up with a pretty diagram which looks like two everlasting black holes put together as in a sort of elegant trading card. Or perhaps a neat knot where one black hole is sort of upside down and neatly slots into the other one so that they hug each other into eternity, acting as each others’ past and future. Look it up and see.

Anyway, they went for the wormhole, with a chant “Worm-Hole! Worm-Hole!”. So I constructed the wormhole for them… the Einstein-Rosen bridge, as it is known, ending with the sad news that it is not a real traversable wormhole that Click to continue reading this post →

Science Films Galore!

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Sorry that it has taken me so long to get to posting the results of the USC Science Film Competition. It has been super-hectic. In addition to the usual things I have to do, I had to give a talk about science education to the Society of Physics Students – that went well, I heard – read and examine another PhD. thesis (twice in one week), do battle with two fronts of vermin attacks on my house, and prep a whole lot of other things I won’t trouble you with… Also, oddly, the time change seems to have left me in a state of exhaustion each day.

Enough with the excuses. What are the results, you ask? And is it true the winner was controversial?!

usc_science_film_showcase_2014_1Well, first and foremost we had a fantastic time celebrating the work of all the students in the competition. About 75 or so people turned up, making all my frantic buying of things in Trader Joe’s and so forth all worth while, and there were two screening sessions separated by a coffee and snacks break. Since there were twelve films this year (a 50% increase!) there were six per session (I curated things so that the sessions were about the same length), which worked rather well. A lot of the films used quite a bit of their 10 minute allowed duration, and so given that I pause between films to give each team a chance to take a bow, it was in danger of being a long evening, and for that I apologize to everyone, but I do think that the students should get a fair amount of individual recognition for their hard work.

Anyway, to cut a long story to medium, the standard was quite high this year, with several good films at the top that were hard to choose between, but I think the 15 judges (from academia and the film industry, with scientists and filmmakers and scientists-turned-filmmakers on both sides) got it right.

The first prize winning film has resulted in raised eyebrows from some, including the filmmakers themselves who apparently were sure that their film would be overlooked due to its content. I think that the judges got it exactly right. It is a fine example of exactly what I’m looking for in this competition- a Click to continue reading this post →

Cloudy with a chance of Physics

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I don’t know. That’s a bit of a desperate title. But in exchange, a rather nice cloud formation, don’t you think?

clouds_3_3_2014_1

This was from the sky over Los Angeles yesterday evening (a shot of the sky in the other direction is to the right – click for larger), and my first thought was “what’s the physics behind these beautiful structures?” There’s enough regularity here to expect there to be a mechanism, but I do not know what it is. Some combination of atmospheric conditions like wind speed, clouds_3_3_2014_2temperature, perhaps some layering of different bodies of air, and so forth, resulted in this and I’d love to know more. What factors set the roughly regular size of the structures, their pretty uniform distance apart, etc? (These are typical physicist’s questions, in case you’re Click to continue reading this post →