Strings Talks

20140627-080640-29200119.jpgThe conference is really rather good, with a varied program involving topics and speakers from all over the map. This includes the parallel sessions we had on Wednesday, which were held down at the Institute. Those were a lot of fun, because of the dodging back and forth between different auditoria at the IAS to get to talks of interest. I was chairing one of the sessions, and so did not get to dodge about in the first 90 minutes, and had to miss some interesting talks, but did a little talk-surfing in the second 90 after the break.

It has been many years ago now since I began to talk about there being a need for parallel sessions at strings conferences. Some people would object to them, saying that it would somehow be damaging to the field’s connected nature, where everyone is following many strands and topics in the field. To me that concern was always balanced by the problem of only having a small cluster of people and ideas represented each year due to the constraints of only having five days to present the activity of such a diverse population of researchers in the field. The main objection to having parallel sessions were, to my mind, based on a view of the field left over from when the field was smaller in terms of both people and thriving ideas. I think the conference organizers this year found a way of combining the two models rather well, with the single afternoon of parallel sessions, along with well chosen sets of half hour talks for the main sessions where we all sit together, roughly grouped by themes. There were three one hour big marquee plenary/summary talks. Theses are really useful. If I were to make a change, I’d perhaps have four or five of those, putting the two half hour talks that were displaced into the parallel section.

There is a two hour session of “Vision Talks” this afternoon. Should be interesting to hear what is said. We will perhaps get some good discussion going about where various ideas may be headed. I hope there is a lot of audience participation.

Poster sessions and the “gong show” were also great things to have as part of Click to continue reading this post

Small World

I’ve been looking at some of the many changes to Princeton, as I get the chance between sessions at the conference. A significant one for me is that Small World Coffee has really thrived and grown significantly. I can’t over emphasize how big a deal the place was to the lives of many in Princeton when it opened in 1993. Believe it or not, there was no real cafe in Princeton when I arrived the year before. The arrival of small world was a huge deal. It meant not just decent coffee, but a gathering place, a place to hang out, and a little art and performance space. Such places existed before, but on campus, and mostly for the benefit 20140625-075311-28391849.jpgof the student population. I was not a student at Princeton, although many of my friends were, so although I went to such places as well it was nice to be in a cafe that was part of the actual community that was the town of Princeton. Several postdocs loved that the place opened, and we went there a lot. Perhaps it helped balance out the ratio of trips up to New York to choosing to stay in town… Ok, just a little bit, but a significant amount. I remember my friend (and fellow IAS postdoc and neighbour at the time), Marc Kamionkowski, playing his saxophone there (sometimes putting on his “Cat in the Hat” hat for a number – he may not forgive me for mentioning this), and I’d go along to support him.

I sat there yesterday and was pleased that the expanded seating at the back meant lots of nice vistas from which I could look at other patrons without being Click to continue reading this post

Strings 2014 and a Return

20140623-114053-42053836.jpgToday is day one of Strings 2014, this year’s version of the official annual conference about the latest research in string theory. There’s a feeling that there is a buzz of excitement in the air, in part because (I’m guessing): (1) Well, it is the annual conference, you’re going to find out more about what’s been going on in the various corners of the field, and (2) everywhere you look there walks a giant of the field, and (3) more generally, people just like you who “get you”, and whose papers you’ve read that you’ve spent a good portion of your life thinking about, so it would be odd if you were not excited, and (4) it is in Princeton, which is sort of equal to Mount Olympus in our field, where a lot of the giants live, if you’ll permit me to mix metaphors a bit, and (5) apparently this is the largest Strings meeting since Paris in 2004. (I’ve heard that it is maybe 600 people registered, making it the biggest Strings ever?… Not sure.)

I could go on guessing about the buzz felt by others, but instead I’ll mention Click to continue reading this post

Magazine Practice

magazine_sketch_16_06_2014_smallAs a way of degaussing from the heat of physics research involved in producing the recent paper, I spent a bit of time getting my hand back into some proper drawing shape… I looked into some magazines and catalogues for interesting faces and found a couple.

magazine_sketch_18_06_2014_smallThe woman was done more or less directly in ink, which is a good challenge for the eye – you must be sure about a line before you put it down, since you’ve not got a second chance. A day or two later I sat in a cafe after a visit to a garden centre to pick up some supplies, to draw another interesting face I found (in a gardening catalogue). This was done more carefully, starting by doing a quick pencil sketch first for accurate layout, and then doing ink afterwards. Since people are sometimes curious about process, I include below a sequence of stages on this one as well. Enjoy.

Click to continue reading this post

Song for My Father, and for Horace Silver

horace_silver

On occasion I play this, one of my favourite songs, for my father, who passed away a few years ago. I’ll play it (“Song for My Father”) again for him, but now also for the composer/pianist who wrote it, Horace Silver, who died today. Thanks for the wonderful music.

This longer live version from a concert on Danish television in 1968. Horace Silver – Piano; Bill Hardman – Trumpet; Bennie Maupin – Tenor; John Williams – Bass; Billy Cobham – Drums: (Click below or here for the video embed – the still above comes from it.)

Click to continue reading this post

Swoosh!

swooshWell, I sort of disappeared there for about a week. I got lost in some really interesting physics and had a lot of fun doing it.

I kept walking away, and it kept bringing me back. There’s that fun groove one can get into that other theorists will recognise: You hit an interesting vein where you can calculate interesting results in a particular model, and you just can’t help yourself computing more and more Click to continue reading this post

Stockpiling Notebooks

notebook_supplyAs you know from my writings and sketches, I like to carry a notebook. People often ask me what types I use, or assume that I use the (increasingly fashionable) Moleskine books. I like Moleskine books (the little 3inx5in ones for example), and have used them a lot in the past, but actually I prefer the books by HandBook Journal Co., (made by Global Art Materials). The surface of the paper is more flexible, in my opinion. It has a little more tooth than standard Moleskine, which makes mark-making with pencil much surer, and it also takes wetting better,airline_sketches_9th_july_2013 so you can work with a little wetness as well, such as lots of ink, or watercolour (paint- or pencil-based). That allows for crisp drawings like the one on the right (click for larger view – more about these sketches here), right alongside physics research musings and computations in pen and ink line on the pages shown below on the left (those notes pertain to the paper I discussed here.)

I tend to carry one of the 8.25inx5.5in landscape ones (although I love the 5.5in square ones too). (See more chat about them here.) They allow a good Click to continue reading this post

Honest Time Travel?

On Tuesday I hung out with some of the Screen Junkies folks who you may know from the hilarious “Honest Movie Trailers” web series (seriously, if you’ve not seen any of them, please go right now and have a look). We had a fun chat about time travel in movies, and presenter Hal Rudnick and I bonded over various movies old and new. The final version of the show is up on YouTube (embed below), and I’m bummed that I did not get to meet the other guest, Christina Heinlein (JPL), who seems fun – and is a descendant of, yes, that Heinlein. I love the idea that she works at JPL, helping make possible the space exploration that Robert Heinlein helped inspire us all about in his writing. Anyway, enjoy the short piece (I wish you could see a bunch of the other material too… we really had a great chat about the ins and outs of time travel, but a lot of it inevitably ended up not making the cut…)

I could not resist talking about my view of this (perhaps growing) trend of using time travel as a means of resetting movie franchises (see Star Trek, X-Men…). It’s a great way of repairing writing and other filmmaking wrong turns. Feel free to imagine your own version of this – Star Wars anyone? Another pass at Click to continue reading this post

How I Sometimes Feel

tar_pits_entrapment_eventIn fact, the last several days have felt like this, with regards big decisions about various administrative roles I’ve been asked to consider taking on. It never seems to end, and I am terrible at saying no to as many things as I should. And I have a bad habit of doing things to the best of my ability and hence I get a reputation as the guy to ask to do a task since I did a good job last time, and so it gets me sucked in deeper into the administrative quagmire, and so on and so forth.

Rather like the “entrapment events” that happened in the La Brea Tar Pits so long ago (have a read of what I wrote about those on a field trip to the Page Museum a while back). I was wandering around the LACMA and Tar Pits grounds yesterday evening after a shoot for a show (a fun thing coming that I’ll let you know about shortly) and made a phone call to say, after ten days of Click to continue reading this post

Bent Cog

bent_cog_bromptonHere’s what almost ruined my morning on Monday. I decided to cycle the Brompton all the way into work, and went a different way as a change of scenery. At some point, my bike chain started making quite the racket, with a jarring action as I pedalled, but there was nothing visible wrong with the chain, and the gears seemed to be working just fine in terms of shifting – but the problem persists in all gears: The chain keeps trying to jump off the rear wheel every few inches, and then pops back on again. I could not see the problem at all, and I had to get into work for a meeting. My working theory was that I’d stretched the chain somehow so that it no longer fits the bike, but none of the tools I had were going to be able to help with that.

Happily, that different way I’d chosen meant that I could struggle on for a bit longer (enough to get me out of traffic, and do a bit of coasting when I could) and then walk the Brompton over from the end of Virgil to the subway stop at Wilshire and Vermont and complete my journey using the Red and Expo lines.

When I got it home, I put the bike on the high stand, and did a bit of investigation with the better visibility, and there it was. Bizarrely, the larger of Click to continue reading this post

Thank You, Maya Angelou

maya_angelouI heard this morning that she passed away today. I’m very sad about this, but also so very happy to have heard and read her work, a real lasting and and sustaining gift. I still remember the chills I felt when first hearing her read “Still I rise”. I’m quite sure that you’ll be seeing it reproduced all over the place in the next day or two… And I don’t feel any shame in following suit, so find it below. I’ve also included below an embed of a film of her reciting/performing it many years after its publication. It’s an even sweeter version in some ways. And here is a piece from the New York Times.

So thank you for embodying and encapsulating Hope so wonderfully, Maya Angelou:

Click to continue reading this post

Sketchy Freedom

downtown_towers_26_05_2014Memorial Day – 26th May 2014. I arrive at downtown Los Angeles to enjoy a few moments of the pure joy of looking. Of seeing something in front of me well enough to make a rough representation of it on a piece of paper in front of me, for the pure hell of it. This is the essence of sketching. It is about seeing. I’m looking for the… something.

My hunt is over. I see the scene I want, just off the Water Court, a few minutes from the top of the (closed) Angel’s Flight rail. The sunlight is streaming through the portal framed by the two closest buildings. The further ones make sharp geometry against the 4:00pm sky. I’m also curious to try some new coloured pens, and I like that each building suggests a different colour. I’ve got about 15 minutes before I have to leave to pick someone up.

I sit. I start. Immediately I see the guard see me from across the way, and within a minute or two he is by my side, standing in front of me. He has the “You’re not allowed to do X” look on his face, but he’s trying to start out well. I’ve had this before, right in this public space, when a guard decided that I should not take photos of the buildings. Despite all the other tourists who do so. He begins:

You know, usually we… Are you an architecture student?

Excuse me?

Are you an architecture student?

Well, what are you asking me, really?

Are you an architecture student?

Click to continue reading this post

News From the Front XII: The Nuts and Bolts of Enthalpy in Quantum Gravity

So it happened again. I got musing to myself about something and decided to do a quick computation to check it out, and it took me down an interesting rabbit hole, which resulted in me writing a nice little paper at the end of last week that appeared today on the arxiv. I think the physics is really really nice. Let me tell you a bit about it. It is in the same area of ideas that I mentioned last time, concerning that paper I wrote last month. So let me pick up the story there, since I did not really touch on the core of the story. [Note: for non-experts, the following will get somewhat technical and full of terms and ideas that I will not explain. Sorry.]

One of the things that might have struck you (if you’re an expert in the area) from my proposal to make heat engines out of black holes that do real mechanical work like the engines you read about in physics textbooks is that there ought to be no actual mechanical work since there’s no pistons – no pistons changing volumes and so forth. That is (or rather, was) a missing ingredient in the standard thermodynamics of black holes in quantum gravity. Well, that all changed a short few years ago with the work of a number of authors, particularly with the clear suggestion of David Kastor, Sourya Ray, and Jennie Traschen, and work by Brian Dolan, with a fair bit of followup investigations by various other authors including some I’ll mention below. (Update: Two reviews, with different foci, can be found in here and here.) The general idea is that if you allow the cosmological constant \Lambda to be a thermodynamical variable as well (and there is a long history of authors considering this in various contexts), where it naturally acts like a pressure p = -\Lambda/8\pi G, (G is Newton’s constant, and I’m setting various other constants to unity in the usual way) then you naturally include a conjugate to that variable that should be the pressure.

For a simple static black hole like Schwarzschild, the volume turns out to the the naive volume you get by taking the radius of the black hole and forming Click to continue reading this post

Making Marks

Been a while since I got to do some sketching. It is good practice to try to do something every day, but that fell by the wayside a little as far as proper sketches went. It has been busy the last week and a bit, and my subway time has been during very busy times when there’s not enough space to get out pen and paper and sketch a person without becoming a spectacle… and during the moments where I might have caught something, I’ve actually been calculating – working out questions for the final exam in the General Relativity class, and (more recently) doing some computations for a paper I’ll tell you about shortly.

Anyway, when time is short, I sometimes like doing quick sketches with a thicker pen. Stops me from digging into the details too much. In fact, I’m really liking that as a sketch mode these days… You make your lines boldly and you’re stuck with your choices, and so it gets you thinking about what’s globally important carefully before jumping in.

montage_of_marker_drawings_05_2014

It is great and satisfyingly distracting fun. Anyway, between this and that over the last day or two I did a few quick faces based on some photos I found in a Click to continue reading this post

A New Shower!

Camelopardalids_2014-Radiant_HD1….Let’s hope it is not equipped with a low-flow shower head though. If you get a chance this evening, find a wide area of sky away from as many lights as you can (it does not have to be perfectly dark, but the darker the better). There is a new meteor shower, the Camelopardalids…. It is new because the comet debris responsible (we’re flying through debris left over from its tail) has not intersected with our orbit before, but things have been changing a bit (apparently due to Jupiter’s gravitational pull) and as a result we’ll go right through it for the first time (as far as records show). It is expected that there’s a good chance that it will be a high event shower, and it has also been said – I forgot where I read this – that the Click to continue reading this post

Commencement Capers…

bromptons_and_robesIt is Commencement day today at USC! In celebration of that I thought I’d post a picture of my colleague Krzysztof Pilch and I, being a bit silly. We each have one of those excellently practical Brompton bikes (splendidly finished in British racing green, of course) you sometimes have read about here, and Krzysztof suggested that we take a picture or two of us in academic robes riding our bikes. Krzysztof had his academic full gear ready because he was going to go to the hooding of one of his graduating PhD students, but I had no regalia to hand since I was not planning to do anything ceremonial this year. However, I have a master’s gown at home from the old days of being a member of University College at Durham University (I’d have it ready in case I was going to high table dining at the Castle, where that College is), so I brought it in, borrowed a mortar thingamabob (from our colleague Vitaly Kresin, who also took the photos – thanks!), and we were ready for our close up! (I’d forgotten that my gown was designed to go over long-sleeved garments, so it looks a bit odd, but given that temperatures have been passing 100% these last few days, I think it was actually appropriate to be short-sleeved…)

Congratulations to all the graduating students and their families, and good luck for the future!

-cvj

Shade Emergency!

Well, making it was a bit like a Lego project, and so… fun! Basically, it is ridiculously hot here. The last couple of days have been over 100 degrees Fahrenheit and there are more days of this sort to come. This is not pleasant, in my view. I tend to operate very poorly at such temperatures, and the sun is oppressively hot, feeling like it is hammering on your head, neck, any exposed areas. (We had a wave of this sort a few weeks ago too, which resulted in a new investments in a new shape of hat.)

My main concern however is the various plants in the garden. The planting of Summer crops this year was quite late (largely because the Winter crops were slow to develop due to lack of Winter rain) and so they are still at the delicate stage where a day or two of strong hot sunlight can destroy them completely. No amount of watering can save them from this sun. So I decided to make some shades to reduce the amount of sun on various plants in the garden and on the patio. The idea was to make a nice geometrical shape that allows the plants to be nicely displayed while at the same time protecting them from that mid-morning to mid-afternoon hammering heat that I’ve seen burning the leaves on several plants. I put together a prototype design, and you can see the steps in the photos: Click to continue reading this post

Advice at Graduation

It is Commencement on Friday, here at USC. Thousands of students will be dressing up in gowns and taking part of the ceremonies marking the ending of their time here at USC and the beginning of the rest of their lives. It’s an exciting time.

Merrill Balassone and a team from USC Media Relations came by my office a few weeks ago to take 15-20 minutes of time to do a prototype of a project on this very subject of commencement. The result was fun, and apparently they used it to build onto in order to make the final short video you can see below. advice_film_stillThey did a great job! It is a group of USC professors and staff** giving brief thoughts to graduating students upon their graduation. You’ll maybe guess what I say in my segment. It is a theme I mention here a lot, as part of my personal war on people being shut out of (or shutting themselves out of) participation in aspects of our society.

The summary of the piece is here and the YouTube video is embedded below: Click to continue reading this post

Metro Goes for All the Science Tropes

science_metro_poster I think the people at LA Metro were trying to go for all of the visual science tropes in one cliché-filled glance! I’m a big fan of LA Metro, as you know from several posts about it here, so don’t misunderstand my poking fun at their ad I spotted on a bus stop bench. I think it is to do with helpful apps for your phone – presumably they help you use the system more easily, because of…science? More generally, I’d love to believe that people will take the train more because scientists are involved in designing the logistics, but there’s so much evidence against this on both counts, like having the Blue line and the Expo line – that share the same main platform – both boast BLUE as their colours. But put that all aside for now, and let’s simply count off all the sure-fire imagery that will Click to continue reading this post

Old School Writer

posting_stuff…Yeah. Somehow sending proposals and samples of manuscripts around by email does not really feel super-exciting to me. But it is the way things are done now, it seems. But this afternoon, I found myself doing something very old-school, which I rather enjoyed, perhaps because it connected me with writers through the ages: Printing up some special packages (proposal, samples, etc, of the book project), putting them into envelopes and schlepping them down to the post office, getting in line, and Click to continue reading this post

That Time of Year

jacaranda_april_2014Well, it is that time of year. The Jacarandas peaking is one of the many LA markers of the seasons for me. It means that classes will soon be over (in fact they are now) and I’ll be saying goodbye to a group of students, either because a class is over, or because students I’ve taught in earlier classes are graduating and leaving USC. Either way, it is always a time of mixed feelings, and a sense of being in transition in a number of ways. The Spring is already beginning to feel like it is rolling into Summer, and I’m clearing my desk of one set of things and making way for other things.

(Oh, and of course, the other thing that happens this year is that I seem to end up doing a post like this at around this time, right down to within a few days. It usually involves a picture of a Jacaranda tree. See here and look at the list of related posts below.)

I had an extraordinarily good group of students in my Spring class this year. As you may recall it was an undergraduate General Relativity class (see earlier posts on this by searching on that topic). We ended up having a lot of fun with the topic itself, and things were extra good because the students were very Click to continue reading this post

When Stars Go Bang…

I learned* that over on the Huffington Post, Christian Ott (Caltech) wrote a piece describing research on modelling stellar explosions using supercomputers. When a star goes supernova, what exactly happens? Capturing the physics that goes on is a very difficult problem to do, and in the article he explains some of the difficulties, and some of the recent progress.

There’s a slide show showing some of the results of simulations that have been done of the fully three-dimensional problem, and a little movie that puts it all together.

Enjoy!

-cvj

*Thanks Crystal D.!

Another Engine

world_engineThis diagram is the cycle for another heat engine (using a black hole as the working substance) that I studied in the recent paper. It is a path made of two constant pressure legs (isobars) and two constant volume legs (isochores) that happen (due to the properties of static black holes) to also be adiabats. See the post.

It got included in the paper as another example where one could compactly write down something useful about the efficiency, since, as it turns out, you can write closed form expressions Click to continue reading this post

Morning Portrait

morning_portrait_27_04_2014_smallAs a contrast to yesterday’s quick caricature effort, I went back to one of the pictures in the magazine and did a more careful pencil sketch. Very different kind of exercise and technique needed to coax out the things I wanted to bring forward. It is a scan of pencils, so beware that it is not as representative of what’s on the page in some ways. To add to that I really should do a lot more finish work on this one (rendering of shadows on Click to continue reading this post

Debate about Forever…

This is a good one from the Onion. (I’ve not looked in on them for a while, so this was a funny thing to return to see…*) The title says it all: “Top Theoretical Physicists, R&B Singers Meet To Debate Meaning Of Forever”. Extract:

[...] at the four-day symposium, where they grappled with extant questions regarding the concept of forever that remained unresolved, such as whether forever is better conceived as an infinite, four-dimensional expanse of space-time or, rather, what one second feels like when you’re away from your girl.

“For many years, the R&B community has posited the classic notion that forever is presumed to go on and on like our love,” said Edward Witten, a string theorist at the Institute for Advanced Study, who acknowledged that while time appears to extend unendingly, it is paradoxically composed of discrete moments such as a tender embrace or a single perfect kiss. “This assertion then raises a problem of even greater [...]

More here.

-cvj

*Thanks aef!

Morning Caricatures

morning_caricatures_26_04_2014_smallLovely bit of sitting in the sun for a short while after breakfast this morning relaxing by doing some quick freehand sketches from pictures in a magazine. I was experimenting with a pen I love but don’t use much at all – One of those nice inky brush pens by Pentel. Gives some interesting lines that take some getting used to since it is quite a different mark-making tool than the pens I Click to continue reading this post

A Monday Interview

On Monday 28th April at 8 PM Eastern time (5 PM Pacific) I’ll take part in a live radio interview that you might want to listen to, on a show called Alpha Centauri and Beyond. I guess I’m in the “Beyond” bit? I don’t really know anything about the show except that they like to bring people on to discuss ideas, and when I get a call to come and help sprinkle a bit of science, you know I’m likely to say yes if I can spare the time.

You can see a link to the details here, and you can listen online. As you can see it is advertised as being about me explaining string theory. Well of course that billing is nothing to do with me – I can’t hope to explain any complicated subject like that in the time available – but if asked I will do my best to try and motivate some of the ideas behind the subject. I hope it will be a fun interview and that we will explore a number of interesting topics, and not just talk all the time about string theory, since that could be rather dull, and definitely a missed opportunity… There is so much more to talk about!

Tune in and listen to find out!

See you then.

-cvj