Hello from the Aspen Center for Physics. One of the things I wanted to point out to you last month was the 74 questions that Andy Strominger put on the slides of his talk in the last session of the Strings 2014 conference (which, you may recall from earlier posts, I attended). This was one of the “Vision Talks” that ended the sessions, where a number of speakers gave some overview thoughts about work in the field at large.
Andy focused mostly on progress in quantum gravity matters in string theory, and was quite upbeat. He declines (wisely) to make predictions about where the field might be going, instead pointing out (not for the first time) that if you look at the things we’ve made progress on in the last N years, most (if not all) of those things would not have been on anyone’s list of predictions N years ago. (He gave a specific value for N, I just can’t recall what it is, but it does not matter.)
He sent an email to everyone who was either speaking, organising, moderating a session or similarly involved in the conference, asking them to send, off the [...] Click to continue reading this post
… in my own book! This is one of the more amusing emails I’ve received in recent days. Apparently there is no algorithm that checks you are not recommending to an author a copy of their own book.
And no, I’ve no idea why this version is so expensive. Did they print this one with gold leaf illumination on the first letter of each chapter?
-cvj Click to continue reading this post
I was sent an interesting link a while ago* that I thought I would share with you. It is a really good discussion about Dark Energy – what do we think it is, why we think it exists, why some think it does not, and how to move forward with the discussion of what is, after all apparently *most* of our universe. It is a panel discussion that was hosted by the Institute for Arts and Ideas (which I *love* the idea of!). The discussion is described on the site as follows:
Dark energy is supposed to make up two-thirds of the universe. But troublingly CERN has yet to find any evidence. Have we got our story of the universe wrong – might dark energy be the aether of our time? Do we need a new account of the universe, or is it too soon for such radical solutions?
The BBC’s Sue Nelson asks Templeton Prize winning cosmologist George Ellis, Cambridge physicist David Tong and mathematician Peter Cameron to seek the invisible.
Ok, the “troublingly CERN has yet to find any evidence” part puzzles me a bit, since nobody’s really expecting CERN to find any evidence of it, in any large scale experiments that I’m aware of (please correct me if I am wrong)… Is the writer of the abstract confusing Dark Energy and Dark Matter? Even then I think it is an odd phrase to lead with, especially if you don’t mention the huge amount of evidence from astronomy in the same footing… but I imagine the abstract was maybe not written by a physicist?
Nevertheless, I strongly recommend it as a thought-provoking discussion, and you can find it embedded below. Do also check out their many other interesting [...] Click to continue reading this post
Sorry for being a bit quiet the last week. I’ve ben working hard on a project and a lot of other things, and got snowed under. One of the things that has kept me busy has been the garden, and I am getting good rewards for my efforts. More later.
The fig trees have begun their production of fruit, even after being [...] Click to continue reading this post
It is the 4th of July, and I hope you who are celebrating it have a good time today!
I can’t really let the day pass without sharing with you the episode of Fail Lab in which we examine fireworks and pyrotechnics with an appropriate cautionary note, and a dash of humour. Enjoy it again if you’ve seen it before, and don’t forget to check out all twelve episodes. You can read my discussion of the whole series (excellently made by Patrick Scott) starting here, and there’s more here. Click below for the episode: [...] Click to continue reading this post
Yep. This is an exciting new discovery for me. No, it is not what you think! I’m talking about gardening matters. It seems that a lot of my cucumber and squash plants are not producing a great deal this year, (with several small squashes not developing much before falling off) and I could not figure out why. On the other hand, I’ve done a better job of building sun shields for them, to stop them being fried by the intense heat over the course of a hot day. I now think that maybe these things are connected. First of all, I’m not seeing a lot of bees of any sort in the garden, and so I wonder if it is simply that there’s not a lot of pollination going on. Couple this with the fact that the sunscreens (some quite low) are probably hiding them from some bees that might be passing by, I’ve begun to wonder if it is time to help things along a bit. [...] Click to continue reading this post
As you may know from three previous recent posts on research (here, here, and here), I’ve been thinking and calculating a lot in the area of dynamical cosmological constant – concerning mostly (but not entirely) thermodynamics and quantum gravity. Specifically, the cosmological constant becomes the pressure variable in the thermodynamics. I think it is important, and will teach us something about things like gauge/gravity duality, string theory, black holes, and perhaps even cosmology, but I am not sure what yet. I’ve made some suggestions in recent papers, and computed some interesting things along the way.
Anyway, the larger community has not been following this story much, since: (1) It means a break with some powerful and still very fruitful frameworks where the cosmological constant being fixed is a given – like AdS/CFT – and it is not clear what that means yet, so the motivation is not super-strong; and (2) Let’s be honest, there’s no superstar working on it, so it is not going to get anyone any points. So I’ve been trying to shout about it in my little way from the periphery, as I think it might be useful, and since several people have been doing really good and interesting work on this issue for many years and it is worth more people seeing what they’ve been up to.
So imagine my pleasant surprise when I looked on the listing of new papers on the arXiv for today and saw three (!) papers on the subject, moving things forward in various ways. (They all seem to have noticed some of what I’ve [...] Click to continue reading this post
The 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 had 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
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 of 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
Today 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
Longest day of the year? It sure felt like it. I spent about 6 hours of it standing high above the city in the sun talking about physics and astronomy to camera… Super tiring.
It is for a new show I’ll say more about later.
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A small tasty victory in the battle against powdery mildew and aphids… Yay!
-cvj Click to continue reading this post
As 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.
The 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.
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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.)
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Well, 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
As 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, 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
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
In 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
Here’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
I 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:
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Memorial 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 sun 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?
Are you an architecture student?
Well, what are you asking me, really?
Are you an architecture student? [...] Click to continue reading this post
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 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 , (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
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.
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
….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
The Road goes ever on and on
Down from the door where it began.
Now far ahead the Road has gone,
And I must follow, if I can,
Pursuing it with eager feet,
Until it joins some larger way,
Where many paths and errands meet.
And whither then? I cannot say.
- J.R.R. Tolkien.
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It 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 [...] Click to continue reading this post
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
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. They 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
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
…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