Category Archives: science

So What Is String Theory, Anyway?

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The usual answer you’ll get from the person on the street (as it were) includes lots of nice words about wiggling strings that look like particles, and so forth, and that’s fine. However, the [informed] next level answer, when you’ve worked enough in the field, is that we don’t know. I’ve told you why (at least in part) in previous posts and so I’ll let you read them. We’re still working on it.

While we work, we’ve learned that it is a quite marvellous thing (from the bits of it we’ve come to grips with) that is teaching us a lot about all kinds of physics, and mathematics too. Some of this may be good for describing things about Nature, and we’re still working out lots of that (although see some of the exciting things I’ve been talking about in my previous post and the links therein).

So what do we put on the T-shirt? (You know, the analogue of Maxwell’s equations for electromagnetism – light, etc – that every physics undergrad likes to have on their T-shirt). Well, we don’t know yet.

polchinski what is string theory

But that’s all my opinion. Every now and again it is good to hear from one of the masters about what they think of string theory*, and what it is and so forth. Happily, Joe Polchinski has been known to agree to stand up and give an exposition on this […] Click to continue reading this post →

Brainstorming

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presentation preparation in the sunI had quite a marvellous brainstorming session today. You’ll recall I was preparing a presentation for the February 15th symposium at the AAAS meeting the other day. Well, all of us concerned (the four of us presenting as well as various Brookhaven staff who will take part in the symposium discussion as well) got together over the phone for a teleconference today. It took almost three hours (but happily I was sitting in the sunshine while doing it, as you can see). We wanted to chat about the distribution of ideas and results that will be presented.

There are four of us presenting at the event, with only a short time each to get across some of the key ideas and so we need to make sure that we don’t do too much […] Click to continue reading this post →

Categorically Not! – Dark Matters

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categorically not! presenters feb 1st 2009

(Categorically Not! presenters and performers on 1st Feb. 2009)

The next Categorically Not! is on Sunday February 1st. The Categorically Not! series of events that are held at the Santa Monica Art Studios, (with occasional exceptions). It’s a series – started and run by science writer K. C. Cole – of fun and informative conversations deliberately ignoring the traditional boundaries between art, science, humanities, and other subjects. I strongly encourage you to come to them if you’re in the area. Here is the website that describes past ones, and upcoming ones. See also the links at the end of the post for some announcements and descriptions (and even video) of previous events.

The theme this month is Dark Matters. Here’s the description from K C Cole:

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The Keeling Curve

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keeling curveToday on NPR’s Morning Edition they played a piece by Madeline Brand that aired in 2007 about the Keeling curve, and the man behind the curve, Charles David Keeling. As you may know, the Keeling curve (above) is a striking demonstration of the steady increase in the concentration of carbon dioxide in the atmosphere, as measured from one location (on top of Mauna Loa in Hawaii) by one very simple method over almost 50 years.

It is a lovely story of dedication and determination that resulted in a simple, striking, […] Click to continue reading this post →

Uncommon Conversations

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college commons logo smallI almost forgot to mention that tonight marks the launch of the series of events called the College Commons here at USC. Here’s a news story about the programme. This academic year, I’ve been working on the committee working on shaping the ideas that have come up from the faculty (I had promised to tell you more about this), and we’ve announced the short Spring programme, which you can see here.

There is a featured part celebrating 1859:

Where do ideas come from, and how far do they travel? One hundred and fifty years ago, the astonishing year of 1859 saw not only the publication of Charles Darwin’s The Origin of Species, but such pioneering works as John Stuart Mill’s On Liberty, Charles Dickens’s A Tale of Two Cities, Karl Marx’s Critique of Political Economy, and Richard Wagner’s first version of Tristan and Isolde. This year also marked amazing advances in travel and communications, the first battles prefiguring the Civil War and the first trapeze act performed in Paris. Can we imagine the world 150 years from now, and imagine the place our ideas will have in it? Scholars from biology, anthropology, physics, literature, history, and gender studies, as well as poets and artists, will explore these questions together this spring.

I hope there’ll be a lot of participation in the events (I’ll say more on this later). Tonight has a free movie, Master and Commander (so there’s a reason to go, right […] Click to continue reading this post →

Preparation

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Yes, I’ve been a bit quiet of late, I know. I’ve so many things on, both professional and personal that it sometimes keeps me occupied from when I wake up just before sunrise right through to falling asleep a bit after midnight. And yes I know that means I’ve been not getting the traditional full nights of sleep, but if my body insists on getting up at 5:30am, who am I to resist? I thought it was due to jetlag from the trip a couple of weeks ago, but it seems to have taken. I don’t mind too much since watching the light change as the sun rises is a marvellous way to start the day.

clifford johnson preparing slides at the boardAmong the things I’m up to (yesterday and today so far) is a strip-down-and-redesign of a short talk for an exciting symposium that is coming up in a few weeks in Chicago. The American Association for the Advancement of Science is having their big annual shindig there (apparently the biggest science conference in the world) and there will be a number of addresses, plenary talks, and keynote speakers and the like (including Al Gore, by the way), and also several sessions of symposia and other presentations on various topics.

While slightly annoyed at the fact that one major day of the conference is on Valentine’s day (which means I’ll have to be out of town on just the day that maybe, just maybe, on the off-chance, you know – if the universe sneezes or something, somebody might want me to be their Valentine…*), I was looking at that day’s schedule and it caught my eye that there’ll be a session (with several presenters) entitled “The Science of Kissing”, and three hours long, no less:

[…] Click to continue reading this post →

The Hat

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Here’s a strong clue that I’m supposed to be working on writing slides for an important presentation:

Albert Einstein in Aretha Franklin s Inauguration Hat

Yes. I’ve been playing with photoshop. What’s the story? Well, I noticed that there is a facebook page for Aretha Franklin’s wonderful Inauguration hat. You know the one. The page has a huge number of fans already, growing at a rate of something like 200 every ten minutes (when I last looked). People are adding photos of themselves, their pets, and other objects, all wearing the hat. It’s great!

So I, rather than settling down to design those slides I’ve been meaning to get to for the last few hours, thought I’d join in the facebook fun! I could not resist sneaking […] Click to continue reading this post →

Weinberg on BCS

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For some reason I don’t understand, I occasionally get a copy of some random (as far as I can tell) issue the International Journal of Modern Physics A in the post. It just arrives. The people at World Scientific are presumably hoping I’ll get hooked by it and take out a personal subscription or something. Not sure. Well, it has not happened yet (just as it did not with the unsolicited regular arrivals of Angeleno a while back). But you never know.

Anyway, before putting the one that arrived recently on to my shelf (I can’t easily throw things like that away… it’s a problem, I know) I glanced through the contents to see if there were clues as to why this one was sent to me. I found no obvious ones, but the very first article caught my eye. It was a rather good essay by Steven Weinberg (1979 Nobel Prize in Physics) on BCS (J Bardeen, L N Cooper and J R Schrieffer – No, nothing to do with College Football’s BCS.) theory of superconductivity and the importance of the idea of spontaneously broken symmetry in condensed matter physics and then in particle physics (see last year’s Physics Nobel, by the way). I thought I’d point it out to you, since it is rather nicely written and very instructive (whether or not you’re already familiar with the phenomenon/idea).

He begins with some overstatement, however. He expounds upon the difference between particle physicists and condensed matter physicists and although it is amusingly written in parts (I assume intentionally) he really over-eggs the pudding, in my opinion. Look at this: […] Click to continue reading this post →

The Chronophage

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I’m back home in Los Angeles now, after four days in Cambridge (UK) trying to pay attention to several interesting talks and meetings while being eight hours out of sync with my sleep. It has been interesting, but it is good to be back and getting on with the business of starting the new semester. I gave my first class of the season yesterday (upper division electromagnetism), and it looks to be a good group of students. I expect we’ll have fun! Additionally, two research meetings with graduate students meant for a nicely balanced first day back.

It’s (of course) 5:18am, and so while I sit here, wide awake, I’ll tell you about something I saw earlier in the week. chronophage_corpus_clockWhile wandering around for a bit in Cambridge on Monday, I stumbled across the Corpus Clock and the Chronophage. It’d been mentioned to me about half an hour before by a friend, and I made a mental note to ask about it, but did not realize I’d stumble upon it so easily. Did you hear about it last year? I must confess that all the fuss about it totally passed me by. There’s been a lot of silly stuff said about it, including the usual sensational things about time and so forth, but at the core, the whole thing is quite marvellous. I’ve an old-fashioned streak to me, as you know by now, and so that it is essentially a traditional mechanical clock (despite the presence of LEDs to show the time – they are not controlled electronically, but are on all the time and the mechanical works moves slits to make them appear to go on and off) appeals to me immensely. The whole effect of using modern technology to […] Click to continue reading this post →

Galileoscopes and More

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This year is not all about Darwin. There’s even more fun to be had. It is the International Year of Astronomy. It is 400 years since Galileo Galilei looked at the night sky using a telescope, and this is regarded by some as the birth of modern astronomy. There’ll be lots of celebratory events and discussions taking place under this banner, and of course it is a wonderful opportunity to highlight and kindle interest in Astronomy, so keep your eye out for lots of such events. The theme is “The Universe: Yours To Discover”, which I think is rather good, don’t you? See the official website of IYA2009 for more information. Here’s a BBC World service piece about it, in the form of an interview with Astronomer Royal, Sir Martin Rees. (That same page has an audio visit to the Vatican’s Observatory, Castel Gandolfo (a facility previously mentioned on the blog here), which might be of interest.)

I wonder whether you’ve heard of the Galileoscope. It is one of the “cornerstone […] Click to continue reading this post →

Complex

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So where am I and what am I doing? I’m in chilly Cambridge. The one in the UK. It is super cold over here. When we landed in Heathrow at lunchtime yesterday it was below freezing, and the thick cloud of the London sky was right down to the tops of the airport terminals. Everybody seemed to be talking about how cold it was. My wandering in central London for a few hours dragging my suitcase (before heading to Kings Cross and the train to Cambridge) was quite a bit uncomfortable – at least until I realized that a key mission should be to find on Oxford Street a branch of Marks and Spencer’s (now called M&S it seems… interestingly across the street from an H&M, and not so far from where the doomed C&A store used to be…) and buy some long thermal underwear. A bit elderly, perhaps, but very snug and warm against the icy winds and snow flurries, so I don’t care. (Yes, that probably falls under the category of “oversharing”, one of the words of the year 2008….)

icam board of governers meeting

One of the various governance boards I managed to accept to be on last year (despite trying hard to try to say “no” more last year) was that of ICAM, the Institute for Complex Adaptive Matter. For the first time in ICAM’s ten year history, its […] Click to continue reading this post →

Darwin in the Air

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You’ll begin to notice a lot of discussion of Charles Darwin soon. Why? It is his 200th anniversary, and also 150 years since his Origin of Species was published, and so many people and organizations will be celebrating those landmarks. I did a couple of posts last year on Darwin that are worth a look, one about Darwin’s presentation of the evolution idea to the Linnean Society (150th anniversary of that last year) and the other about the wonderful Darwin Online project. See here and here.

Earlier this week I noticed that BBC Radio 4’s excellent series In Our Time (which I’ve mentioned a number of times here and will again) did a four part special documentary on Darwin. I’ve not listened to it yet, but I’ve a feeling it’ll be good. (I’ll be dropping all four parts onto my phone for listening to in those idle moments on some travel I’m about to embark upon.)

Snipping some of the synopses: […] Click to continue reading this post →

Thermodynamics and Gravity

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ads_ballI noticed that Robert Helling shared some thoughts about thermodynamics and gravity today on his blog. He is understandably confused about several aspects of the issue, especially when applied to cosmological issues. (What is the entropy of our universe? Does the Second Law really apply? Does equilibrium thermodynamics even apply here?)

I’ve nothing remarkable to add to the discussion at this time except to note that a blanket statement that thermodynamics and gravity don’t seem to go together (which I don’t think he’s strongly saying) is not one I’d make, since we have a major class of working counterexamples.

The context is the gauge/gravity duals I’ve talked about here a lot, starting with AdS/CFT and beyond. There we know that the gravitational systems are essentially able to display the more garden variety thermodynamics by being immersed in the (regulating-box-like) anti-De Sitter type backgrounds. Then we see that black holes […] Click to continue reading this post →

Red, Yellow, Blue, Green…

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red yellow green blue…among other colours.

View of the day from the garden. (Winter. Number x in a limited series of y.) (Click for larger view.) The rains have gone for a while. The sun is back, with clear blue skies to close out the year.

I’m trying to rest. Well, I’m working on various projects at home, mostly. Colours are on my mind a bit in one of these projects, actually. Later today I’m going to be down in the (only slightly mad-scientist) workshop making a portable screen on which to project films.

Projecting onto the wall is good, but I want to make a silver-grey screen with a dark border that will really pop the colours out. Some of this is about not projecting onto […] Click to continue reading this post →