Archive for February, 2010

When Energy Becomes Form

Posted in Art, The Universe and Stuff with tags , , , , , , on February 28, 2010 by telescoper

I’m back in Cardiff, exhausted but, at the same time, rather exhilirated by the past few days in Geneva. Before I crash out I thought I’d update the post I filed a couple of days ago.

On Friday we visited CERN, the highlight of which visit was, for me, seeing the facility where they test the superconducting magnets used in the Large Hadron Collider. We also saw the surface buildings of the ATLAS experiment, but since the LHC was getting ready to rumble again after its winter break we weren’t allowed to see the thing itself, 100 metres below ground. Coincidentally, I learned today that the LHC is now back making collisions once more. Obviously, the practical tips I passed on while I was there did the trick. One likes to help where one can.

The rest of Friday, back in downtown Geneva, was bizarre to say the least. We had the obligatory Swiss dinner of fondue, which is basically a big bowl of melted cheese into which you dip bits of bread repeatedly while hoping that at some point they’re going to bring some proper food. They don’t. To make matters worse we were serenaded by Swiss folk music:  cowbells, alphorns, yodelling – the works. One of the musicians was the spitting image of Dr Evil from the Austin Powers movies but at least there was no sign of Mini-me. I was traumatised by the thought that the world might be brought to a premature end, not by the LHC creating black holes but by excessive yodelling.

After that, as midnight approached, all 24 of us – 8 scientists, 8 artists and 8 architects – gave very short presentations about our work to the others in the hotel lobby area.  I couldn’t do justice to the range of ideas and forms presented there in a short blog like this so I’ll just say it was totally fascinating to listen to these people, see examples of their work, and have the chance to ask questions.

Saturday was the most intense and also the most interesting day. We were housed in a beautiful 19th Century house in the old part of Geneva that used to be the French ambassador’s residence the whole day. Split into various groups we thought, discussed, sketched, scribbled and generally brainstormed our way towards ideas for something to exhibit on our allocated theme. We got together at the end so each group could exchange their ideas with the others. It seemed every group had great fun and there seemed to be some great concepts floating around.

The artist I’m collaborating with is Carlos Garaicoa, who was born in Cuba and who has exhibited his work all over the world. He now shares his time between Havana and Madrid. He showed us examples of his work encompassing a huge range of materials and technologies: video, photography, sculpture – you name it. One of the themes he has been interested in is the idea of documentary matter, meaning objects of various kinds that bear testimony to events or forces acting on them.  Eyal Weizman is the architect Carlos and I will be working with.  He’s a research architect who has, amongst other things, recently completed a long project looking at the construction of the wall that the Israeli government has built in the west bank

And then there was me, like a fish out of water. I had looked at the title of the programme, Beyond Entropy: How Energy Becomes Form and decided that it might be interesting to get across the central idea in general relativity, i.e. that gravitational forces can be described in terms of the curvature of space. In my presentation I took this to an extreme and tried to explain how the large-scale structure of the Universe is shaped by small ripples in space in the early Universe that evolve under the action of gravity to produce the structures we see on scales as large as 100 million light years. It seemed to be a good example of gravitational energy becoming form. I summed it up with a quote from John Archibald Wheeler:

Matter tells space how to curve. Space tells matter how to move

Taking cue from these perspectives we had a wide-ranging conversation that took the idea of gravity as an effect of space, and explored this in more general contexts and from different angles. Space is often understood through its boundaries or through the surfaces constraining it and these edges take on a form that represents a sort of diagram of the forces that have acted on it. On a human scale we thought about walls and how the path they follow is shaped not only by topographical constraints but also by socioeconomic considerations. Walls and buildings generally suffer decay or damage too, including catastrophics events like explosions or earthquakes.

We also talked about the relationship between surfaces and the spaces they enclose or divide. The path of a wall such as the west bank barrier is extremely complicated because of the interplay between such factors. It curves in and out seemingly at random, but its shape makes it a document that contains information about the forces that have shaped it. It is a document in itself, not just because it happens to have things written on it in some places!

This thread of discussion got us interested in the possibility of using material objects to reconstruct the history of the processes that formed them: the Moon’s surface offers an example wherein the sequence of impacts can be inferred from the pattern of overlying and underlying craters. This led on to discussions about the relationship between surfaces and volumes generally, taking in holography as a specific example where  two-dimensional object contains three-dimensional volumes.

This all took us quite a long way from the initial riff, but I’m glad of that. My main worry about getting involved in this was that we might end up producing something that was merely didactic, just a fancy metaphorical treatment of basic physics. I wanted to avoid that because I think it would be very boring. I think I shouldn’t have worried that we might head in such a dull direction.

Some of the other groups managed to work up concrete ideas for prototypes to be exhibited. We didn’t really get that far. We were much keener to explore as many concepts as possible before settling on one. For myself, I was just really enjoying the discussion! There are no real constraints on what we can make – within reason of course. Sculptures, plans, buildings, installations, videos, photographs, and even books are all possibilities. It’s quite scary having such a blank canvas. We discussed a number of ways we might develop our discussion into material that can be exhibited but they all need a lot of work to develop, so we’ll carry on our collaboration remotely. I’m quite keen to bring some sort of holographic element into it, and promised to investigate the possibility of making some prototypes.

For the meantime, however,  it’s back to reality for me. A lecture to prepare and give, problem sets to get ready and an exercise class to run, an examination paper to finish writing, and a whole afternoon at the School’s research committee. I wonder if what I’ve been doing over the weekend will count as having “impact”?

The True Origin of CERN

Posted in Uncategorized with tags , , on February 27, 2010 by telescoper

During my fascinating visit to CERN to see the Large Hadron Collider yesterday it occurred to me that many of my readers might be unaware of the true historical origin of that organization. I have to say the general misunderstanding of the background to CERN is not helped by the information produced locally which insists that CERN is an acronym for Conseil Européen pour la Recherche Nucléaire and that it came into being in the 1950s. This is false.

CERN is in fact named after the Dorset village of Cerne Abbas, most famous for a prehistoric hill figure called the Cerne Abbas Giant. The following aerial photograph of this outstanding local landmark proves that the ancient Brits had the idea of erecting a large hardon facility thousands of years ago…

Beyond Entropy

Posted in Art, The Universe and Stuff with tags , , , , , on February 26, 2010 by telescoper

It’s a cold and rainy morning here in Geneva, but I’m really looking forward to the next few days here. I arrived yesterday evening after a flight that was longer than it should have been. It seems the French air traffic controllers went on some sort of strike so my flight from Heathrow wasn’t allowed to cross French air space. For a flight between London and Geneva that is a bit of a problem. In the end we flew west over Belgium and then down into Switzerland from the North, the whole thing taking about an hour longer than expected. Still, when I did get to where I was going I found the hotel nice and comfortable and, better still, had a very enjoyable dinner at a swish Italian restaurant. It was nice to leave the chaos of French airspace behind.

I’m here as part of an unusual research project called (ironically, in the light of the aforementioned travel problems) Beyond Entropy. Organized by the Architectural Association School of Architecture, this experiment will bring together a group of artists, architects and scientists to investigate the notion of Energy. The way this is being done is by setting up a series of groups (one artist, one architect and one scientist) to look at each of a number of different forms of energy: potential, electric, thermal, mechanical, and so on; my own focus is gravitational energy. Each group will work together over the following few days to generate ideas a collaboration intended to create a work of some sort that gives form to the specific concept of energy they’re looking at. The subtitle of the project is “When Energy becomes Form”.

After we go back home, we’ll continue to work over the following months to produce prototypes of whatever emerges from the collaboration. The results will be exhibited at the Venice Architecture Biennale and the Architectural Association in August 2010. It is hoped that next year these prototypes will be developed into full-scale installations for the Venice Art Biennale in 2011.

I have no idea at this stage how the collaboration will work out or what is going to come out at the other end. The canvas is completely blank. I don’t really know the artist (Carlos Garaicoa) or the architect (Eyal Weizman) that I’ll be working with either. That makes it strangely exciting. At any rate it’s certainly different from the sort of scientific workshop I usually attend.

Anyway, to kick things off we’re going to be spending most of today at CERN, where I’ll be heading by bus just about as soon as I’ve finished this blog post. Later on today I’ll be giving a short presentation about how gravitational energy relates to my own research in the hope that this will stimulate a few ideas for my collaborators. Arts-science collaborations like this have been tried before and they have a chequered history, but we’ll just have to see how it goes. It feels more like research than most research workshops I’ve been to, in fact, because I really haven’t a clue what is going to happen!

P.S. Fellow blogger Andrew Jaffe is here too, but I think I might have beaten him in the competitive blogging stakes.

New Cats on the Block

Posted in Columbo with tags , on February 25, 2010 by telescoper

Having a slightly later than usual breakfast this morning, I noticed two feline intruders in the garden. I’ve never seen either of them before so it was quite a shock.

One of them was a stunningly sleek black cat with spectacular orange-coloured eyes. This one is clearly a very cool animal, sitting elegantly on the shed roof  and surveying the scene below with apparent disdain. The other one was totally different: a tortoiseshell  with white patches, young and quite slightly built, with a small face but big ears and a very large nose. Most comically of all, cat number two had disproportionately large feet to the extent that she (?) looked like she was wearing white boots.  I went out to try to take a picture, but they both did off like greased lightning as soon as I went outside.

Columbo didn’t pay them much attention, so maybe they’re regular visitors and I only noticed them this morning because I’m on a different routine, heading off to the airport instead of going to work. I’m sure if they went anywhere near his food it would be a different story.

Anyway, this little episode reminded me to let Columbo’s many admirers know that he’s doing fine. He’s spending more time outside now that the worst of the winter appears to be over (?) and seems to be in good spirits. I promise to post some pictures when I get back. I know I’ve promised before but I keep forgetting.

The Solution

Posted in Cute Problems with tags , , on February 24, 2010 by telescoper

A few days ago I posted a little puzzle about the resistance measured between two adjacent nodes in an infinite square grid made of of 1Ω resistors. There was a bit of discussion after the post that hinted at the solution but, since a few people have asked me about it, I thought I’d post a fuller answer here.

The quickest way I know to get the answer uses the Principle of Superposition, as illustrated in the following picture.

Consider two copies of the grid, both earthed at infinity. Imagine injecting a current of 1 Amp into the grid through a wire attached to node A as shown in the top left of the picture. The current will run to earth through the grid, but, by symmetry, it is obvious that 1/4 of the current entering the grid through A must travel through each of the 4 wires radiating out from it. Each of the wires leading out from A therefore carries 0.25 Amps in this solution.

Now, in the top right hand picture, forget about A, but attach a wire to B and pull out 1 Amp from the earth (at infinity). By a similar argument to the first diagram, 0.25 Amps must be flowing into B along each of the wires connected to it in the directions shown.

We now have two perfectly good solutions for currents flowing in resistive networks. The principle of superposition says that if we add the two solutions we also get a solution. Adding the two configurations above means that the resistor joining A to B must be carrying 0.5 Amp (0.25 from the first solution and 0.25 from the second, both in the same direction). But this is a 1Ω resistor so the Voltage across AB must be 0.5 V.

Now think of the whole mesh as being a black box in between the input wire and output wire. This black box has a current of 1 Amp flowing through it and the voltage dropped is 0.5 V. It’s resistance is therefore 0.5 Ω.

If anyone has a better solution than this, I’d like to see it!!

Scientists in Residence

Posted in Biographical, The Universe and Stuff with tags , , , on February 23, 2010 by telescoper

I’ve managed to get through the hectic  first couple of days of what promises to be a very hectic week without feeling too much of the strain, which is quite a pleasant surprise given my advancing senility.

This week a whole bunch of Cardiff astronomers are taking part in a Scientists in Residence scheme at Monkton Combe School which nestles in among the lovely hills in the picturesque countryside near Bath. The idea was to try to give the pupils some sort of idea what it’s like being a scientist – specifically an astronomer – by having an intensive series of teaching sessions run by scientists who visit the school for several days running.  A whole range of different types have taken part, from graduate students and postdoctoral researchers all the way down to Professors. Some, in fact, have been staying overnight there too.; it’s a boarding school, in fact.

As with most things these days, I’ve been a bit of a freeloader in this thing – the course materials were prepared by others, principally Chris North, so all I had to do was turn up and lend a hand on the day. Members of the department with duties at Cardiff have only been able to go for part of the time and even that has meant, for me at least, a bit of dashing backwards and forwards on the train. On Monday I had a full complement of meetings, lectures and exercise classes in Cardiff before heading off to Bath to give an evening lecture on The Big Bang to what turned out to be quite a large and attentive audience of sixth-form students. When I finished I had to get the train back to Cardiff – about 70 minute journey – in order to be able to give Columbo his evening insulin fix in good time.

This morning I was up at six to get the train again to Bath – after doing the necessary with Columbo again – in order to take part in a classroom session where we took the students through activities centred around the idea of using the orbital motions of astronomical objects to work out masses. I found this very interesting. On the one hand the students were keen and very easy to interact with, but on the other this experience reinforced the impression that today’s A-level physics students are given a syllabus that is diluted beyond all recognition compared with what older generations of physicists learned. Even in a private school, with excellent laboratoty facilities and highly motivated teachers, it is difficult for todays 16-18 year olds to learn anything meaningful about what physics is really like.

Not having kids of my own, I’ve only observed the changes in educational standards over the last decade indirectly, so this couple of days was a bit of a reality check for me. Unless someone can be persuaded to force schools to teach science properly again, university lecturers will have to carry on doing what is essentially remedial teaching.

Anyway, I’ve found the last couple of days very interesting and I hope the others taking part in the week will enjoy it as much as I did.

You might reasonably ask why a bunch of University academics – mainly funded by the taxpayer – should be running backwards and forwards organizing activities for a posh private school? The mercenary answer is, of course, that some of the kids we’ve been talking to might actually turn into Cardiff undergraduates one day and even if only one does so, the income that generates for the School of Physics & Astronomy more than pays for the number of person-hours we have put in. But even if that doesn’t happen it’s still worth it. Our plan is to offer this type of activity to all kinds of schools in  local areas, not only for our own recruitment, but also for the general purpose of “outreach”, communicating an interest in science in the society beyond academia. This week is the first time we’ve done it. Undoubtedly some things will work and others won’t. This week we will iron out some of the problems before we take it on the road to more challenging audiences.

It will need to be a good show if it is to go down well in the Valley Comprehensives, and what better way to improve it than to practice on the rich kids?

Tiger Rag

Posted in Jazz with tags , , , , on February 22, 2010 by telescoper

Being a bit busy last week I didn’t have time to celebrate Mardi Gras or, as it’s known here in Britain, Shrove Tuesday. I was fresh out of shroves last Tuesday anyway.

Last year at this time I blogged a bit about Mardi Gras parades in New Orleans, the home of Jazz and that came to mind again when I found the following clip on Youtube. It’s from an experimental film made in the 1950s called Cinerama Holiday which involved shooting the film using three cameras and projecting the results onto a curved screen to make the viewer feel in the middle of the action. There was also an early attempt at surround sound. Interesting though this is as a bit of film history, the thing that caught my eye was the little bit of Jazz history it captures.

Jazz began with the  marching bands that performed in New Orleans but then largely moved into the bordellos of Storyville, the biggest (legal) red light district in the history of the United States. When Storyville was closed down in 1917 most professional jazz musicians lost their only source of regular income. However, a few years later, in 1919, the United States Senate proposed the 18th Amendment to the Constitution which prohibited the manufacture, distribution and sale of alcohol for human consumption and ushered in the era of Prohibition. This turned Chicago into a bootlegger’s paradise and jazz musicians flocked there to perform in the numerous speakeasies. That’s why the great New Orleans Jazz records of the 1920s were all made in Chicago and it also caused the music to evolve in new directions.

However, not all Jazz musicians left New Orleans. Many stayed there and kept the music going in authentic style. One of the characters who did so was the legendary Oscar “Papa” Celestin who led various bands through the 20s and 30s, including one called The Original Tuxedo Jazz Orchestra. Everything was an orchestra in those days, come to think of it. These bands kept going through the depression but never really achieved great commercial success until the traditional Jazz revival of the 1950s.

It must have been strange for Papa Celestin to have become a celebrity in his old age – he was born way back in 1884 – but that’s what happened in 1955 when he appeared in this film. I never knew that he’d appeared on the big screen and it’s great to see him in the flesh, even if the Cinerama format doesn’t lend itself to Youtube particularly well. He turns out to have been quite a showman and is clearly having a lot of fun in the “hold that tiger” chorus. I would love to have seen these guys play live. I bet they were a blast!

The tune they’re playing is another New Orleans flag-waver called Tiger Rag. This was first recorded in 1917 by the Original Dixieland Jazz Band and its composition is credited to Nick Larocca and Larry Shields who played with that band. There is a considerable argument about who actually wrote it, and the first section is definitely taken from a dance called the quadrille that was popular in New Orleans around the turn of the century, but it’s too ancient now to matter much anyway.

You can find countless renditions of Tiger Rag on record and on the net, but this is just a bit special. I hope you like it.