Astronomy and the War Machine

January 29, 2009

My pal Will Saunders, with whom I spent many happy hours collecting IRAS galaxy redshifts, is one of the guys who wrote “No War” on the Sydney Opera House in huge red letters, and was sent to jail for it. I am proud to know someone with such clear and strong convictions. He is also a vegan. None of this half-baked vegetarian stuff. Makes me feel indecisive. I used to refer to myself as a “part time vegetarian”, and explain to people that although I think the Iraq war is stupid, morally wrong, and frightening, I am not a pacifist. Well, everybody is or should be concerned with such issues as citizens; but they also intersect with our scientific lives. Astronomy is entangled with the war machine more than we like to think.

These issues have been at the back of my mind since Friday. I have been peddling my wares – a seminar combining UKIDSS and AstroGrid – around the State of California. So far I have strutted my stuff at Caltech, SLAC, Berkeley, and Livermore, with Santa Barbara and UCLA booked for the next few weeks. Friday was my gig at the Lawrence Livermore Lab . This was a different experience. It being primarily a weapons lab, and me being a suspicious foreigner (all foreigners are suspicious), I couldn’t take my own laptop on site. I had to email the talk, where it was put on Wim De Vries’ laptop. But I couldn’t even touch Wim’s Mac. I had to do all that “next slide please” malarkey. I just thought it was a bit of a hoot, but some of the scientists who work there grumbled about having to go through these hoops when we weren’t within a thousand yards of anything secret. The pure science side of Livermore has been squeezed in recent years, but in the pub afterwards there was much talk about Steven Chu’s all-hands speech, referring to science at DOE labs as the “jewel in the crown”. Everybody of course has picked up on the new Administration committing to “double federal funding for basic research over ten years”. You can can see that phrase for yourself on this White House web page. Some lab scientists seemed to think that this would revive basic science at big labs, while what they saw as giant make-work projects (like NIF and LIFE) would get sliced back. Hmmm. Time will tell.

But why are there astronomers at all at LLNL ? My starting point is that the Government ain’t stupid. They genuinely believe that funding basic research is not just good for the economy, but also good for defense; and that mingling the researchers is also somehow healthy. They don’t need convincing that basic research is worth money; its only a question of how much. PP and Astro have been squeezed in recent years, but we get hugely more than our predecessors before the Second World War. Our fortunes were transformed by the Bomb, and by Radar. The Government discovered that scientists were smart and useful and could get things done; and the scientists discovered how Government worked, and which strings to tug on in the corridors of power.

Big scientific advances need new technology, and the new technology is horribly often a spin-off from the technology of killing. Where would astronomy be without rockets, and what would have happened without the V2 ? Where would X-ray astronomy be without pointable spacecraft, and who do you think invented three-axis stabilisation ? It was invented at Lincoln Labs and then applied down the road at MIT for SAS-3, not the other way round. Where did those Infrared arrays come from ? I don’t think Rockwell make their living off astronomy.  Ditto Adaptive Optics. We are playing catch-up. OK so we can claim that a Particle Physics lab invented the World Wide Web and gave it to the world; but who paid for the development of the Internet to make that possible ? DARPA of course.

I met Peter Eggleton at LLNL. He bought me a beer to celebrate the 800th anniversary of Cambridge University. Nice chap. For him, a good reason for working at LLNL is access to one of the most stupendously powerful computers on the planet, the TeraCluster 2000. Of course its not just the Big Iron. The code concerned, the bizarrely named Djehuty, contains major chunks of stuff that have been … how shall we put it … repurposed.


Obama and the last scattering surface

January 21, 2009

What a fine day. I saw Obama’s inauguration and attended a colloquium by Rashid Sunyaev.

The three hour East-West time difference was just right. I was able to catch the inauguration speech on TV and still get in to work before coffee. It was a beautifully crafted and well delivered speech. Emotional but not mawkish. Had just enough content to avoid being vacuous, but not so much that his freedom of action is blocked once real world compromises are needed. And very promising from a rationalist point of view .. he said “we will restore science to its rightful place”, mentioned “curiosity” as one of the “values on which our success depends”, and even mentioning “nonbelievers” is very unnusual in America. You can see Andrew Jaffe’s take here, and read the speech here.

Sunyaev’s talk was fascinating. He is of course just a tad well known for things like inventing the “alpha disk” paradigm for accretion disks, and predicting the Sunyaev-Zeldovich effect; but in 1970 he also predicted acoustic oscillations in the CMB power spectrum. I didn’t know this. Its in this paper, published in Russian in 1970, and in translation in 1972.  He said that Zeldovich almost stopped him stating that such observations could measure Omega, because obviously these fluctuations could never be measured ! So now he has a new wacky prediction : seeing beyond the surface of last scattering by looking for the imprint of emission lines produced during the preceding recombination phase. These should produce tiny wiggles in the high frequency end of the CMB spectrum; measuring them could for example tell us the pre-stellar abundance of Helium. Sunyaev said that expert opinion is divided on whether these wiggles can be measured, but the twinkle in his eye let us know the right answer…


People, galaxies, and complexity

January 19, 2009

Which is more complex, a person or a galaxy ? I have been to several seminars recently about various aspects of simulating galaxy formation and structure, on a variety of scales from large scale clustering to nuclear gas flow. Work of this kind is getting gradually more impressive, partly because better physics is going in, partly because algorithms are improving, and partly of course because folks are using bigger computers and gobbling up more CPU hours, thus achieving simulations with more resolution, more particles, or more timesteps. Obviously this must lead to more realism… but you get this strange queasy Borgesian feeling … if we simulate in enough detail to get it right, the galaxy in a box becomes indistinguishable from the real thing. What then have we learned ? Surely understanding involves some kind of encapsulation, some boiling down to a deep but simple statement ? Some kind of emergent law ?

At lunch after one such seminar, I was trying to provoke some of the locals with sceptical thoughts of this kind. Tom Abel had a good answer : the aim of massive simulations should not be to make it look right, but to see patterns and consistencies emerge. The simulations are not explanations, but experiments. Nonetheless Tom and his co-workers make very convincing looking – and stunningly beautiful – pictures. Although we love telling each other how little we know, in fact you could make a good case for the idea that we understand galaxies better than we understand people.

In popular talks I often go beyond this, claiming that people are quantifiably more complex than galaxies. (This is all about flattering the punters of course.) Now, you could go about defining  complexity in a number of ways. Its not about specifying the phase-space position of every molecule, otherwise a bucket of water is more complex than an iPod, and that ain’t right. One useful method is to ask how many instructions it takes to make something. To make a person, you take the information in the DNA molecule. The human genome has about three billion base pairs, and each of those needs 2 bits to specify one of four bases. So in total the information needed is about 750MB, or about one CD. Its instructive to compare that to printed text. A character from the alphabet needs 5 bits, but lets add other stuff and round up to one byte per character The book in front of me has 72 characters per line and 46 lines per page. So DNA is equivalent to 5.2 million lines, about 113 thousand pages, or maybe a couple of hundred moderately fat textbooks. To specify a person you don’t need an entire library, but you do need several shelves of books. By contrast, you can do a pretty good job simulating a galaxy with a few pages of C code. I believe that even the goriest codes are around the 50,000 lines mark. So there you go. A person is a thousand times more complex than a galaxy.

Well, I am sure many of you will be squirming and spotting all the cracks in that argument. It does remind me of the old story about Fred Hoyle, who claimed in a lecture that a star was a “pretty simple thing”. From the back of the room, someone called “You’d look pretty simple from ten parsecs, Fred.” (Special no-prize for anyone who can shed light on this urban myth.)

However, its pretty hard to come up with something objective. As I said, we don’t want to get into the list-every-molecule game. Perhaps this says something important about information. I can never resist the feeling that whenever somebody asks “how much information is there in X ?” the answer is “what do you want to know ?”. For this reason, I suspect that the infamous question of whether a black hole destroys information is an incoherent one. But I had better stop there or I will get stomped on by people cleverer than me. So. There you go. Galaxies simpler than people. From our point of view.


IYA2009 kickoff webcast

January 14, 2009

Today we got an interesting all-roe email which I though I would share with the blogosphere. You have probably noticed that this is the International Year of Astronomy. Tomorrow there is an official Opening Ceremony in Paris. The press release is here. But much more fun, you can follow it on a webcast, available Jan 15th from http://www.astronomy.org/webcast.

There is also a fun new “Cosmic Diary” web site. This includes a blog by Staff Writer Lee Pullen, and you can track the Opening Ceremony action on his blog. (Is there a Twitter, does anybody know ??)


Bertie and the Aliens

January 13, 2009

Back in the summer I bought a little plastic telescope for three dollars at a yardsale. I used it to look at Jupiter from the backyard. Seeing a disc appear was a very satisfying experience. I have a good pair of binoculars, but they are wide angle; good for getting the sparkled splendour of a field of stars, but no good for planets. Now, I am very far from being an expert amateur astronomer, but I do feel that some minimum level of concrete connection with the world outside the Earth is healthy for anyone claiming to understand the physical behaviour of the universe.

Many professional astronomers are dismissive of amateur knowledge and skill. There is a story of two well known senior astronomers gathering on the catwalk of the AAT waiting for twilight to run its course. Joe, an experienced Canadian observer, says “Hey, look at Canopus. That is a real sight.” “Oh”, says Bertie, an old fashioned loud upper class English type, “where’s that ?”. “What ?” says Joe. “You don’t know where Canopus is ?”. “Look,” says Bertie, “I’m an Astronomer not a bloody boy scout”.

As I tell that story, I can’t decide who I’m with. Some days it would definitely be Bertie. Professional astronomy is not train spotting. The point is to understand the physical processes in the Universe, not to collect pretty stars and memorise their co-ordinates. But if you are not careful, professional astronomy can be just a game in your head. That way lies string theory… Every so often its good to be reminded that what we work on is real.

Meteor storms are ideal for this. The cosmos comes to us. The best ever for me was the Leonids, just a few years back. Old seadog Mike Hawkins was holding a party out in the East Lothian countryside, and the sky just came alive. Streak after streak, bright, long, and coloured. I got a lift home with Eelco Van Kampen, and we watched them through the car windows, still bright enough to make your jaw stay open even as we got back to the Edinburgh city lights.

I have never seen a fireball come all the way to Earth. But as we live in the Age of YouTube, I can share the experience of others. Here is the video clip of the beast that fell to Earth in Canada just before Christmas, and here is a website with pictures of the whole slew of meteorites that Canadian scientists have collected since. (Thanks to the Bad Astronomer for posting the link.)

So I did one of those YouTube trail things, looking for more movies of fireballs. This had, umm, mixed results shall we say. But it turned up this gem … Just wait for the very last shot. You will love it.


One of those weeks

January 8, 2009

Sometimes when you are weeding the garden, you unearth hidden treasure. So there I was deleting piles of ancient Firefox bookmarks when  I came across a delightful web page from ye olde days of UK e-science, from oooo, at least five years ago. It illustrates the grim frustrations of software development, but really it could apply to any hard week at work … I am kinda surprised its still there .. so here it is. Enjoy.

Thanks to the long suffering folk at Daresbury, and thanks to Guy Rixon, who I think sent me this link all those moons ago.


Four and a half plugs

January 6, 2009

Some people ain’t got nothin better ta do than read blogs. Christmas Day, I got 56 hits. How sad is that ? Oh. Hang on. I checked, didn’t I ? Damn.  So for the addicts, and while I think up something profound, here are some bloggy plugs.

Plug One. First, that Regator thing. When I wrote about it here I worried I was being suckered in to the vanity press; but I have decided I like it and have added a Regator badge to my widgets. It is true that there are sixty million blogs out there, so a web site that picks and organises a couple of thousand good ones is doing something useful. The other reason I like it is that its all done in Atlanta Georgia. It brings to my mind one of my favourite Laurel and Hardy clips. They are in a restaurant. Phone on wall rings, Stan answers. Listens. Says “Uh Huh. It sure is.”. Puts phone down. Stan sits. Long pause. Olly says “What was that all about ?”. Stan says “well, I picked up the phone, and this voice says “its a long distance to Atlanta Georgia.”, so I says it sure is.”

Plug two. Another “best of” web site has given me (and many of the other usual suspects…) a handful of extra hits every day : bizarrely, this is a site called Find Schools Online. There is an associated blog, which basically seems to be a series of “best of” selections. On Dec 29th they had the Top 100 Space and Astronomy Blogs. Slightly less fussy than Regator, which has 14 Astronomy Blogs. Dec 15th has the Top 100 Web Tools For Learning a New Language. Coo.

Plug Three : Zotero. This is very, very, good. In recent weeks I have been playing with different ways of searching, saving, and organising research papers. ADS and astro-ph are crucial of course; for bookmarking and organising, Connotea and Cite-U-like are pretty good, but Zotero is better; I also played with various client programs like Jabref, but Zotero is much better. Now you can also explore citation links with Paperscope, and grab and plot the data from papers using VODesktop plus Vizier plus Topcat. Some of you will be frowning in puzzlement, but fear not, I am planning a whole post on this stuff, as its great.

Plug Four : Fora TV. Its another aggregator, but for video content of a very high quality. Partners include the Aspen Institute, CSPAN, The Times, New Republic, New York Public Library, and lots more. Basically it consists of a large collection of filmed public lectures. Its full of good stuff. Its like the LRB on TV. Very dangerous . I am hooked.

Plug Four and a Half : I found Fora TV via The Daily Galaxy. It has too much to keep up with, but drop in every so often ..

Here endeth the plugs.


The book next door

January 4, 2009

Today I went out for a haircut and came back with a book. I got the haircut ok, but walking back I stumbled across Bells Books, one of those lovely musty second hand bookstores. I emerged with A Sourcebook in Astronomy 1900-1950, in which Harlow Shapley collected original articles by all the right people – Ed Hubble, Annie Cannon, Tommy Gold, Albert Einstein, Abbe Lemaitre and many others, as well as many others you won’t have heard of. I guess I was in the mood for the history of astronomy. My teacher and good colleague Mary Bruck died in December, and I just finished her excellent book on Mary Agnes Clerke.

Carrying my lucky find, I remembered a discussion I had in the Kings Buildings branch of Blackwells last year. The shop had big piles of Course Textbooks but very little else. The guy on the till explained how Amazon was killing real bookshops – why walk to the store, not knowing if they will have the book you want, when you know you can order it from your living room ? We’re not talking about the latest Dan Brown. We are talking about unnusual books, just the right book. The giant warehouse wins when you are hunting in the long tail. But we miss those magical hours  wandering the bookshelves, browsing. Wandering the shelves is more than just entertaining; it maximises serendipity. As the man in Blackwells said to me, three times out of four, the book we buy is the one next door to the one we came in to look for.

Scientific progress can be like this too. You are hunting for one thing and find another. There are several famous examples in modern astronomy. One is the building of the Jodrell Bank telescope to look for meteor showers, only to find persistent radio sources, which would turn to be the most powerful objects in the Universe. Another is Giacconi’s rocket shot of 1962, funded to look for solar X-rays reflected from the moon; instead it found Sco X-1 and the X-ray background. I have heard some X-ray astronomy old timers say that Giacconi always wanted to find something new and unexpected; the lunar fluorescence thing was just a funding excuse. It took another twenty eight years before X-ray astronomers really did detect the Moon. X-ray image of the Moon (ROSAT, June 1990)

Here is the picture, taken by ROSAT in June 1990. This is such a cool picture. Not only can you see the sunlit side of the Moon, but the other half is dark, because it blocks the cosmic background.  You can just see that the sky shines in X-rays coming from behind the Moon.

Sometimes the Snark is a Boojum after all. Decades of struggling to measure the expected deceleration of the universe, which would tell us its mean density, and finally the supernovae show us something entirely new – dark energy – and the universe becomes a more mysterious place.

I wonder what unexpected corner we will turn down next ?