Almost Nothing

February 25, 2011

More astronomical hyperbole. I just remembered a story about Glenn White from days of yore at QMW. Glenn, as many of you will know, was and is Mister Molecular Cloud. He was getting fed up with us extragalactic types stealing the limelight. I think we’d just been in the Daily Mirror with the Most Luminous Object in the  Universe, aka IRAS F10214+4724. So when he came back from Hawaii with some pretty random CO data, he put out a press release saying he’d found a cloud with enough Carbon to make all the pencils on the planet. By golly it worked ! Snaffled up.

We are used to thinking of everything in astronomy as bigger and bolder than our humdrum earthly existence. Recently I heard someone talking with passion about the enormous amount of obscuring material towards some object, with an extinction of hundreds of magnitudes… But hang on there. At a normal gas-to-dust ratio, thats a hydrogen column of maybe 10^24 atoms per cm^2. But thats peanuts; the column through the Earth’s atmosphere is much more. If it wasn’t, we’d be able to do X-ray astronomy without those expensive rockets. That obscuring muck is pretty pathetic.

I was expressing these thoughts to Eric Tittley at lunchtime. Indeed, quoth he, there is more stuff in the 10km above our heads than there is all the rest of the way to the edge of the universe. That just made me go quiet for a bit. What a thought.

One of the most striking things about the universe is that it is transparent. And how nice that is; otherwise we couldn’t study those lovely high redshift galaxies. Every X-ray astronomer knows that you have to include the Galactic Column in your spectral fit – but do you add the Intergalactic Column ? Nope.

Ahh, the learned among you cry, this is because the IGM is ionised. However, the WMAP polarisation measurements of the microwave background tell us that the average electron scattering optical depth from here to the re-ionisation epoch is around tau=0.1. So we know how many free electrons, and so how many protons, there are in a typical line of sight from here to redshift ten-ish. If you drill a tube about a thumbnail across from here to eternity, you get about 3 grams of stuff. About as much as a teaspoon of water.

Almost nothing.


Feverish imaginings

February 23, 2011

Last week I gave a popular talk about Active Galaxies, part of the ROE Winter Talks series. Good turn out, some sharp questions, and if there were any nutters they were keeping quiet. Pleasant evening. If you want to see the slides, they are available at the jolly ole personal web page. You won’t get the full effect though, as I like interspersing the pretty pix with impersonations of the Doppler Effect, and demonstrations of Gravity Power by dropping things on me foot etc etc. Rule number one : do everything in threes. Rule number two : wake ‘em up every so often. I think of this as a variant on Brechtian alienation. Rule number three : never patronise. Simple is good, colourful analogies bad. This is why P.B.Cox is so good I think. He’s very concrete, and tells the truth.

Every so often of course you show some gaudy picture of a black hole swallowing stuff or such like. Its good at this point to pause and look ‘em in the eye and say “… you do know this is an artist’s impression, right ? Wish we had data that good … Anyway…”. Today on the interwebs I came across a wonderful example of runaway impressionisation, if thats the word I want, in a Gemini press release. This reports what looks like a rather nice piece of work by Sylvain Veilleux and others; a GMOS IFU observation of a high velocity conical wind flowing out of nearby Active Galaxy MKN 231. (I think its the nearest BAL QSO ..)

Exhibit A : the actual data.

Some of the squares look a bit different from the other squares.

Some quite interesting data.

MKN 231 in all its horrific glory

Exhibit B : artistic rendering.

Crikey. I’m standing well back from that, mate.

The beast up close

MKN 231, an artist's crude approximation

Hmm. Thinks. Can I get that Lynette Cook to knock me up a really scary warped disk ? Thats what Martin and I should have had for this paper.


Arabic Science Tidbits

February 10, 2011

Another episode in the “Andy’s favourite books” series. I just finished reading “Pathfinders : The Golden Age of Arabic Science” by Jim Al-Khalili. Jim is a physicist from Surrey, but also a TV presenter – you may remember “Atom” and “The Secret Life of Chaos”. This book grew out of a three part TV series called “Science and Islam”, but goes well beyond it. I love books that are popular in intent, but also serious works of scholarship. I won’t attempt to review the whole book. Here are just a few things that struck me as interesting.

  • I had thought that mediaeval Arabic science was important mainly for passing the flame from Greece to Europe, and that this happened through Andalusia. In fact they clearly made deeply original contributions and greatly improved on Greek science; and the Andalusian thing was a late stage. The golden age was ninth century Bagdhad.
  • As ever, patronage was crucial. The early Abbasid caliphs encouraged and funded open-ended work, which was incredibly successful. This coincided with growth and confidence of the Abbasid empire itself. As the good times ebbed, science continued, but the authorities were more insistent on it being useful – economically, militarily, or religiously. Sound familiar ? Thinking of the Medicis of course…
  • The broader intellectual outlook was important for encouraging science. Just as Renaissance science flourished in the context of the humanist movement, so too did Arabic science in the context of Mutazilism , which argued against over-literal reading of the Qu’ran,  and stressed the importance of human reason within Islam.
  • Why then ? Why there ? Al-Khalili suggests there is a technological answer –  papermaking (as opposed to papyrus or parchment) which came to Samarkand in 751 when a Chinese army was defeated, and prisoners taken who knew the technology. Flax and hemp were abundant around Samarkand. Around the same time, there were great advances in the making of dyes, glues, leather, and book-binding techniques, all of which resulted in cheap and robust books.
  • Hundreds of years later, Al-Khalili argues that part of the reason for the decline of Arabic science just while European science was starting up, was that Arabic script was much harder to print than Latin script, because letters take different shapes depending on their position in a word.
  • Here is a favourite wee snippet, which is the origin of the term “sine”, as in opposite-over-hypotenuse. Hindu mathematicians used the Sanskrit word jya-ardha, meaning “half the bowstring”. (Draw the chord of a circle and stare at it…) This was abbreviated to jiva, which Arabic scientists transliterated as jiba, and customarily abbreviated as jb. Robert of Chester first translated the Arabic work, and misread jb as jayb, which means “pocket”. So he used the Latin word for pocket – sinus.

Well you do learn stuff if ya read books.


Astronomy Grant History

February 4, 2011

Time for me to break a rule.

As many of you will know, I am currently chairperson of STFC’s Astronomy Grants Panel. I have steered clear of discussing AGP business on this blog, for obvious reasons. However, the current round is now complete, so I can relax that rule somewhat. I wrote a chairman’s report which went out yesterday on the astrocommunity email list. Paul Crowther has put it on his website, so you can read it if you haven’t already. Telescoping Peter has also done a quicky. I am not keen on getting into nitty-gritty implementation stuff in this arena, but some interesting big picture things have become clearer, which are quite appropriate for the blog. So here we go…

What really has happened to Astronomy grants funding over the last fifteen years ? If you ask any random astronomer over coffee, they will know for sure that grant funding has been cut inexorably for years. On the other hand, if you ask a random condensed matter physicist over coffee, they will know with equal clarity that astronomy funding has been ballooning out of control, forcing ISIS to close half the year etc. Meanwhile we suspect that the average Whitehall Mandarin believes that the essential problem is the growth of the astronomical academic community. Universities know that astronomy courses get bums on seats, so more and more astronomers get appointed, producing a pressure on facilities and postdoc numbers.

So what is the truth ? With help from STFC grants staff and E&T staff, and as ever, the redoubtable Crowther, here are the figures. The size of the academic community is estimated mostly by returns to the PPARC / STFC Education and Training Committee, for the purposes of calculating PhD quota places. It includes permanent academic staff, temporary lecturers, and senior fellows, such as RSURFs and PPARC/STFC Advanced Fellows – what one might think of as the “PI community”. The size of grant funding is characterised by the number of RA awards made in each year. Of course grants also fund technicians and equipment, and recently, part of investigator staff salaries, so the real situation is more complex, but the number of RA awards is a reasonable metric, and it is a number that people are directly interested in. Note that on average the number of RAs in place is roughly three times as large.

Astro grant and community data

Evolution of the astronomical community and grant funding

So what do we see  ?

  • The academic community has indeed grown, but by less than a factor of two, and the growth seems to have flattened off
  • From 2000 to 2006, PPARC, and briefly STFC, responded to this pressure : grant funding improved. But don’t forget this is during the good old Brown days when the Science budget doubled
  • Since 2006, grant funding has plummeted. It is now 50% of the 2006 peak
  • Its not just that we have fallen compared to the historic maximum. Grant funding is now at two thirds of the 2000 baseline.
  • At any one time, about one academic in three is in possession of an RA

Wearing my chairman’s hat, I can tell you that I showed this plot to PPAN, and an earlier version to Keef and Wadey in private conversation. Note that none of this tells the sceptical politician what the correct level of astronomical grant funding should be. But I hope at least it adds a bit of clarity to an often confused discussion.


EPSRC : a capital affair

February 2, 2011

I just came back from an EPSRC roadshow presentation to our University. Interesting to compare this to the STFC one we got a week or so back. Possibly the most striking thing, given that EPSRC is the biggest research council (budget 760M), is that the attendance was smaller than for the STFC show, and there was a much larger fraction of finance and admin people as opposed to scientists. I think this shows that despite all the troubles of the last few years, astronomers and particle physicists still think of STFC as “their” research council, whereas other physicists, chemists, engineers etc think of EPSRC as a remote government body that holds some money they can ask for.

Of course EPSRC are full of impressive sounding noises about “strategic choices” and “nurturing leadership” and “concentrating excellence” and so on, but the truth is they have very few levers, and no coherent community to converse with, so I doubt if the fuzzwords will have much impact. Talking of which, they also talk of “embedding impact” and “driving cultural change”, but in fact what they (and the rest of RCUK) are doing is slowly broadening and loosening the meaning of “impact” so we can all do some. Fine by me.

So whats the big budget picture ? EPSRC are facing a 3% cut in cash year on year, so when deflated, thats looking a bit grim. Of course, as the EPSRC chappie told us, these are the best of times; in cash terms, they are at a maximum, and even when deflated, 2010 is as good as 2004. But we are looking at the downward slope. For many people its worse than that. About half the EPSRC budget is in those societal themes – energy, digital economy, health etc – and they are being protected. Normal disciplinary grants – now cutely called “National Capability” are now at 458M, next year 427M, and 400M the year after that.

Scarier still, for some, is that capital cuts are severe – down by a factor two from about 100M to about 50M. Problem is, about half that 50M is tied up in Culham fusion stuff. So getting big equipment from EPSRC is going to really tough. In fact, they are talking about moving some money back into equioment – by taking it from grants of course.

Meanwhile, they are trying to apply pressure for people to do equipment sharing, as per the Wakeham Efficiency Review. This made my condensed matter and chemistry chums a bit cross. According to them, they are pretty good at this, whereas the medics waste lots of money this way – every group has to have its own equipment, and their labs (according to my colleagues..) are full of things that are used one or two days a year. Anybody know if thats true ?


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