Cosmology Conundrum

March 26, 2013

Some colleagues have suggested that my posting on Planck Day was overly frivolous, given the huge importance of what Planck has achieved. (Nicely written up by Andrew Jaffe.) Other colleagues have suggested that Planck Day was bad press, as it was such a huge public non-event, with a big fuss about mild parameter adjustment. I find both these things true, leaving a weird sense of tension and excitement. I’d better explain myself.

First, lets be clear about the technical achievement. Planck is an absolute triumph of technology, engineering, management, and organisation. An amazing machine that has worked beautifully. It also represents a stunning scientific achievement. The lamda-CDM model, and its beautifully articulated engine of prediction, is a conceptual and analytic triumph. Of course this triumph belongs not just to the Planck team, but represents the accumulated achievement of many scientists all over the world over a number of years.

Lets just look at that power spectrum fit. It is not just a question of the theoretical curve going vaguely up and down, in more or less the same way as the data. The detailed agreement is gob-smacking – multiple peaks, their positions, their sizes, their widths, their second and third order curvature. Any scientist will look at this and think “no way is this a fluke”. Don’t let doubters trot out that coffee-time stuff about being able to fit anything with enough parameters. Firstly, that old chestnut is largely nonsense, and secondly, the fit quality is way beyond that.

Parfait. Everybody love parfait

And yet – outside the world of the CMB, the CDM paradigm has problems, as we were reminded here at ROE the day after Planck Day, in a nice wee coffee talk by Jorge Penarrubia.The best known problems are that CDM predicts far too many dwarf galaxies, and galaxy profiles that are much cuspier than observed,  but there are other claims, such as the existence of a very unlikely polar structure of dwarfs surrounding the Milky Way,  and of suspicious uniformities in galaxy rotation curves. All these problems may still get patched up by astrophysical fixes to do with feedback, IMF games, etc… but we don’t know yet.

Its common to hear people say that Particle Physics and Cosmology are in a similar situation – a model rather than a theory – a perfect fit but with no explanation. Why do all those parameters have those particular values? It seems so arbitrary. And what are dark matter and dark energy anyway? In this view, even the boringly successful fit is tantalising because it tells us there must be a deeper theory in waiting that will explain the perfect fit.

That may describe particle physics, but it doesn’t describe cosmology. Rather, what we have is perfect but fishy. How can the model be so perfect in some places and so poor in others? Have we missed something simple? It may well be that the astrophysical fixes do the trick, and then cosmology does look indeed like particle physics – successful but unsatisfying. Or it could be that some conceptual change is needed, and a revolution is waiting.

I’d give the revolution 2:1 against. But thats good enough odds that your eyes are glued to the table… Mesdames et Messieurs, faites vos jeux.

Rich queries and Particle Physicians

May 18, 2011

Roy W wants me to write about science at the IVOA meeting rather than tourism. Well, what we do is all in the service of science, but its not itself science, and the impact is slow and indirect, so its kinda hard. But there are some really promising things. Having finished Table Access Protocol (TAP), the first apps actually using it are now appearing, so instead of just doing simple-minded RA/Dec/radius conesearches, you can do rich SDSS/UKIDSS style queries. The new version of Topcat speaks TAP. People are going to love this. Also the ObsCore Data Model is done, so likewise when you are searching for data resources, you can do something a bit more structured than “give me a list of conesearch services containing the string XQBLARG”. In general, the Data Model world seems to be zooming ahead now, after taking so many years to get going !

Meanwhile, everybody seems happy with VOEvent 2.0, and like VO Event 1.x I am sure it is going to be used in the real world. But you can tell us all about that Roy.

If there is any problem with this IVOA meeting its that it all seems a bit smooth somehow. We need some kind of playful critical agent provocateur. Roy ! Why aren’t you here ??!!

In other news, I just followed a Twitter link from La Crowther to a transcript of the Parliamentary Liaison Committee’s session quizzing the Prime Minister. Questions 23-27 are about science. Its a bit depressing. Earlier on, Cameron’s answers often seem cogent and knowedgeable, whether you agree with him or not, but on Science he becomes rather vague and broad brush, and of course pleads the fifth hides behind the Haldane Principle as usual. When confronted with the claim that particle physics funding has fallen to half its 2004 value, he says “By complete chance, I met a particle physician last night…” But what is worrying is what he claims the “particle physician” told him :

He said that one of the challenges for highly specialised areas of science is that they have to make their applications and bids relevant. They cannot expect to get money just because what they propose is in an important area, they have to prove the worth of what they are doing. I think that is the case for all science funding.

There doesn’t seem to be any grey here. Prove your worth or you are out Jim.

Stone Lions and the End of Particle Physics

September 22, 2008

On Thursday I attended a meeting of the SLAC User’s Organisation (SLUO). Half the talks were about astrophysics, and even some about light sources, but the tone and the worry was dominated by particle physics and its position in the US. There were talks from suits at DOE, the NSF, and the OMB, all of whom had warm words and encouragement, but also barely coded hints about the scepticism in Washington. “Why does it have to be so all or nothing ?” and “does the US really need to lead this area ?'” and of course “whats the economic impact” ? Its very frustrating because the people in power do believe its gripping stuff – thats not the problem –  and with the LHC switching on the next few years will be very exciting  .. but they don’t see where its going, why it has to cost so much, or why anybody needs a big machine in the US, as opposed to some postdocs analysing data. Strikingly, the afternoon had several talks from particle physicists who were re-training themselves as astrophysicists, who explained how much fun it was. More of them later …

Two days later I was catching a flight from San Francisco to London, for a two week stint of back-to-back meetings in the UK. I am typing this about thirty hours later, still only mid-Atlantic, having been booked at various times on seven different flights (involving five different cities) only three of which I have actually been on … This sort of thing hasn’t happened to me too often I am glad to say, but periodically every traveller hits a nightmare journey like this. At first you get real tense, and your adrenalin rises as you try to calculate the options and optimise .. but eventually you just figure what the heck, when I get there I’ll be there, and you start joking with the flight attendants stuck in the same situation.

Suddenly I remembered a poem I read many many years ago. I can’t remember the title or the author, so if the the poet happens to read this blog one day, please forgive me for stealing your idea uncredited. It was in a magazine called Crabgrass. So here is my clumsy prose rendering …

… one morning the citizens of London wake up to find the streets entirely filled with stone lions. Motion is impossible. Half the workforce get on the phone, try to figure out a way round it, register complaints, send apologies to bosses and instructions to underlings, and so on, but all to no avail. The other half stare for a few minutes, then go back inside, make some coffee, read a book, and have an unexpectedly pleasant day.

You join the dots.

Angels over Stanford

September 5, 2008

I had lunch today at the Quadrus cafe, just across the road from SLAC. This is where the angels eat. Years back, Sand Hill Road was buzzing with busy Venture Capitalists, shovelling their money into computer startups. Apparently they are still there, but now they are for looking for alternative energy technologies. Steve Kahn told me that office rental is six times higher around here than in Palo Alto.  This makes SLAC folks nervous. Will Stanford keep backing them when they could flog the land instead ?

On the way back I picked up Symmetry, the PR magazine for Fermilab and SLAC combined. By PR mag standards, its actually a pretty good read. The editorial took me by surprise – it was labelled “Positive News for Particle Physics”. (I wouldn’t have been surprised if I’d kept up with Mark Lancaster’s web page or read this Physics World article )

Back before Christmas, panic and despondency hit US physics at pretty much the same time as the STFC crisis blew up in the UK. Work on the ILC and ITER was cut right back, and almost three hundred redundancies (“layoffs” in US-speak) planned between SLAC and Fermilab. Now it seems Congress has “appropriated” an extra $32M, and the President has announced a supplemental budget. The planned Fermilab layoffs have been halted. Its too late for 125 people laid off by SLAC, but apparently they might want to re-apply …

So how come Parliament can’t vote us some extra money ? Tough guy Willis wrote a stinging report … but he didn’t get us any money. Or did he ? Its pretty hard to tell in the UK system. It could well be that behind the scenes DIUS and the Treasury are doing what they can for STFC, slipping over extra LFCF or TSB money, so they can save money in their main budget etc etc .. but how would we know ? The only rule is that the Minister cannot imply that the Government made a mistake. There simply cannot be any publicly announced rescue. We all know that. But why not ?  Cue the Watcher to tell us its because the Government believes you mustn’t give in to children with tantrums.

Particle Physicists Panic

December 3, 2007

Although astronomers have taken the early public hit with the announced intention to withdraw from Gemini, UK particle physicists have not been slow to notice that STFC’s budget problems could hit them too. They recently had a “town meeting” to discuss the issues, and my PP chums forwarded me an email about this labelled “STFC cuts (PANIC !)”. Since then, I guess the panic has deepened, as the previously public web page with copies of the talks given and notes taken has now become password protected. They are obviously afraid that this is all a sign that pure science is going down in status, like the bad old Thatcher days, and are gearing up to feed Joe Public and Gerry Minister with information about how useful and important fundamental physics (and astrophysics) is. My guess is that this is off beam. There is a slow pressure to prove yourself useful, but I really don’t detect a sudden change, or an intention to run down big science. Its just that STFC got a raw deal and Diamond costs more than expected.

Particle Physicists could be a bit fed up for another reason. It looks like the next big machine – the International Linear Collider – may be a bit slower in coming than hoped, following a US DOE report ranking it rather lower than hope in the queue for US funding. Its bound to happen, but will take a looooooooong time. I learned this when I discovered a new Physics blog, called “Corycia“. Must be one of the most obscure classical references in the blargosfear, but a nice wee blog. Today Owen is calling is teddy bear Jesus.