Cosmology/Glasgow exam technique

April 15, 2010

Along with a large fraction of the UK astronomical community, I am at the National Astronomy Meeting (NAM2010) in Glasgow. Just imagine a well placed bomb. Could be like the Manchester United Plane Crash all over again.

Two fabulous plenary talks this morning from George Esthathiou and Rosie Wyse. Plack has completed its first survey, but George is not allowed to show us the CMB maps yet. We have to wait until October 2012. (Southwood was in the audience, so he had to behave…) But he did give us a taster – Galactic cold dust map, made by combining Planck and IRAS.  Rosie Wyse showed us all sorts of fascinating stellar population data reflecting the merger history of the Milky Way and other nearby galaxies, as expected in the standard CDM cosmology. But she also showed two worrying things. The thick disc is thought to be made by mergers stirring up an older thin disc. But the stars in the thick disc are really old, suggesting the thick disc of the Milky Way has not been affected by mergers since about redshift two. The second niggle was that the distribution of abundances is consistent with the stellar initial mass function being constant through cosmic history – whereas the galaxy formation simulators desperately want early star formation to be high-mass biased. Hmmm.

Brain spinning, I wandered across the corridor to the Hunterian Museum. This has one of my favourite pieces of Glasgow History – the Blackstone Chair. From mediaeval times until the 19th century, this is how Glasgow students were examined. When you were ready, you sat on a special chair surrounded by Profs. They fired questions at you for twenty minutes, with the sand running out just behind your head. Then some flunky stamped a pole on the ground and you were done.

We gotta bring this back.