Those sneaky hobbitses

We had our Friday Lunchtime talks today (it's Tuesday, something to do with dinosaur hunters, branes and Dome C....)

Crighton (Durham) talked about "The latest estimate of the primordial deuterium abundance" and essentially said a) D/H is reasonably hard to do b) we're probably underestimating the systematics when using QSO absorbtion sight-lines to do this sorta stuff c) in general, we're probably underestimating systematics when it comes ot (light) element abundances. Thus BBNS measurements (including 7Li, ahem) is probably in line with CMB Omega_b estimates, and the Universe is safe for another day.
Meanwhile, I'm left to wonder how much a varying fine-strucutre constant screws all this up.

Stott (Durham) got the juices flowing with a overview of his current research, "Evolution of Red Sequence galaxies in X-ray luminous clusters out to z=0.5". A comparison between the "local", z~0.1 LACRS (Las Campanas Cluster Redshift Survey) and MACS (Massive Cluster Survey) at z~0.5 is the primary driver.
JPS wowed us with pictures of galaxy lenses ("here, here and here") and poised the question, "we see little red things in today's clusters, but why don't we see them in clusters at redshifts of a half???". Some sweet stuff.