My research group and I are just back from the summer AAS meeting in St. Louis. Here we all are at the hotel just before leaving:
Our group presented four posters, with primary authors Austin Bourdon, Brent Follin, Ben Rybolt, and me. This means that pretty large fraction of the undergraduate presentations were by UR students. I suspect that we had more undergraduates presenting than any other college, although someone said that Wesleyan had a lot too. If you want to know about the research we were presenting, take a look at Austin’s, Brent’s, Ben’s, and my posters.
The fifth member of the group is Haoxuan Jeff Zheng, who wasn’t presenting this time because he only started research quite recently.
The meeting felt a bit small to me, compared to past AAS meetings I’ve been to: there didn’t seem to be that much going on. There were certainly some good talks, though. John Monnier talked about using interferometers (particularly CHARA) to produce images of rapidly rotating stars. In general, stars just look like points of light, even through the largest telescopes. But with these interferometers, you can actually resolve the stars well enough to see their overall shapes. Rapidly rotating stars bulge out at the equator, so they’re quite far from circular in appearance. Some are rotating so fast that they’re pretty close to breaking up. I had no idea how far the state of the art in this field had advanced in recent years.
The best talk was by Sean Carroll, on one of those questions that sounds stupid when you first hear it, but gets more interesting the more you think about it: Why does time flow in one direction and not the other? Why is the future different from the past? The reason it’s puzzling is that the microscopic laws of physics look the same whether you run time forwards or backwards, which makes it a bit strange that the large-scale universe doesn’t.
A conventional answer to this question is to invoke the second law of thermodynamics. Carroll argued that this only pushes the problem back one step, rather than really solving it. He argued further that none of the usual attempts at further explanation, including the theory of inflation, really solve the problem. He speculated a bit on what a true explanation might look like, but mostly had to admit that we have no idea.