Preposterous Universe

 
Gravity essay

Jennie Chen and I have written a short essay for the Gravity Research Foundation Essay Competition. You can find it at gr-qc/0505037; it's basically a distillation of some of the philosophical parts of our longer paper on the arrow of time. Nobody claims to have a really clear picture of the onset of inflation, but two possibilities are invoked most frequently: either "chaotic" initial conditions (a la Linde), or creation of the universe from nothing. We critique the former (following Penrose) on the basis that an appropriate proto-inflationary region is fantastically unlikely to occur randomly, much more unlikely even than the spontaneous appearance of our universe in its current state. And we critique the latter by noting that it violates time symmetry in a completely ad hoc fashion -- why impose certain boundary conditions at early times but not at late times? Our solution to the conundrum is to imagine a nearly-empty de Sitter state that forms the "backbone" of the universe, off of which new inflationary regions are occasionally generated via thermal fluctuations.

The Gravity Research Foundation is a funny institution, originally founded by Roger Babson (who also founded Babson College) in order to promote research into neutralizing the effects of gravity. That's hard to do (impossible, if what we think we know about gravity is anything close to correct), and the Foundation was originally home to quite a few cranky ideas. But more recently it has become more respectable, and nowadays seems to not do much other than sponsor these essay competitions, which feature a lot of very interesting papers by respectable people. My one previous time entering (as a grad student), I got an honorable mention, which is not very hard. This time I'm hoping for some big bucks.

And if you're not overly fond of my philosophizing, try out the Beatles'. "McCartney elaborates Frege's sense/reference distinction." (Via Brian Leiter.)

~ posted by Sean Carroll at 7:56 AM ~ link ~ ~ ~