The End of Cosmology

Here in Queen Mary, we hold a discussion group every Wednesday during term time. The paper we are discussing this afternoon is a recent essay by Lawrence Krauss and Robert Scherrer, which has been causing a bit of a stir in cosmology circles, both in the blogosphere and the real world. The essay won 5th prize in the annual Gravity Research Foundation Essay Competition which always features some interesting reading material.

The conclusion the authors reach is that our knowledge of cosmology and the expansion of the universe would simply be unobtainable in the far future. The acceleration of the expansion of the universe will leave nothing but our own small group of galaxies inside the observable horizon. Evidence of large redshifts at long distances will simply not exist. They reason that pseudo-cosmologists of the future will have to conclude that the universe exists in a steady state, with no reason to expect a big bang initial event.

The New York Times' Dennis Overbye described the essay as “one of the more depressing scientific papers I have ever read”. While I don’t think I would go that far, there are some worrying aspects. As mentioned in the NY Times article, science in the far future will be hamstrung without enough observational evidence, and will end up trying to explain meaningless coincidences.

[T]hey will puzzle about why the visible universe seems to consist of six galaxies, Dr. Krauss said. “What is the significance of six? Hundreds of papers will be written on that,” he said.

The most troubling aspect of this argument is that it does suggest that we are perhaps even now engaging in the same sort of trivial pondering due to lack of evidence. For example any evidences of multiverses or the like which might once have been observable could now be trapped forever beyond even our future theoretical capabilities.

This isn’t the first time this sort of scenario has been suggested, and in fact dark energy is not even required to fuel the acceleration. George Ellis and Tony Rothman came up with a similar idea back in 1987, in a paper called The epoch of observational cosmology (ADS abstract and link to PDF).