Time while on holiday

[andrew s]

Just had a short holiday in France and took " The Singular Universe and the Reality of Time: A Proposal in Natural Philosophy" by Roberto Mangabeira Unger and Lee Smolin for company. For those of you who don't like, a start to, or infinities, in the Universe as proposed by the standard cosmological model this is the book for you. Or it would be if the first half by RMU, a philosopher, was not so repetitive and turgid. It is not a popular science book (their assessment) but a work in old fashioned natural philosophy.

They take the idea that time is real and that the expansion of the universe provides a special reference frame that can define a universal time scale. I.e. one based on special observers at rest with the cosmic expansion (where the Hubble flow or CMB are isotropic). LS, a cosmologist, discusses this and shows that this idea is compatible with SR and GR quoting published work.

They conclude there is just one universe and that it always existed and goes through cycles (or phases). They get in a bit of a fix with trying to argue that this does not mean it does not extend into the infinite past. They also argue that the laws of Physics change with time as a consequence but this seems to me to be a purely philosophical point.

Regards Andrew