I’ve been chiseling away at Cycles of Time (2010), by Roger Penrose. I say “chiseling away,” because Penrose’s books are dense and not for the fainthearted. It took me three years to fully absorb his The Emperor’s New Mind (1986). Penrose isn’t afraid to throw tensors or Weyl curvatures at readers.
This is a library book, so I’m a little time constrained. I won’t get into Penrose’s main thesis, something he calls conformal cyclic cosmology (CCC). As the name suggests, it’s a theory about a repeating universe.
What caught my attention was his exploration of entropy and the perception our universe must have started with extremely low entropy.
I’m reading Our Mathematical Universe (2014), by Max Tegmark, and I’ll post about the book when I finish. However he got my attention early with the topic of eternal inflation. That got me thinking about how there are some key unanswered questions regarding the Big Bang and inflation of the non-eternal sort.
Inflation certainly does need some explaining. It may be related to dark energy, as both seem to do the same sort of thing (push space apart). The putative physics of inflation is bad enough; eternal inflation is (in my view) fairy tale physics.
For one thing, eternal? Seriously? Infinite something from nothing?