From Eternity to Here: The Quest for the Ultimate Theory of Time - Sean Carroll Unlike my usual practice since joining GoodReads, I very deliberately did not take notes while reading From Eternity to Here. I wanted to enjoy myself with an interesting topic (cosmology) and not be overly concerned with learning anything - the nonfiction analog of the fictional brain candy I read.

But this is the post-GoodReads era of my life so am compelled to offer some note to the interested reader. Thus:

The problem under discussion here is the "arrow of time" - why, unlike the physical principles of space, do the principles of time appear irreversible? It turns out we simply don't know. We know enough about quantum mechanics and classical gravity to make reasonable guesses but absent a theory of quantum gravity we're pretty much fumbling around in a very dark room.

Carroll has his own favored answer - which has to do with the multiverse, de Sitter spaces, infinite entropy, low-entropy states and baby universes, and preserves the reversibility of time (though not within a particular universe (sorry, "Dr. Who" fans) - but he's honest enough to say it's unverifiable with the present state of knowledge and lays out other promising competitors.

I thought Carroll padded the laying out of the problem (and why it is a problem), and he's another author who has a tendency to make cute, folksy, annoying asides but if you're interested in cosmology this is a book worthy of your unrecoverable time.

(In an aside - Reading this book brought to mind one of the worst books I've ever read - John Horgan's The End of Science Facing the Limits of Knowledge in the Twilight of the Scientific Age Helix Books, where the author argues that we've pretty much come to the end of scientific advance and are only mopping up a few loose ends here and there. This is one of the few books that truly disgusted me. Most of my one-stars are simply books that I didn't like but this one made me feel intellectually assaulted. In the light of what we're discovering in space, consciousness and genetics (among the sciences that I'm interested in), Horgan's short-sightedness appears especially appalling.)