A Short Review of Rees’ Just Six Numbers

Just Six Numbers

Rees is an atheist professor of astrophysics at Cambridge, whose book Just Six Numbers provides an accessible overview of six fundamental numbers that determine the structure of our universe.


– Very accessible, with no math and only a handful of basic figures

– Well-written. Not quite as interesting as Krauss’ Universe from Nothing, but solid scientific writing from an eminent scientist. As usual, found the historical tidbits to be the most interesting, like the fact that Einstein predicted the existence of black holes but rejected them as a mathematical ‘blemish’

– Rees agrees that many of the fundamental parameters of physics are ‘fine-tuned’: “if any one of them were to be ‘untuned’, there would be no stars and no life” (p. 4) and that this fine-tuning could potentially point to the “providence of a benign Creator” (p. 4), although he doesn’t personally believe that it does. Rees favors the existence of a multiverse, an undetectable (near?) infinite ensemble of parallel universes.

– Agrees that physicists should be careful saying things like “the universe came from nothing”: “Even if shrunk to a ‘point’, [empty space] is latent with particles and forces – still a far richer construct that the philosopher’s ‘nothing’.” (p. 145)


– Occasionally disjointed. Each paragraph was very interesting, but I frequently found myself asking “What are we talking about again?” It’s not that Rees wanders off on tangents as much as he’s simply taking an meandering stroll through modern cosmology

– I read the book mainly because of my interest in fine tuning. While Rees affirms that it is real, it was not the focus of his book. Consequently, he doesn’t answer important questions like: “What do you mean by ‘life’?” or “exactly how fine-tuned are each of these parameters?” (he seems to think it’s quite extreme in some cases, on the order of 1 in 10^120 for instance, but doesn’t always give precise numbers) Not at all his fault, but a bit disappointing for me.

– One of the most abrupt endings I’ve seen in writing since the gospel of Mark. The last sentence is: “Or should we seek other reasons for the providential values of our six numbers?” FULL STOP. He should have added “To be continued in the next episode…” or something


Enjoyable book. Lewis and Barnes’ Fortunate Universe was much better with regard to fine tuning, but it’s nice to hear other perspectives as well.