Our Mathematical Universe: My Quest for the Ultimate Nature of Reality.
I'm irrational to recommend a book I haven't read, but I listened to the author talk for an hour and twenty minutes and he seemed impressive. Not impressive in how advanced his thinking was but impressive in that everything he said was down to earth and he had calm simple explanations.
His book evidently covers a range of topics but The Multiverse was featured on the podcast. The Multiverse is the idea that are many many other universes, perhaps an infinite number.
He explained that a Level 1 Multiverse is one where every possible configuration of matter exists in some universe, but the laws of physics are identical in all the universes. While a Level 2 Multiverse cranks things up a notch. There every possible variation on the laws of physics as we know them exists, along with all the Level 1 variations.
The most amazing fantastical fact mentioned in the podcast was about these magic constants such as the "proton-to-electron mass ratio" which is about 1836. The claim is if some of these numbers were different, even by a small amount, we couldn't exist. The tragic outcomes would range from the sun instantly exploding to the inability of matter to stick together at all. I'd heard this part before.
The kicker this time was that he talked about the "dark energy constant". He said this value needs to be what it is down to 100 digits. That is, if it was changed by even a ridiculously small increment we wouldn't be here.
One conclusion people draw from these ideas is there must be a creator who engineered things so perfectly in order for us to exist. Tegmark offers up his Level 2 Multiverse as an alternate explanation pointing instead to a massive game of trial and error. I'll leave the room now while you all discuss those two theories.
What most impressed me is what he said about the controversy surrounding AI. This is a white hot topic in Silicon Valley today. Will we invent an artificially intelligent entity that enslaves us? I feel opinions on this mirror opinions about consciousness in the sense that everyone seems to be certain about their opinion even while they completely disagree!
Tegmark said simply we don't know. I love that. It's obviously true for one thing and it's also courageous: that's not how one traditionally sells books. We don't know what is going to happen. Let that sink in.
Someone was quoted as saying worrying about an AI takeover is like worrying about overpopulation on Mars. Not that it won't happen, but that it's very premature. Still Tegmark suggests taking some precautions is prudent. He said most of us don't expect our houses to burn down yet we still snuff out the candles before bed.
As for the multiverse somewhere there are infinite number of me's who have already read the book, so maybe I don't even have to.
Links to the podcast and the book.