The last bit you mention reminded me a lot of The Physics of Immortality (Frank J. Tipler, 1994) which I first read in when I was thirteen or fourteen years old. This was before it had been proven that the cosmological constant existed and was positive, so he was musing about how a quantum computer instantiated in the final moments of a Big Crunch would have asymptotically infinite processing power and could simulate everybody who ever lived (and everybody who didn’t actually live, but could have, too).
