That's an interesting idea, but I think what proof-of-work (and -stake) provides is an effective Sybil-proof identity system, which your cosmic slot machine wou

That's an interesting idea, but I think what proof-of-work (and -stake) provides is an effective Sybil-proof identity system, which your cosmic slot machine wouldn't. To use a slightly different analogy, imagine that the pulsar variations determined the outcome of a cosmic roulette wheel. What is to stop miners from "betting" on every possible value on the wheel? If winning a spin gives the right to mint some new coins, then the only reasonable strategies would be to make such a blanket bet, or to never bet at all. Perhaps, though, your system could be coupled with a system that restricts participants to one (public key) identity per IPv4 address. The cosmic roulette wheel would then pick a participant at random who would mine the next block and receive the block rewards. I feel like there must be a flaw with this design, other than the fact it rewards hoarders of IP addresses. Perhaps the biggest problem is building a device which can run anywhere on Earth and measure variations in a pulsar, but there must be other globally-measurable random number generators that machines could cheaply reach consensus on.