I've been thinking about No Man's Sky a lot recently and all the technical challenges they must face. For example, how on earth do you store a players location in a world that is so enormous?

I assume x,y,z isn't feasible. I notice the advertised number of planets (18 quintillion) is exactly double the maximum integer you can store on 64-bits, if that is relevant.

From watching tech videos of him (Sean Murray) describing the architecture, he seems to say everything is generated by formula where the inputs are x and y. Obviously he's simplifying, but how might one accomplish this?