The heat-death of the universe need not bring an end to the computing age. A strange device known as a time crystal can theoretically continue to work as a computer even after the universe cools.
I looked it up and found this article, which I don’t understand. Does the time crystal itself outlast the heat death, or does the ability to perform computations on the time crystal outlast the heat death?
(ie could a world simulated on a time crystal exist indefinitely without having to worry about entropy?)
So a time crystal is an object where the lowest-energy state is constant, periodic rotation. If you cool water enough, it freezes into a regular crystal. If you cool this enough, it keeps rotating…as long as you keep it under extreme conditions. I don’t think you could simulate a world on a single time crystal - can you simulate a world using a block of ice? You can simulate on silicon but that’s because of things you do to it, not its material properties.
But I don’t think you could perform computations with a time crystal after the end of the universe (maybe even at all?). At the heat death of the universe everything is at the same temperature, and maximum entropy. Performing computations requires that you move information around, and will create extra entropy in the rest of the universe - so it won’t work if everything’s already at the same temperature and there’s nothing to drive the computation.
(Right now we can use a battery, which has extra electrons at one end and fewer electrons at the other end, to power a computer, but after the heat death of the universe the electrons will be evenly spread out everywhere. You can’t even collect them back into a battery, because where are you getting the energy to do the collecting?)
Anyone who knows more about this than I do, feel free to correct me, I’m almost certainly conflating energy and entropy. But that’s the gist of it.
