[chr1]

The fact that nothing can propagate faster than light speed, allows to isolate segments of universe from one another. Of course you can not simulate the whole universe exactly, but simulating a part of it, like completely closed room, or a different smaller universe, is still interesting and useful.

Wolfram proposes an interesting solution to the question of free will, that does not require any randomness: computational irreducibility. It is the hypothesis that for some computations there is only one way to perform. That is if you try to predict what an AI will chose, your only option is to create an exact copy and let that copy to make the choice.