Comment by eru

It's hard to make a compelling argument for why a particular problem will never be solved. However, I think it's a reasonable supposition that such unsolvable problems exist. Resurrecting the dead, for instance. In order to faithfully simulate the universe, you'd apparently need complete understanding of the laws of physics. And, you'd probably need a tremendously large (and presumably very power-hungry) computer to run the simulation. There's no particular reason to think that physics will ever be completely understood, and the computer might need more power than all the stars in the universe can supply.

Again, it's extremely difficult to argue compellingly for why something can't be solved: even if it seems to be ruled out by known laws of physics (like traveling faster than light), you can always argue that new laws will be found someday that will be more favorable than the current ones. That argument never terminates, because you don't know what you don't know.