A prediction, or any assertion, that cannot be defended might still be true, but an explanation that cannot be defended is not an explanation. - David Deutsch

If something is permitted by the laws of physics, then the only thing that can prevent it from being technologically possible is not knowing how.

Necessary truth is merely the subject-matter of mathematics, not the reward we get for doing mathematics. The object of mathematics is not, and cannot be, mathematical certainty. It is not even mathematical truth, certain or otherwise. It is, and must be, mathematical explanation.

Quantum computation is … nothing less than a distinctly new way of harnessing nature … It will be the first technology that allows useful tasks to be performed in collaboration between parallel universes, and then sharing the results.