I thought of something else to add to this discussion. Daniel has given us several things that mainstream science once thought were impossible but now knows are.

But what about another view? How many things have people claimed were possible, only to be disproven by science?

* You cannot transmute elements through alchemy.

* You cannot cure people through any number of mystical practices (I know people still stick needles in themselves, but who feels the need to release humours?).

* Running a lot will not make your children faster.

* Any machine you build will have an output of less energy than it takes in.

* You cannot fly by attaching wings to your body and flapping them.

* Measuring the bumps on somebody's head tells you nothing about their personality.
Looking at stars will not help you divine your fate.

* No matter how hard you look, you can't find any universal mercury from which all other substances are made.

* Using the powers of your mind to move stuff? Not as effective as your hands.

The fact is, there are a lot of weird claims out there. Some of them may be true. But assuming that because we've been wrong in the past about some of them, then in the future a personal pet belief will be proved true (e.g. faster-than-light travel) is a poor idea.

Stephen