Is There a Certainty in Mathematics?

Mathematicians are proud of this absolute certainty, and scientists tend to be a little envious of it. In science, there is no way of being certain of any proposition, however well one's theories explain existing observations. Virtual reality underlies the fact that when observation is the ultimate arbiter, between theories. There can never be any certainty that an existing explanation, however obvious, is even remotely true. But when proof is the arbiter, it is supposed there can be certainty.