> Written proofs have definite advantages over mechanical experiments. > OTOH, a lot of people (especially those unfamiliar with a language) are > skeptical of proofs that use words 'n' symbols, but find experiments in > which they can actually manipulate the objects to be completely > convincing.
Consider this experimental proof that 2 + 2 = 4. Put two drops of water in a test tube, put another two drops of water in the test tube. Count how many drops of water are in the test tube. It's as good as the marbles in a bag experiment, isn't it?
-- The world will little note, nor long remember, what we say here.