Then there are experiments that are done even though one knows the answer, even though the theoretical prediction is so firm that the theory is beyond serious doubt, because the phenomena themselves are so entrancing and offer so many possibilities of further experiments that one simply has to go ahead and find these things. I would include in this category the discovery of the antiproton and the neutrino and the more recent discovery of the W and Z particles. Also included here are searches for various exotic effects predicted by general relativity, like gravitational radiation.
