What is the meaning of it, Watson? said Holmes solemnly as he laid down the paper. "What object is served by this circle of misery and violence and fear? It must tend to some end, or else our universe is ruled by chance, which is unthinkable. But what end? There is the great standing perennial problem to which human reason is as far from an answer as ever.
Nobody believes in magicians any more, nobody believes that anyone can come along and wave a wand and turn you into a frog. But if you read in the paper that by injecting certain glands scientists can alter your vital tissues and you'll develop froglike characteristics, well, everybody would believe that.
[Heisenberg's seminal 1925 paper initiating quantum mechanics marked] one of the great jumps—perhaps the greatest—in the development of twentieth century physics.