The Demon-Haunted World: Science as a Candle in the Dark

by Carl Sagan

So how is shamanistic or theological or New Age doctrine different from quantum mechanics? The answer is that even if we cannot understand it, we can verify that quantum mechanics works. We can compare the quantitative predictions of quantum theory with the measured wavelengths of spectral lines of the chemical elements, the behavior of semiconductors and liquid helium, microprocessors, which kinds of molecules form from their constituent atoms, the existence and properties of white dwarf stars, what happens in masers and lasers, and which materials are susceptible to which kinds of magnetism. We don’t have to understand the theory to see what it predicts. We don’t have to be accomplished physicists to read what the experiments reveal. In every one of these instances—as in many others—the predictions of quantum mechanics are strikingly, and to high accuracy, confirmed.