The Making of the Atomic Bomb: 25th Anniversary Edition

by Richard Rhodes

Bohr had found a solution to the spiraling flights of doubt by stepping out of what Kierkegaard called “the fairyland of the imagination” and back into the real world.289 In the real world material objects endure; their atoms cannot, then, ordinarily be unstable. In the real world cause and effect sometimes seem to limit our freedom, but at other times we know we choose. In the real world it is meaningless to doubt existence; the doubt itself demonstrates the existence of the doubter. Much of the difficulty was language, that slippery medium in which Bohr saw us inextricably suspended. “It is wrong,” he told his colleagues repeatedly, “to think that the task of physics is to find out how nature is”—which is the territory classical physics had claimed for itself. “Physics concerns what we can say about nature.”290