Just as our brains have limits grappling with numbers, our senses have limits grasping sizes much beyond our personal, human-sized, scale, where different laws of nature dominate. Flies can walk on walls because gravity at fly scale is a barely perceptible pull, and electrical forces are everything. At the subatomic scales of quantum physics, rules change completely. Particles can be here and there simultaneously; until measured, distance, time, energy, and velocity all exist in a fuzzy state of uncertainty. [...]
Gravity on grand scales gets so bizarre it can trip up the best thinkers. When, almost 100 years ago, Einstein’s own equations of general relativity predicted that a massive enough star could implode into a black hole—leaving nothing behind but an extreme warping of spacetime—he didn’t believe it. You could say he saw black holes coming. But seeing is believing, and Einstein didn’t believe. Which is to say: Predicting the qualitative effects of quantitative changes takes more than mere genius. It takes a willingness to accept the unacceptable—something Einstein did on a regular basis. But this extrapolation went too far even for him. [...]
Physicists certainly needed stories to convey the dangers of nuclear bombs. It was hard to make people see (even today) that they are not simply bigger bombs. They were something qualitatively different—a factor of 1,000 different. Frank Oppenheimer, Rukeyser’s schoolmate and lifelong pal, used the example of scaling up a dinner party in your home. What if you invited four people, and 4,000 appear instead? And you have to make do with the same kitchen, same pots, same glassware? This is a fair comparison, he said, because after all, the Earth itself—the people, the homes, the civilizations—does not change even as firepower increases. The introduction of nuclear weapons brought about a phase change so profound it provoked Einstein to remark: “I do not know with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.”
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