In the bizarre and rule-bound world of quantum physics, every tiny spec of matter has something called “spin” — an intrinsic trait like eye color — that cannot be changed and which dictates, very specifically, what other bits of matter the spec can share quantum space with. When fermions, the most antisocial type of quantum particle, do get together, they pair up in a wondrous dance that enables such things as superconductivity.
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In the Rice experiment, when temperatures drop to within a few billionths of a degree of absolute zero, fermions with equal but opposite spin become attracted to one another and behave, in some respects, like one particle. Like a couple on the dance floor, they don’t technically share space, but they move in unison. In superconductors, these dancing pairs allow electrical current to flow through the material without any resistance at all, a property that engineers have long dreamed of harnessing to eliminate “leakage” in power cables, something that costs billions of dollars per year in the U.S. alone.