How growth of the scientific enterprise influenced a century of quantum physics
Austrian quantum theorist Erwin Schrödinger first used the term “entanglement,” in 1935, to describe the mind-bending phenomenon in which the actions of two distant particles are bound up with each other. Entanglement was the kind of thing that could keep Schrödinger awake at night; like his friend Albert Einstein, he thought it cast doubt on quantum mechanics as a viable description of the world. How could it be real? And yet, evidence keeps accumulating that entanglement exists. Two years ago MIT Professor David Kaiser and an international team used lasers, single-photon detectors, atomic clocks, and huge telescopes collecting light that had been released by distant quasars 8 billion years ago to further refine tests of quantum entanglement. The researchers thus effectively ruled out a potential objection, that the appearance of entanglement might derive from some correlation between the selection of measurements to perform and the behavior of the particles being...