>Schrödinger described how one could, in principle, create a superposition in a large-scale system by making it dependent on a quantum particle that was in a su

>Schrödinger described how one could, in principle, create a superposition in a large-scale system by making it dependent on a quantum particle that was in a superposition. He proposed a scenario with a cat in a locked steel chamber, wherein the cat's life or death depended on the state of a radioactive atom, whether it had decayed and emitted radiation or not. According to Schrödinger, the Copenhagen interpretation implies that the cat remains both alive and dead until the state is observed. Schrödinger did not wish to promote the idea of dead-and-alive cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics. However, since Schrödinger's time, other interpretations of the mathematics of quantum mechanics have been advanced by physicists, some of which regard the "alive and dead" cat superposition as quite real. I was taught that Schrödinger's Cat was conceived of as intentionally absurd, but that physicists loved it because it pointed out how absurd physics was being. As the other comment said, its not just that a photon might have gone through either slit, it provably went through both.