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Schrödinger's Cat

Back in physics, Erwin Schrödinger takes issue with the Copenhagen Interpretation. To illustrate his concern, Schrödinger devises a clever thought experiment in 1935: A cat sits in a sealed chamber that contains a flask of hydrocyanic acid, a poison that will kill the cat if the flask is broken. A hammer mechanism is rigged to fall and break the flask if a Geiger counter detects the decay of a single radioactive atom that is within the box. When a radioactive atom decays, it emits a special type of particle. According to the Copenhagen Interpretation, this particle exists as a waveform, thus in all possible states, until it is measured or observed. So, until someone looks into the chamber, the radioactive atom has both decayed and not decayed, and the cat is both dead and alive at the same time. This example, Schrödinger reasonably remarks, is "quite ridiculous."

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