Schrödinger's cat in popular culture whales a call that they could locate each other by. Schrödinger's cat in popular culture Schrödinger's cat is a thought experiment, usually described as a paradox, devised by Austrian physicist Erwin Schrödinger in 1935. It illustrates what he saw as the problem of the Copenhagen interpretation of quantum mechanics applied to everyday objects. The thought experiment presents a cat that might be alive or dead, depending on an earlier random event. In the course of developing this experiment, he coined the term "Verschränkung" (entanglement). It was not long before science-fiction writers picked up this evocative concept, often using it in
Measurement in quantum mechanics bit more convenient to write the Hilbert space as a direct sum of multiple eigen"spaces". The probability of measuring a particular eigenvalue is the squared component of the state vector in the corresponding eigenspace, and the new state after measurement is the projection of the original state vector into the appropriate eigenspace. Instead of performing quantum-mechanics computations in terms of wave functions (kets), it is sometimes necessary to describe a quantum-mechanical system in terms of a density matrix. The analysis in this case is formally slightly different, but the physical content is the same, and indeed this case can be