The Thought Experiment
The Wigner's Friend thought experiment posits a friend of Wigner who performs the Schrödinger's cat experiment after Wigner leaves the laboratory. Only when he returns does Wigner learn the result of the experiment from his friend, that is, whether the cat is alive or dead. The question is raised: was the state of the system a superposition of "dead cat/sad friend" and "live cat/happy friend," only determined when Wigner learned the result of the experiment, or was it determined at some previous point?
Read more about this topic: Wigner's Friend
Famous quotes containing the words thought and/or experiment:
“One thought fills immensity.”
—William Blake (1757–1827)
“The man who invented Eskimo Pie made a million dollars, so one is told, but E.E. Cummings, whose verse has been appearing off and on for three years now, and whose experiments should not be more appalling to those interested in poetry than the experiment of surrounding ice-cream with a layer of chocolate was to those interested in soda fountains, has hardly made a dent in the doughy minds of our so-called poetry lovers.”
—John Dos Passos (1896–1970)