Wheeler's delayed choice experiment is a thought experiment in quantum physics proposed by John Archibald Wheeler in 1978. The results Wheeler predicted have since been confirmed by actual experiment.
Wheeler's experiment is a variation on the famous double-slit experiment. In Wheeler's version, the method of detection used in the experiment can be changed after a photon passes the double slit, so as to delay the choice of whether to detect the path of the particle, or detect its interference with itself. Since the measurement itself seems to determine how the particle passes through the double slits – and thus its state as a wave or particle – Wheeler's experiment has been useful in trying to understand certain strange properties of quantum particles. Several implementations of the experiment 1984-2007 showed that the act of observation ultimately determines whether the photon will behave as a particle or wave, verifying the unintuitive results of the thought experiment.
Famous quotes containing the words experiment, choice, delayed and/or wheeler:
“The playing adult steps sideward into another reality; the playing child advances forward to new stages of mastery....Childs play is the infantile form of the human ability to deal with experience by creating model situations and to master reality by experiment and planning.”
—Erik H. Erikson (20th century)
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—James L. Hymes, Jr. (20th century)
“When the people saw that Moses delayed to come down from the mountain, the people gathered around Aaron, and said to him, Come, make gods for us, who shall go before us; as for this Moses, the man who brought us up out of the land of Egypt, we do not know what has become of him.”
—Bible: Hebrew, Exodus 32:1.
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—Ella Wheeler Wilcox (18501919)