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Bit from Binary Digit. What has information to do with reality?


Niels Bohr: distinguishing between 'observation' and 'registration'
John Wheeler Scientist
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Such an interesting point about what it is that brings an elementary quantum phenomenon to a close so you can say the definite result. It's a little like a trial or a title deed after it's all written out and printed: that's it. If the observation that you're making is registered in an indelible form, then that is really the completion of a quantum phenomenon. But if it's only in a temporary form, there's always the question whether it will disappear and whether what you thought was a result will not be undone. So, Bohr was very careful to talk about a phenomenon brought to a close by an irreversible act of registration. My wonderful colleague, Eugene Wigner, used to ask, in his Hungarian version; "What means irreversible?" And that's a matter of degree rather than [of] kind, as we see it today.

John Wheeler, one of the world's most influential physicists, is best known for coining the term 'black holes', for his seminal contributions to the theories of quantum gravity and nuclear fission, as well as for his mind-stretching theories and writings on time, space and gravity.

Listeners: Ken Ford

Ken Ford took his Ph.D. at Princeton in 1953 and worked with Wheeler on a number of research projects, including research for the Hydrogen bomb. He was Professor of Physics at the University of California and Director of the American Institute of Physicists. He collaborated with John Wheeler in the writing of Wheeler's autobiography, 'Geons, Black Holes and Quantum Foam: A Life in Physics' (1998).

Duration: 2 minutes, 4 seconds

Date story recorded: December 1996

Date story went live: 24 January 2008