Wednesday, May 13, 20093:00 PM - 4:00 PMPhysics Auditorium (TA-3, Bldg. 215, Rm. 182)|
CNLS-QUANTUM DISTINGUISHED LECTURE: Entanglement, Quantum Darwinism, and the Fate of Jimmy Hoffa
Charles BennettIBM Yorktown
The most private information, exemplified the path taken by a particle in a interferometer, exists only conditionally and temporarily—after the experiment is over even God has forgotten what "happened". Less private are classical secrets, facts known only to a few, or information—like the lost poems of Sappho—that once was public but has been lost over time. Finally there is information that has been replicated and propagated so widely as to be infeasible to conceal and unlikely to be forgotten. Modern information technology has caused an explosion of such information, with the beneficial side effect of making it harder for tyrants to rewrite the history of their misdeeds; and it is tempting to hope that all macroscopic information is permanent, making such cover-ups impossible in principle. However, by comparing entropy flows into and out of the Earth with estimates of the planet’s storage capacity, we conclude that most macroscopic information—for example the pattern of sand grains on an ancient beach—is impermanent, becoming irrecoverable in principle from evidence on Earth. Depending on the diligence and forgetfulness of their enemies, the fate of mysteriously disappeared persons such as US labor leader Jimmy Hoffa, thought to have been murdered in 1977, may by now have acquired this ambiguous epistemological status.
Host: Jon Yard