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Re: Heisenberg uncertainty principle for macroscopic objects



But I thought that Margaret's question was about <incoherent> assemblages
of particles. Here one has two problems: (1) The probability of a number
of particles tunneling; (2) The probability that the particles, after
tunneling, reassemble with the same structure as before tunneling.

Anyone want to do experiments with bacteria beams?
Regards,
Jack

Adam was by constitution and proclivity a scientist; I was the same, and
we loved to call ourselves by that great name...Our first memorable
scientific discovery was the law that water and like fluids run downhill,
not up.
Mark Twain, <Extract from Eve's Autobiography>

On Fri, 17 Dec 1999, Vern Lindberg wrote:

I don't know about elephants, but December's Physics Today cites
Zeilinger's report in Nature 401, 680, 1999 about experimental evidence of
interference of Buckyballs (C-60) through "slits 50 nm wide and 100 nm
apart." Sounds like a good article to follow up since it also talks about
the buckyballs "retain[ing] their quantum coherence" and being ideal for
exploring the "boundary between quantum and classical physics."

It's more years than I care to count since I studied (or taught) quantum
mechanics, so I need a bit of help with a discussion I am having ... I
had thought that the standard popular science type discussion of
Heisenberg's uncertainty principle, where it is claimed that there is a
ridiculously small but non-zero probability that an elephant could
quantum-tunnel through a wall, was falacious because the uncertainty
principle doesn't apply to a macroscopic, incoherent assembly of
particles like an elephant. Am I wrong?
Cheers
Margaret


Dr. Vern Lindberg 716-475-2546
Department of Physics Fax 475-5766
85 Lomb Memorial Drive
Rochester Institute of Technology Computer Haiku
Rochester, NY 14623
A file that big?
It might be very useful.
But now it is gone.