X-Message-Number: 14189 From: Date: Thu, 27 Jul 2000 17:18:00 EDT Subject: Re: Identity Of Indiscernibles In Message #14170 From: "John Clark" <>: > >If (say) two atoms are widely separated in space, then they > > ARE distinguishable both in principle and in practice. > >How? If we were talking about apples and oranges it would be easy to tell if >I switched them around, but I claim I instantly exchanged two carbon atoms. >Prove I didn't. Instantaneous displacement is a sci-fi concept, there is nothing as this in the real world. The space of quantum mechanics is at the basis an infinite dimensional function space called the space of square integrable functions or Hilbert's space. That space maps in practice on a phase space with at least 3 space coordinates and 3 more impulsion coordinates. The Heisenberg's uncertainety rules come from that admixture of space and impulsion coordinates. If you want to bypass the problem, go directly to the function space. Ordinary space (euclidean space) has definitively an effect on these functions. A carbon atom in Boston is not the same as a carbon atom in New-York. Yvan Bozzonetti. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=14189