X-Message-Number: 20884 From: "michaelprice" <> References: <> Subject: Identical objects Date: Thu, 16 Jan 2003 12:22:55 -0000 Robert Ettinger says: > If (say) two electrons are at two different locations, > and are otherwise identical by all known observation > techniques, just say so--"They are identical, as far as > we can tell, except for location." The far "as we can tell" qualification is misleading because we can actually *prove* whether two electrons (or two anythings) are identical. Simply determine whether they are subject to the Pauling Exclusion Principle (x)or can form a Bose-Einstein condensate together. If the objects in question have *any* differences (*including* any currently beyond our powers of observation to resolve) then they will exhibit neither property. It's as true for electrons as it is for elephants. The implications of this well attested physical property are not widely appreciated. For instance it disproves the quaint SF notion that subatomic particles can contain miniuniverses. Also the idea that subatomic particles contain wheels-within-wheels, since we would expect their internal 'settings' to vary from particle to particle and hence forbid the Exclusion Principle or B-E condensation. So I think Ettinger's conclusion is false: > Finally, if you choose to say that A and B share identity if > they are sufficiently similar, then your similarity cut-off point > would appear to be arbitrary. No, similarity is an absolute property, by my above argument. Either two things are identical or they are not, and this is an in principle, testable physical property, not some abstruse, philosophical point. > You could just fall back on the "quantitative approach" and > simply list the differences and degrees of difference, without > making any qualitative claim or label. But, as we have seen, identity is a qualitative property, not a quantitative one. It's all or nothing, not a matter of degree. > The fact is, "identity" remains an unsolved problem, and > possibly one which does not have any satisfactory solution. Physically identity is a solved problem. In fact identity goes beyond this - and what follows is quite unbelievable, I'll be the first to admit, to all but (some) physicists & chemists: If we have two objects, A & B, which we have determined to be identical by the above test, then it actually makes no sense to distinguish between them since, according to Feynman's path integral approach to quantum mechanics, identical objects are swapping positions with each other all the time. We don't notice this most of the time because the effects produced are very slight, but two identical objects will produce interference patterns that differ from the interference patterns produced by non-identical objects. [Trust me, I'm a physicist! :-) or read Feynman's "QED: the strange theory of the light and matter" which is a layman-readable account of quantum theory.] Now, I can almost hear the groans of Steve Harris et al, "what the hell has this to do with cryonics?" Well, some people (such as Ettinger, I think) believe that physical continuity is important for the survival of identity. If a copy of me in cryostasis were made then the original would be "me" and the copy would be not "me", but 'just' a copy. What physics is telling us, though, is that we can't distinguish between the two identical objects (including cryostiffs) in any physical or philosophical way. One is not the original and one a subsidiary copy. They are both of equal validity, with equal claim to originality. A copy *is* the original, philosophically, physically and informationally. As Francois said: > So if you have two objects which are perfect copies of > each other, then you don't have a copy and an > original, you have two originals. Cheers, Michael C Price ---------------------------------------- http://mcp.longevity-report.com http://www.hedweb.com/manworld.htm Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=20884