From: utzoo!decvax!ucbvax!faustus
Newsgroups: net.physics
Title: Quantum Mechanics Vs. Special Relativity
Article-I.D.: ucbvax.807
Posted: Sun Feb  6 13:53:38 1983
Received: Mon Feb  7 05:39:07 1983



	There is one interesting example of seeming FTL information
transmission that, as far as I can tell, has not yet been explained.
This is the phenomenon of the collapse of the wave function for
a particle. When there is a particle in a certain region of space,
its position is described by a wave function which when squared gives
the probability of finding the particle in any given place. When 
a measurement is made, the wave function is modified to reflect the
new state of knowledge: if the particle is there, the wave fn becomes
1 at that point and 0 elsewhere. It is concievable, then that given
a wave function that extends over a certain extent of space, two 
measurements can be made that are far apart in space and close 
together enough in time that there is no causal link between them
(is this called 'time-like seperated'?) Then, one is faced with
two alternatives: either there is a possibliity of finding the 
particle at both points (as there has not been enough time for
the wave fn to convey the fact that the particle has been found
at one point, and therefore cannot be anywhere else, sort of...)
and thereby violate conservation of lots of things, or the 
wave function could instantly collapse everywhere and make sure
that the particle is found in only one place, but introduce
FTL data transmission. Einstein was quite upset about this 
paradox, understandably, and so were a lot of other physicists,
but I don't think it has been resolved yet.

	Wayne Christopher
	faustus@berkeley
	ucbvax!faustus