From: Henry Baker <hbaker1@pipeline.com> To: Ray Tayek <rtayek@ca.rr.com> Cc: math-fun <math-fun@mailman.xmission.com> Sent: Saturday, March 21, 2009 4:59:49 AM Subject: Re: [math-fun] If We Have Free Will, Then So Do Electrons Hopefully, these upcoming lectures will appear as Princeton University podcasts, which you can get for free & automatically using iTunes (or other podcast receiver): http://www.princeton.edu/WebMedia/podcasts/ At 01:24 PM 3/20/2009, Ray Tayek wrote:
http://science.slashdot.org/article.pl?sid=09/03/20/1229233
snahgle writes "Mathematicians John Conway (inventor of the Game of Life) and Simon Kochen of Princeton University have proven that if human experimenters demonstrate 'free will' in choosing what measurements to take on a particle, then the axioms of quantum mechanics require that <http://arxiv.org/abs/quant-ph/0604079>the free will property be available to the particles measured, or to the universe as a whole. Conway is giving <http://www.princeton.edu/main/news/archive/S23/69/84A24/index.xml?section=announcements>a series of lectures on the 'Free Will Theorem' and its ramifications over the next month at Princeton. A followup <http://www.ams.org/notices/200902/rtx090200226p.pdf>article strengthening the theory (PDF) was published last month in Notices of the AMS."
--- vice-chair http://ocjug.org/
I'm not sure what to make of Conway's paper. He concludes that a particle's response to a measurement is not determined by the past history of the universe. That's half-right. From the physicist's understanding of quantum theory, the past history determines the probabilities of the possible values of a measurement, but then the actual choice is completely random. So if one wishes to say that this randomness is a consequence of a particle having free will, that interpretation is surely irrefutable. Conway remarks that "... it is often said that the probabilities of events at one location can be instantaneously changed by happenings at an- other space-like separated location, but whether that is true or even meaningful is irrelevant to our proof, which never refers to the notion of probability." This notion, quite common in physics popularizations, is completely false. Indeed were that not so, we would already have faster than light communication. The situation is that a source S produces a pair of particles that are detected at A and B at space-like separation, so that A and B cannot influence each other (if you believe causality and relativity). It can happen that the measurements at A and B are correlated, e.g. if the z components of spins are measured, A has spin up if and only if B has spin up. These correlations become evident only when the recorded measurements are brought together and compared. The cause and effect relation responsible for such correlations is the common origin of the particles at S. There is no possible measurement at A that can be influenced by what happened at B. -- Gene