Saturday, January 04, 2014

Free Will y ...

Bee has post on Free Will and Lumo has a response. Bee thinks thinks that this ancient philosophical debate might be important for physics because she thinks that an unreasonable belief in free will might be impeding progress in quantum gravity.

Sabine argues that since the known laws of physics are either deterministic or random the future is either determined by the past or God's dice game (if I may borrow from Einstein) so there is no room left for "free will".

From my point of view, this essentially amounts to defining free will out of existence. She then goes on to list "ten misconceptions" about the implications of her conclusion, which I mostly consider meaningless or worse. Lumo's view is closer to my own, but of course a critical point is how one defines or fails to define "free will".

One key point is whether one considers the future to be already defined or not. In ordinary thinking, the big difference between past and future is that the past is fixed and unchangeable, while the future isn't. Of course a lot of the future does seem pretty deterministic - the Sun will come up tomorrow, I'm pretty sure. Other stuff, not so much. I might go to see a movie tomorrow, or I might not. Whether or not I do may depend a lot on external events, but it also depends on some internal events - choices that I make. Of course Bee could argue that these choices I make have already been determined by some deterministic evolutions in the physics of my brain or by dice rolls already recorded in God's book of future games of chance but I find that claim lacking in potential empirical content - it's a claim that doesn't seem to be testable even in principle.

To me, however, there is a potential physical question at the core here: is our notion of the difference between past and future purely an illusion, or is it something real, something not yet captured by our apparently time symmetric laws of physics? Of course those laws don't seem to be exactly time symmetric - is that a clue or an artifact of circumstance?