A BREIF HISTORY OF TIME by Stephen Hawking
I finally figured out what physicists mean by "determinism".
Hawking says that predictability is required for "scientific determinism"
(start of chapter 4). He defines "scientific determinism" as meaning that
something that will happen in the future can be predicted.
Interestingly, he admits later, that even the uncertainty principle
does not rule-out another kind of determinism, and says that quantum mechanics
may very well allow the universe to be deterministic (Conclusions). He
says:
" These quantum theories are deterministic in the sense that they give
laws for the evolution of the wave with time. Thus if one knows the wave
at one time, one can calculate it at any other time. The unpredictable,
random element comes in only when we try to interpret the wave in terms
of the positions and velocities of particles. But maybe this is our mistake:
maybe there are no positions and velocities, but only waves. It is just
that we try to fit the waves to our preconceived ideas of positions and
velocities. The resulting mismatch is the cause of the apparent unpredictability."
It is the type of determinism that only implies a unique, mechanical course
for the universe, that I ascribe to. Predictability is out of the question
and irrelevant. The human brain can not predict the future and insted creates
an illusion of choice and free will. This is a survival trick that is based
on 4 billion years of natural selection and serves people well. We can
recognize the fact of determinism, but still be left to behave as if we
have free will. I recommend Dan Dennett's Elbow Room (see
a review
by Danny Yee) as the best available discussion of free will. (I have additional
information about Dennett and Determinism scattered around here
and there.)
I think the intrusion of physicists into the game of publishing books about
the nature of consciousness is mainly due to the fact that physicists (like
all of us) feel like they have free will but at the same time they see
their models of the universe painting a picture of determinism. In this
century various physicists have constructed an endless stream of "escapes
from determinism" and now they want to show how to save consciousness from
the advancing progress in reducing mind to brain.
Hawking's discussion of the Anthropic Principle and Arrows of Time (particularly
the Psychological Arrow of Time) is very good (Chapter 9). Unfortunately,
he is so ignorant of brain physiology that he has to describe the Psychological
Arrow of Time in terms of computer memory! His argument easily applies
to human brains. I should send him a copy of Johnny Neumann's book (The
Computer and the Brain) and Crick's (The Astonishing Hypothesis) to show
him how some other physicists have been able to deal with the brain, but
I'd hate to risk creating another Penrose.
See a
comment about my comments on determinism.
Go to John's
Book Page.
Go to John's
Home Page.
send email to:
John William Schmidt