gjphw (08/06/82)
There seems to be continual debate about the nature of time, the
possibility of time travel, and the issue of personal determinism. I
would like to advance some observations about our concept of time.
The present, common conception of time derives from the success of
classical mechanics (e.g. dynamics, falling rocks, projectile motion,
celestial mechanics, and special relativity). For all of these, time
appears as a simple parameter which can be reversed at will. This is
not the absolute time concept of Newton, but still a simple concept.
Quantum mechanics treats time in the same way as classical mechanics.
Since classical mechanics (or dynamics) is so successful at describing
and predicting phenomena, its philosophical assumptions are also
accepted. Metaphysics is implied by the physics. Time can then be
viewed as merely another dimension (or more exactly a coordinate "ict"),
similar to any of the spatial dimensions, in which we will one day
realize the freedom of motion. Travel through time is, in principle,
possible and, since all future is calculable, we are predestined to
follow this predictable path.
This view of time as reversible conflicts with other experiences.
People, and rocks, only age. What if time, as it appears in
thermodynamics, is treated as the paradigm? (Statistical mechanics
attempts to bridge the gap between dynamics and thermodynamics, with
more emphasis on the dynamics side of the subject.) I. Prigogine, in
"From Being to Becoming", argues essentially for this. Experience with
very complicated systems requires that time be a one-way parameter
(irreversible). In addition, the predictability of a phenomenon is
limited (entropy). A particular phenomenon cannot be predicted with
arbitrary precision as time proceeds from some initial conditions (this
situation is called weak time correlation). So, not only is time travel
into the past not possible, the future is not very calculable (or
predictable).
Having thought about this issue of time and determinism, the
concept of time derived from thermodynamics appears to be more
reasonable. While time irreversibility makes me uncomfortable with
science fiction stories about time travel into the past, I am consoled
by the idea that I am not predestined to follow a predictable path
through the future. How any of this relates to free will is open to
discussion.
Pat Wyant
ihuxn!gjphwG:wing (08/10/82)
One other thought on time (This might also be a response to Paradox, but I haven't read that article yet). Our past could already be formed by the future. Case in point: The Star Trek episode with Gary Seven shows the Enterprise traveling back in time to Earth. Because of what Gary Seven and the Enterprise do, the American nuclear warhead satillite blows up a bit over a hundred miles above Earth. Although Gary Seven at first thinks that they have changed history, William Shatner remarks that they have records of the specific event they caused to occur in their history database (no flames, please!) of that satillite blowing up just as they saw it. Paradoxes cannot occur. The One And Only, Philip L. Wing U.C. at Berkeley decvax!ucbvax!g:wing