Time travel is a recurring theme in science fiction and an
appealing idea. There seems to be some support for the idea that we could, at
some point, move in time in the same way that we move in space, time being the
fourth dimension after the three spatial dimensions. I sometimes read that we
already travel through time, but in only one direction, forward, and then only
at established paces. The relativity of time to spatial movement, moreover, means
that those established paces can vary. If I am in a speeding space ship and you
are on earth, we will age at different rates and what will be present or future
for one of us can be past for another.
It seems to me, though, that the idea that we travel forward
in time is an illusion created by memory. My earliest clear recollection, for
example, is of climbing up on a windowsill and falling out into rose bushes
when, according to location and circumstances, I must have been about three
years of age. In passing, I’ll note that most of my distinct memories in life
involve mishaps. You could attribute this to the fact these are the sorts of
things that leave impressions or to the fact that I am an accident-prone klutz.
Both of these are probably true.
My memory of falling out of the window gives me the
impression that I was on a windowsill at one point and that I have gradually
moved forward to this point, at which I am sitting in front of a computer
hoping that I don’t fall out of my chair. But the “I” at the computer is not
the same “I” that fell into the rose bushes, in the same way that a tree is not
a seed or a sapling. There is no disjunction of identity in either case, but in
both cases what came later emerged from what came earlier and what came later
cannot coexist with what came earlier. A tree cannot also be a seed and a
sapling.
If I were to go back through the decades to when I was three
years old, I would be three years old, not my present advance age observing
myself as a toddler. To go back one hundred years would be to go back to a time
when I did exist, so I would not have existed in the year 1923. I exist in a
time that I did not exist. We don’t just walk through time. We are products of
time.
I think this has some interesting implications for the
concept of an eternal return. Let us say, for example, that the forward movement
of time is a result of a universe expanding from forces of repulsion in an inconceivably
densely packed unity. Eventually, the forces of repulsion would grow so weak
that the universe would begin to contract and time would run in reverse. But if
it is the same time running in reverse that previously ran forward, then the
same events would be repeated in reverse order. I would be a man of some years
and experience and then a three year old. But because I would be the same developmental
series backward, as well as forward, I would be experiencing time as moving
from past to future, even though someone outside the universe would see it as
running from future to past.
If the universe contracted again to the initial point and
repulsion caused another “big bang,” then the question would be whether the
expansion would follow the exact same trajectory, or would change in some ways.
In the first case, there would be no difference for me between my living
through events once and my living through those same events a million times. In
the second case, whatever would exist would be different from what exists now, including
me, if I could considered as existing at all. Of course, this is all
speculation. But the speculations all suggest the same thing: we are prisoners
of time and there is no excape.
No comments:
Post a Comment