It is late
June—an absolutely glorious day. Low 20’s, a gentle breeze, a few fluffy
clouds. I can hear only the wind in the trees, a bit of traffic noise, and the
birds as I quietly paint the back deck. It reminds me of childhood days when no
friends were around. I’d play with a toy truck or some such, all the while
wondering about the big questions of life. What is “forever?” What is the “I”
that observes everything? “How old and how big is the universe?” Those kinds of
questions.
So, today,
on a day very similar to such days when I was a child, I ruminate as I paint.
Today my question to myself is “Is time travel possible?” I hate to break it to
you…. After all, we have much enjoyed stories where time travel is a feature
for a long time—both in literature and in movies. But, the sad news is: time travel within the
context of our universe is impossible. Doesn’t matter whether you are going
forwards in time, or back—it just can’t be done.
There is
one “sort-of” exception. According to relativity, the faster an object moves
the slower time passes for that object. Actually, that is verifiable;
apparently the satellites that control GPS have to be constantly adjusted to
make up for the fact that time is slower on them than it is for a stationary
object on earth. It is enough of a difference that unless these adjustments
were made, positions would drift by about 10 km a day. Look it up if you don’t believe me. So, if
one travelled in a spaceship at very fast speeds for a few months (spaceship
time), on the return to earth a hundred or so years might have passed. In a
sense, forward time travel is possible—but there is absolutely no way back.
Oh, I know
the old arguments: men have said we could never fly…travel to the moon…explore
the deepest oceans…climb Everest…build machines that can perform billions of
calculations in a second and potentially connect everyone in the world. All we
need is the right technology.
Misunderstanding
of the meaning of the space-time continuum that physicists and cosmologists
describe leads to some false assumptions. It stand to reason that if we can
freely travel in any of the other three dimensions—even all of them at the same
time—we ought to be able to travel through the fourth dimension at will. We get
confused because if we travel in any—or all—of the three basic directions, we
will arrive at a location different than our present position; in other words:
some place other than “here.” What we are doing is moving our three-dimensional
selves from one coordinate to another. Some would say that if it takes us ten
minutes to accomplish that readjustment of our coordinates then we have
travelled through ten minutes of time as well.
No, we
haven’t.
Whether we
move our bodies from one location to another during that ten minute interval or
we remain at rest makes no difference as far as the time dimension is
concerned. Time marches on, as they say. Some scientists describe time as an
arrow pointing in one direction. They complicate it by adding concepts like
entropy (a word taken from thermodynamics), but, however they muddle the
concept it still boils down to one directional travel—or something. Though many
equations work just as well backwards as they do forwards, in our universe an
egg dropped on the floor does not reassemble itself and hop back into our hand
complete. We simply cannot treat time as if it were a film strip that we can
play in reverse for our amusement.
Paradoxes
exist only in our minds; they do not occur in nature. If we observe that a
photon seems to be in two different places simultaneously that indicates that
we haven’t quite grasped the concepts of space and coordinates yet. Then
there’s the old chestnut of going back in time and murdering your grandfather
before your father was conceived. If you do so, then you don’t exist; and, if
you don’t exist, then you cannot go back in time and murder your
grandfather….and around and around we go looking for clever ways to get out of
our dilemma.
The fatal
flaw in our thinking, when it comes to time travel, is in thinking that the
past exists somewhere and the future exists somewhere else—and so what we are
doing by passing time is moving from a “past place” towards a “future
place.” Okay, I ask, where are these
“past places” and “future places”? If they have a concrete existence then, yes,
it may be possible to move from one to the other and visa versa. But, do they?
What, exactly, is the “past?” Or, better yet, where is it? I’ve read scientific descriptions of it as if time
were a loaf of bread that contains all events—and that we can experience past
and future events by cutting the slice of bread-time at an angle. I think it is
a bit difficult to physically affect a metaphor by using another metaphor, but,
that’s just in the world that I inhabit. I know there are many out these who
treat metaphors, such as “the creator,” as if they were physical entities. Does
thinking make it so?
Well, if
you go along with respected philosophers like Emmanuel Kant (Critique of Pure Reason), and physicists like Werner
Heisenberg (observation causes the collapse of probability) then you must
realize that nothing has an existence independent of our experience of it—at
least in any form that we can recognize.
“Reality” is the construct that our brain uses to reference and
catalogue the bombardment of sensory signals that it is constantly receiving.
Our brains frame our experience of time within the context of movement. But,
does it really have an existence independent of our experience of it? If it
does, then is the future thus preordained? Everything that can happen has
happened? I sincerely have a lot of trouble with that concept. Where did
free-will go then? Are we just automata following pathways that have been prepared
ahead of time?
Some talk
of alternate universes, where every possibility has fruition. That means that
even the smallest action that I take creates a complete universe where I did
not take that action. I have a bit of a problem accepting that. It seems to me
that it is just another clever way of getting out of the paradox of murdering
one’s grandfather before one’s father has been conceived. To suggest that both
events happened—the murder and the later conception—even if in different
universes (or space-time continuums to get fancy) is evading the question of
what is time, really?
Do all
“pasts” exist somewhere? Is there a definitive past? I’m sure that each of us
likes to believe that our memories of past events represent a physical reality.
But, where is this “past” located? Photos, journals, videos, artefacts, etc. do
not prove that a past “exists” now. What we are looking at, when we look at
such things, is in the present.
So,
stripping away all wishful thinking, we are left with the proposition that
neither the future nor the past has a “real” existence that we could, possibly,
travel to. I think that the “past” goes “poof!” as soon as it stops being the
“present.” It hasn’t “gone” anywhere—it just ceases being. Yes, we have
recordings of things that happened in the past, but, when the recordings were
made the “past” was really a “present.”
If I write a word “now,” that “now” cannot possibly be the same “now”
when you read it. The “now” when I wrote the word is long gone. So, we can have
records of “past” events, but, they were really “present” events when they
happened.
Same as the
future. It does not exist. Except, in the sense of potential. There is a good
possibility that at some point in the future I will stop writing this
paragraph. A pretty good possibility that I will eat a meal later in the
day—and that I will go to sleep sometime during the night and that the sun will
rise tomorrow. But, none of those things has an existence “now.” They might happen;
they might not. A chunk of ice could
fall from an overhead airplane and knock my brains out so that I will not
experience any of those events. But, in no case is there a physical place where
a chunk of ice is falling towards my head or where I will wrap this up, eat a
meal, go to sleep later, and then awake to a new day all having happened
“already” just waiting for me to experience them.
The only
“real” thing we can count on is the ever-present present and even that will no
longer exist when we die.
Here’s the algorithm:
Future –>
|
Now –>
|
Past
|
Possible events –>
|
Occurrence of specific event –>
|
Done
|
Non-existent probabilities.
(Potential)
|
Experience; expression.
Potential collapses into existence.
|
Nothing. It’s all gone.
|
