International Writers Magazine: 21st Century
Science and the Problem of Time Travel
the 2004 film "The Butterfly Effect" the movies
main character, Evan Treborn, finds that he can travel backward
in time and change past events in his childhood, which in turn result
in altered future outcomes. The scenario itself is hardly novel
and appears in numerous works of theatrical as well as literary
fiction. But does the concept of time travel belong solely to the
realm of science fiction or is it a possibility?
In the essay "Time
Travel: Possible or Impossible?" John Hospers endeavors to show
that time travel (at least in the sense of traveling backward in time)
is logically impossible based on contradictions such a proposition would
create. (Burr / Goldinger 505-508) To present his argument, Hospers
uses the example of traveling from January 1, 1962 A.D. to the year
3000 B.C. the time at which the Egyptians built the Great Pyramids
and discusses several apparent contradictions within it.
The first contradiction Hospers identifies is simple: one can not be
both in 20th century A.D. and in 30th century B.C. at the same time.
He goes on to suppose that on one day, January 1, 1969, one is in the
20th century and that on January 2, 1969 one travels back in time to
some day in 3000 BC. Here, also, Hospers finds a contradiction: "for
the next day after January 1, 1969 is January 2 1969. The next day after
Tuesday is Wednesday (this is analytic
) You may not live past
January 1, but whether you do or dont the next day (by definition)
will be January 2." (Burr / Goldinger 506) While for Hospers it
would be logically possible to find oneself in the environment of 20th
century A.D. on one day and inexplicably in the environment of 30th
Century B.C. the next, the day after today would still be tomorrow.
Lest Hospers argument be taken for one of semantics, he reiterates:
When you say that it is logically possible for you (literally) to
go back to 3000 BC and help build the pyramids, you are faced with the
question: Did you help them build the pyramids or did you not? The first
time it happened you did not: you werent there, you werent
All you could say, then, would be that the second time it
happened, you were there
But now we are speaking of two times,
the first being 3000 BC and the second time being AD 1969. ((Burr /
Hopsers argument is a rational one. It matters not that time travel
is as yet empirically impossible because even if one could experience
being at one moment in 20th century A.D. and at the next 3000 B.C.,
reason would override any such sense experience as logically impossible.
The argument rests on three premises: That one cannot exist simultaneously
at two different points in time; that time by definition moves only
forward; and that the past, having already happened, can not be changed
(you cant make what has happened not have happened). But what
conclusion would one be led to make if any of Hopsers premises
were shown to be in error or to put it in the terms of the skeptic
how does one know that any of the three premises are true?
This question, "how does one know truth from falsity?" requires
that a criterion or standard by which to judge the truth or falsity
of a proposition be used. The sort of "global skepticism"
employed by Sextus Empiricus in "The Problem of the Criterion"
denies any such criterion is discoverable by virtue of circular reasoning.
A.C. Grayling, on the other hand, provides an understanding of skepticism
which identifies it as an epistemological tool rather than denial of
any claims to knowledge. Grayling writes:
Scepticism defines one of the central problems in epistemology, namely,
the need to demonstrate how knowledge is possible. This is done
meeting the challenge to show that skeptical considerations do not after
all defeat our best epistemic endeavors.
skepticism is best understood
as a challenge, not as an agniological claim that we do or can know
This approach to skepticism is a sort of "scientific skepticism"
which requires a solid, justifiable body of evidence to substantiate
knowledge claims, rather than absolute certainty.
Returning to the question of time travel, let us look at each of Hospers
premises under the discerning lens of skepticism. The first hypothesis
then is: One cannot exist simultaneously at two different points in
time. It is related to the second hypothesis, that time, by definition,
moves only forward. In Hospers opening paragraph he warns that
it is dangerous to assume that the same language that is meaningful
in reference to space will be so meaningful in reference to time. It
may be justifiable to believe that we can not exist simultaneously at
two different points in space, but is this same assumption applicable
in time-language? That depends on what exactly time is. On this point,
the jury is still out. Albert Einstein described time simply as what
a clock reads. Even if similar properties regarding location apply to
time as to space, the property of spatial locality may be counter-intuitive.
Bells Theorem provides evidence that once objects interact, however
briefly, they remain connected even after they are pulled apart. Put
simply, locality (the principle that an event in one place can not simultaneously
effect an event in another place) is a non-reality that distance
in effect is an illusion and that everything and everyone is in one
"place". Computer scientist James Culbertson has speculated
that consciousness is in fact a relativistic feature of the space-time
continuum. According to his theory, "Spacetime does not happen,
it always exists. It is our brain that shows us a movie of matter evolving
Special circuits in our brain create the impression of
a time flow, of a time travel through the region of spacetime events
connected to the brain." (Scaruffi, http://www.thymos.com/science/qc.html)
If the body of evidence bears out in favor of theories such as these,
it may be not only possible to exist in different points in time simultaneously,
but impossible not to.
Trefils "Guide to Pseudoscience," classifies ideas in
three categories that he describes as being like concentric circles.
In the "center" are universally accepted ideas which have
a large body of evidence to support them. Beyond the center is the "frontier",
which feeds new ideas to the center. Beyond the frontier lies the "fringe"
containing ideas with little hard data to support them and where generally
accepted scientific knowledge seems not to apply. The fringe does however
supply ideas to the frontier and may be accepted provided the data to
support them and/ or technology to investigate them becomes available.
While Culbertsons "spacetime" theory may still rest
on the outer limits of the frontier it posits another hypothesis to
guide the search for evidence.
The last premise of Hospers argument is perhaps his strongest.
Hospers states: "This is an unchangeable fact: you cant
change the past. That is the crucial point: you cant make what
has happened not have happened." This indeed does appear to
be a logical contradiction. To explore it let us look again at the example
in the opening of this analysis, of the scenario in the film "The
Butterfly Effect" in which the main character returns in time to
events in his childhood and changes them. In Culbertsons reality,
spacetime events are static and ever-present. The flow or succession
of time is much like an illusion, simply a way of ordering events. Our
experience of these events hinges on our brains conscious connection
to such events. Could it not be possible to forge a new connection to
one of these events? In the film, Treborns time travel is achieved
through a phenomenon of memory assimilation. By concentrating on journals
he has kept of past events, he is able to literally (not figuratively)
re-live these events, while retaining his present knowledge of the eventual
outcome. Once a new choice has been made in one of these past events,
his brain re-assimilates new memories of that event and all succeeding
events (evidenced by scar tissue revealed on a CAT scan in one such
timeline) thus forming a new timeline of events. Unlike Hospers
example, where a change in past events indicates that the first time
an event happened it happened one way, and the second time it happened
a different way creating two different times, the scenario in the "The
Butterfly Effect" gives a description of reality that is rather
idealist in nature. It appears as if the characters mind is the
nature of his reality and by re-organizing the neural patterning in
his brain he is able to manipulate that reality. For the idealist, the
past would not necessarily be unchangeable.
In a more traditional or "central" view of spacetime and time-travel
science, the conditions which would make time travel possible do not
violate any accepted physical laws. Einsteins theory of special
relativity not only predicts that time travel to the future is possible,
but indicates that reverse time-travel may also be possible through
a sort of warping of the spacetime continuum, causing it to loop back
on itself. A person or object able to travel along this loop would in
essence be able to travel to a previous point in time. In this case
Hospers final premise does cause a paradox, commonly referred
to as "the grandfather paradox." Consider that you are able
to go back in time and kill your grandfather before he has fathered
your mother and consequently you are never born and can not travel back
in time to kill your grandfather. Some, Hospers among them, would conjecture
that because of this logical paradox, time-travel into the past is not
There are, however, other theoretical answers to this paradox. One such
idea is that the universe must have something like a law of continuity.
This law would prevent a time traveler from changing the past. One may
be able to travel to the time of the building of the pyramids, or the
childhood of ones grandfather, or ones own childhood, but
no changes to this past time could be made. This argument is shaky at
best, because the simple fact that you are at an event in time that
you were previously not in is in itself a "change." The other
common response of proponents to time-travel is that one who travels
to a past time was in fact there at that time, but was not aware that
they were there until they traveled back. This type of solution to the
paradox may be logical, but it is highly unlikely because it would necessitate
the universe operating in some very unusual ways. This cant be
ruled out categorically, but since there is no evidence which would
justify ones belief in this unusual operation of the world around
us, it would not be reasonable for one to assume its truth.
The conclusion on time-travel would seem to be, at this point in time,
inconclusive. Carl Sagan summed it up by saying,
maybe the joint effort of all those involved in this debate
has at least increased the respectability of serious consideration of
the possibility of time travel.
Of course we're not really
at that stage; we don't know that time travel is even possible, and
if it is, we certainly haven't developed the time machine. But it's
a stunning fact that we have now reached a stage in our understanding
of nature where this is even a bare possibility. ("Sagan on Time
Burr, John R. and Milton Goldinger. Philosophy and Contemporary Issues.
New Jersey: Prentice Hall, 1996
Herbert, Nick. Interview with Dr. Jeffrey Mishlove "Consciousness
and Quantum Reality with Nick Herbert, Ph.D". Thinking Allowed:
Conversations On The Leading Edge Of Knowledge and Discovery With Dr.
Jeffrey Mishlove. http://www.intuition.org/txt/herbert.htm. 1998
"Sagan on Time Travel". http://www.pbs.org/wgbh/nova/time/sagan.html
Scaruffi, Piero. "Quantum Consciousness". http://www.thymos.com/science/qc.html
The Future Pages
all rights reserved - all comments are the writers' own responsibiltiy
- no liability accepted by hackwriters.com or affiliates.