TIME
TRAVEL,
LOGIC
AND
SPECULATION
What’s the logical point of view on
the possibility of the time travel at will to whatever time of the
relative past or future, with or without machine?
The analysis will be essentially dedicated to the assumption of the
travel in the future because its possibility seems less obvious than that of
the travel in the past. As it was
suggested by Pascal, it seems "easier to conceive that what already was
either still, than what was not yet be already".
A) SIMULTANEITY AND INSTANTANEITY
Above all, it should be noted that the
possibility of travelling in time supposes the capacity to cross the
"wall" of time. How to arrive
to such or such part of the past or the future if it is necessary "to take
the time" of reaching it?
Displacement in time should last, at most, only the " time of
Planck ", that is to say 10-43s. One can thus raise from the
start the character undoubtedly unsuitable of the expression "time
travel". But this problem will not
be developed nor analysed here. It is
not question either of answering the questions, however essential, of knowing
"where" -hyperspace, parallel universes, beyond, other
dimensions- are the times of
destination, nor "how" –Black holes/ White fountains, wormholes,
machines, quantum scanning...- to reach
them. Essential questions since they
compel to define an
"identity" of time.
This identity will be declined a priori according to three assumptions:
-time is the only way for an entity to be
different from itself and to occupy two different space’s positions. (Kant,
Heidegger, Dubois (theorem of time))
-time is the number of the movement according
to before and after (Aristotle)
-time is the expression of a causal relation
through concepts of " past, present and future "?
Objective: to play the game of the speculation
and to imagine the possibility of finding himself "instantaneously"
with such or such part of the past or the future. "Instantaneously"!
Consequence:
the individual is "simultaneously" what he is in his time and
what he must be or what he was in the invested time, according to whether it is
of the future or the past, and in so far as it is one time included in the
history, the time of existence, of the individual. Indeed, the instantaneity of the travel in time supposes the
effective and current realization of all the past and all the future. To reach the year 3001 at the moment, it is
necessary that currently is carried out what accounts for the year 3001, or
rather it is necessary that is carried out the year 3001. In the same way, to find itself in 1895
"at the moment", it is necessary that all that represents the moment
of the year 1895 that one invests, exists indeed somewhere, in this universe or
in another dimension, at the moment when these lines are written. To be allocated to the "traveller"
of time, one can say that at the same time he "is, will be and was".
To extend the logical movement, one can say that this individual "is"
simultaneously "his entire temporal development". Indeed, since he can at every moment decide
to go to whatever part of the past or of the future, one needs that all these
times all exist somewhere at the same time, i.e. "coexist", because
there is no formal reason to privilege some time rather than another.
B) DETERMINISM
To what does lead the need for
the current and total achievement of the past and the future?
To the absolute determination of
the development of “being” and “thought”.
More there is no place for chance and freedom since all is already
realized, or rather, all is carried out without any possibility for anybody
exerting on this realization least true control. It thus does not matter the question of the possibility of investing
instantaneously a time different from ours:
arrive what must occur.
To go at the end of the
reasoning, it should be admitted that the words registered here were always
determined and that this consciousness even, this reflexive return on the text being
written, is predetermined, and thus ad infinitum, any entity, any expression
carried in a universal inertia. Why the
enumeration isn't prolonged? Would the
author of these lines express some free-will?
Here in any case is the occasion of wondering about the capacity of
suggestion of the word and on the propensity of the mind to be caught with the
play of the reasoning until the absurdity. Absurdity?
C) PROOF OF THE IMPOSSIBILITY OF THE TIME TRAVEL
Assumption: possibility of the instantaneous
investigation of any time different from the present.
Consequence: current, effective,
simultaneous realization of all the past and all the future.
The future being currently carried out, there is at one more or less
remote time in the future, an individual who discovered the possibility of
traveling in time. From the moment of
this discovery until the infinite, one imagines easily that the man has all the
leisure to explore the times posterior and former to his own one. But then, how to believe that an infinity of
individuals having eternity to explore the vestiges of their past civilization
would not have left the least trace of their passage to one or the other time
of past which is common for us?
Highly improbable; this possibility can be assimilated to a universally
negligible probability in the sense of Borel.
Nevertheless, this demonstration does not have all the rigor of the
scientific reasoning.
It supposes initially that humanity will not perish. But how to believe that it can disappear
completely if it is permissible with a handle of men of going to take refuge in
one past or future time in the event of imminent universal catastrophe in their
present? Then, it is supposed that the
individual will have all the leisure to use this invention, and especially that
an infinity of individuals will profit from it. Easy to believe since humanity cannot perish, and that at a rate
of only one individual per terrestrial year during an eternity, to adopt a
pessimistic point of view, an infinity of individuals would have the occasion
to invest our centuries. Thank you,
Cantor!
Lastly, calculation of the desire, at these men of the future, to
discover the past of humanity concretely.
But one can speak without exaggerating of "need" to know the
past, if the man to come resembles even a little to the man of today. In any case, it seems that one cannot
imagine a thinking being, human or different, stripped of curiosity.
It is necessary to be let convinced by these arguments, while recognizing
their probabilistic character in the sense of Bayes/Ramsey.
D)
EXTENSION OF THE THESIS RELATIVE TO THE CHAPTER
INSTANTANEITY
AND
SIMULTANEITY
The first demonstration showed that the possibility of the time travel
implies "all the development” of any being at the same moment and at every
moment. Does one imagine the
"phenomenal" obstruction of the universe in such a case? Chaos reigns: all the possible events must
occur simultaneously. But where
"to put them"? One might as
well say that the vacuum and the silence alone would reign, because good-bye
time. Overflow of being! Too much of
all. All, nothing.
Unless... the coexistence of several universes, the
“multiverses”... Theory of the quantum
reduction of the universe by Hugh Everett III. A kind of extension of the “wave
of probability” from the micro to the macro level. All the possible variants in
the course of the events give birth to as many branches of universe.
The question is then to know if there exist bridges between these
universes and which is the nature of these means of communication.
Another answer to the problem of the "phenomenal" obstruction
could come from the existence of the "wormholes", or of the
"white fountains", these symmetrical and complementary structures to
the "black holes".
These assumptions make the object of another article.
E) ADDITIONAL ARGUMENTS
"AGAINST" THE POSSIBILITY OF THE
TIME TRAVEL
Having the preoccupation with an exhaustiveness, here some other arguments
which will make improbable or impossible the time travel at any part of the
relative past or future, with or without machine.
For Christian Grenier, "the time travel suffers from certain
contradictions with the most elementary logic, which draws aside it from the
scientific field". (the S.-F.,
readings with a future?)
"A barrier is drawn up, that of logic wanting that one cannot at
the same time be here and elsewhere", adds Van Herp. The simple possibility of the time travel is
a paradox and modifies the course of the events, as opposed to what Watzlawick
says in "The reality of reality":
"It retrogresses fifteen years (what takes to him, let us say, a
few minutes), stops the machine and leaves there, thus recovering in the course
from time... in a point where he is himself fifteen years old. If he is satisfied with looking at around
without causing any effect - namely, without fitting in any manner in causality
by an action or a communication - it will produce nothing strange. But as soon
as it starts to interact, the amusing and disconcerting consequences will
follow." Precisely, by his simple
presence, the time traveller interacts with his environment and is, ipso facto,
the cause of a chaotic phenomenon, a butterfly effect due to a disturbance of
the initial conditions, as could have discovered it Bradbury if he had been
until the end of its reasoning in "A thunder clap", not seeing that a
sudden appearance in the world is at least as disturbing as the fact of
crushing a butterfly. (in this novel, facetiously, the temporal butterfly effect is caused by the… dead of a
butterfly at the Jurassic!)
The paradoxes caused by a voluntary or involuntary act of the time
traveller constitute of course a new argument against the possibility of the
time travel;
the "grandfather" paradox -positive "and" negative
retroaction’s loops- in "Le voyageur imprudent" of Barjavel:
-
“He goes back in time.
-
He kills his ancestor?
-
Therefore he does not exist.
-
Therefore he doesn’t go back in
time.
-
Therefore he does not kill his
ancestor.
-
Therefore he exists.
-
Therefore he goes back in time.
-
Therefore he kills his
ancestor.
-
Therefore he does not exist.
-
Therefore he doesn’t go back in
time.
-
Therefore he does not kill his
ancestor.
-
Therefore he exists... "
and the paradox of “knowledge” in "The end of Eternity" of
Asimov:
- to go to seek in the
future an information which will be at its own origin in the past .
are the best examples.
Temporal butterfly effect, “grandfather” and ”knowledge” paradoxes are
nothing else than three versions of the same ontological paradox which can be
synthesized in the following way:
by its identity, i e. the distinction between past, present and future,
time gives its meaning to the assumption of travel ing in
time, but if the time travel is possible, it removes its identity, its
meaning at time, which results in to make "impossible" the time
travel. The alternative is: Time or
Time Travel; Time exists, ergo Time Travel doesn’t exist.
By a retroactive effect, these three paradoxes not only show that
contradictions appear because of the reintroduction of the logic after having
removed it, but precisely that the contradiction is “original”, the initial
expression “time travel” is auto contradictory!
This idea, that I have formalized in the first part of this article
(first version written in the mid 80’s) and in which I develop the
argument of the loss of the identity of
the time, has been proposed independently, but not formalized, by the twin
brothers Igor and Grischka Bogdanoff:
"If the voyage towards the past had been invented somewhere in the
future, we would surely have already received the visit of a man of the
future". This is an argument, still not formalized, that has been advanced by Stephen Hawking
who said that "The best proof that the time travel is impossible is that
we have not be invaded by some hordes of tourists of the future". In
addition, Hawking thinks that nature detests the machines to travel in time. It is an idea that he develops in his
conjecture of "chronological protection", according to which the laws
of physics prohibit the machines to travel in time: "each time somebody tries to make a machine to travel in
time, and whatever the device used for this purpose (a worm hole, a cylinder in
rotation, a "cosmic string", or anything other), just before the
device does becomes a temporal machine, a beam of fluctuations of the vacuum
crosses it and destroys it ". Hawking
showed that quantum fluctuations of fields would become infinite in the
vicinity of a mouth of a worm hole, -my argument of the "infinite temporal
overprinting" arrives at the same conclusion by a reasoning of pure logic
-, preventing the formation of time loops or destroying the traveller who would
approach a Loop of the time kind. Hawking called with humor that its
assumption "makes it possible to keep the world sure for the
historians".
The Bogdanoff
brothers advance another argument to cancel the possibility of the time
travel: "the entropy of a system
can be only increasing; in other words,
which we name "flow of time" is only a direct function of the entropy
to which all the systems (biological or not) are subjected. As it is impossible to reduce the entropy of
a system, it would be also impossible to reverse time and, a fortiori, to
travel in the past", (Keys for the science fiction).
Directly connected with the problem of entropy, the question of the
modification of the “total mass” of the universe due to the sudden apparition
or vanishing of a time traveler has been suggested by Robert Silverberg in “The
Time Hoppers”: this is clearly in contradiction with “e=mc²” and with the
experimental observations of Lavoisier establishing that “Nothing disappears, nothing appears, all is
becoming/changing”.
On a practical and an humoristic ground, the
possibility of the time travel would constitute a
funny explanation to the mysterious disappearing of entities all time/history
long.
Less powerful arguments against the possibility of traveling in time consist
in disparaging the interest of the time travel because the temporal
short-circuit, the absolute determinism, the temporal reduction and the
infinite temporal overprinting do not offer very amusing prospects to the
individual who wants to explore the past or the future. These prospects will be
developed in a forthcoming article.
Let us return finally to the assumption of the theory of the multiple
universes to note that it reveals ab absurdo the importance of the principle of
economy of nature and the relevance and the topicality of the remark of Leibniz
according to whom we evolve in "The best possible world". It seems that a universe without possibility
of traveling in time is the best possible world, because it presents the
optimum of existence.
F) COUNTER-ARGUMENTS
"FOR" THE POSSIBILITY OF THE
TIME TRAVEL
To allow some open perspective, and in a divergent, disrespectful
foot-of-nose towards the principles of the classical argumentation which wants that
positive arguments were first advanced, here, now,
the arguments which will make possible or even probable the time travel at any
part of the relative past or future, with or without machine.
Against the argument of Grenier and Van Herp, one can point out that the
barrier of logic wanting that one cannot at the same time be here and
elsewhere, is actually only one axiom, on what "rests" logic. A fundamental axiom cannot be shown. It contradicts thus not logic.
Against argument of Hawking proposing risks of infinite fluctuations of
quantum fields at the time of creation of the time travel machine, Deutsch and
Lockwood answer that infinites, which one knows that they are the obsession of
the physicists and the mathematicians, simply reveals an insufficiency of the
theory. Deutsch and Lockwood cancel
also the argument of Hawking-Bogdanoff-Dubois on the absence of invasion of
hordes of the future because the wormhole would make it possible to go up in
time only until the time of its creation and not beyond. Deutsch and Lockwood
also answer that there are perhaps currently kind time loops exploited by an
extraterrestrial civilization, but that this does not inevitably imply that it
wants to come to see us in its past.
And even then, the "time travelers" would go only in certain
"copies", branches, of the past.
Lastly, the traveler of time is not compelled to speak off that he is a
time traveller!
For Deutsch and Lockwood, " If the theory of the multiple universes
is exact, then all the usual objections with the time travel are founded on
erroneous models of physical reality.
Whoever rejects the idea of time travel must formulate a new argument,
scientific or philosophical".
Hawking itself reconsidered its first declarations and recently affirmed
in the press that he considered now the possibility of traveling in time.
Against the "entropy" argument of the Bogdanoff brothers, one
will object that nothing prohibits a local inversion of the entropy, the
existence of the most negligible particle is a testimony of that; and this is precisely, in the case of the
time travel, a local modification of the entropy, that is to say the own time
of the time traveller. The assertion of
Einstein:
"We, which believe in the physics, know all that the distinction
between past, present and future is only an illusion, even if it be
tough", comes reinforce the idea that the time has not the identity that
we it grant, and give thus some weight with assumption of possibility of
traveling in time. The interpretation
of Wheeler of the diagrams of Feynman goes in the same direction. Let us recall that this interpretation
consists in seeing reality like only one extremely complex universe’s line
already realized, i.e. for which does not pass time. The feeling of flow of time would be an illusion related to our
perception of reality.
One cannot not evoke the artist M.C. Escher, who managed to represent
and to make us penetrate in a universe of "impossible figures". It is a little what occurs with certain
mathematical theories and the accounts of time travel.
For Rudy Rucker, the reasons to draw aside the time travel rest on one a
priori: "It cannot appear
contradictions in the world; the time
travel and SL (supraluminic) displacement lead to contradictions; therefore there cannot exist the possibility
of time and SL travels in our world".
This argument presents for Rucker three weak points.
1.
The world itself is paradoxical
2.
It could exist a "police of the time"
which would prevent the use of the machine to create a paradox.
3.
There is the possibility of the multiple
universes, even if "... of course, strictly speaking, a travel in a
parallel world is not at all a time travel ".
" At a certain level, these paradoxes are a little more than
intellectual entertainments ".
Indeed, like the paradox of the impossibility of the movement of Zeno,
they highlight the schizophrenic character of the reality. Rucker adds that Relativity affirms that
there is no absolute space and time.
However the time travel requires an absolute time and an absolute
space. Consequently, the time travel
seems from the start prohibited by modern physics. But in addition to the fact that there are laws of transformation
which make it possible to pass from a frame of reference with another,
Relativity authorizes the travel in the past until a certain limit, and in the
future in an unlimited way, as shows it the paradox of the Twins of
Langevin. Would relativity contradict
itself?
For David Lewis, the time travel is possible. The paradoxes prove only that the world where the time travel
would be possible would be in a fundamental way stranger than that which we
believe being ours. He is the burning
defender of an author as Heinlein of which he finds the account "You them
zombies", perfect antithesis of the paradox of the grandfather,
self-consistent. The hero of Heinlein
goes up in the past and makes pregnant a girl who is not different than himself
before the operation which will make him change sex. The baby resulting from this on-consanguineous union is
transported in a past a little more still moved back to justify the birth of
the heroin-hero. Had Heinlein consumed some?
The fault of the temporal algorithm of Heinlein: the girl exists before being born since she
gives birth to herself; the hen before
egg. It is paradoxical in a sense more
extreme still perhaps than the fact of being sown by oneself. The existence of
the girl seems to come out of the causal loop "dad-baby". And yet, which difference with reality? Is the universe not at its own infinitely
regressive origin?
It is clear that what poses problem in the travel in time, that’s the
multitude of the paradoxes which it generates.
A reasoning “ab absurdo” consists in saying: reality cannot be put up with the paradoxes; however reality exists; therefore the paradoxes do not exist and the
travel in time either.
But reality is coherent only seemingly, it is basically irrational, as
us suggest it quantum physics and pure logic itself. Thus, the possibility of displacement in time is in perfect
agreement with reality. L.M. Krauss, in
"The physics of Star Trek", emits an argument of common sense: "As long as it is not refuted by the
scientific framework, that remains field of possible". It is what underlines also J. Gribbin in
"In search of the edge of time":
"Whatever the type of curve of space-time, the equations of
Einstein say to us exactly which distribution of matter and energy must
appear. The question is then: such a type of distribution of matter and
energy is possible?".
CONCLUSIONS
Despite of the optimistic arguments of the previous chapter,
I think I have developed the definitive argument that Deutsch and Lockwood are
waiting for: the ontological argument of the total
incompatibility between the definitions of time and the intrinsic character of
the moving in time. Maybe a mathematical translation would make it more
presentable, but the discursive formulation is perfectly convincing.
We could express it in an other way. As Bergson and
currently Prigogine develop it through the notion of “duration”, the matter is taken
in time, it is the fundamental definition of any kind of being. The development
and wear, characteristic of any form to be, are inconceivable out of any
temporal framework. The being makes
time, to be "IS" time in the sense of duration. The matter - and the human being is also
matter, development and wear- cannot
travel in time because it cannot travel through itself, it must be satisfied
with accelerating or slowing down the course of its development or its wear. It
is “prisoner” of the time, of a universal inertia without any possibility to
escape from it. Time travel is impossible because time cannot travel in itself,
“time cannot travel in time”. Time is prisoner of itself!
That’s what have shown Einstein and Minkowski through the concept
of "space-time continuum".
Lemaître will infer that any entity is blown off in a universal inertial
movement consecutive to a Big-bang.
Ironically, since, despite of his deep comprehension of the time’s
notion, he will draw inferences in contradiction with this deep notion, the
father of the modern idea of the time travel, H. G. Wells, will give a
spectacular description of this conception in the first chapter of “The time
machine”:
‘Can a cube that does not last for any time at
all, have a real existence?’
…`Clearly,' the Time Traveller proceeded, `any real
body must have extension in FOUR directions: it must have Length, Breadth,
Thickness, and--Duration. But through a natural infirmity of the flesh, which I
will explain to you in a moment, we incline to overlook this fact. There are
really four dimensions, three which we call the three planes of Space, and a
fourth, Time. There is, however, a tendency to draw an unreal distinction
between the former three dimensions and the latter, because it happens that our
consciousness moves intermittently in one direction along the latter from the
beginning to the end of our lives.' (The Time Machine)
At the
first reading, one is impressed by the spectacular anticipation of the
fundamental lesson of the theory of the Relativity of Einstein. In the same
spirit and the same geometrical conception than that of Einstein, Wells see
there an excellent argument to justify his option of the possibility of the
time travel.
But a deeper analysis reveals that the real
innovative and important thought is contained in the initial question: “Can a
cube…” which shows that reality is time and time is movement (and not only
number of the movement).
Irony: this hidden innovative conception of the
impossibility of a non-persistent being contradicts the geometric
interpretation of the obvious and more spectacular innovative space-time
conception and consequently the heart of this memorable fiction: the
possibility of the time travel. In fact, no more logical conclusion.
The reflection about the possibility of time travel, in addition to its
intellectual interest, makes it possible to get to the root of the
comprehension of the nature of time and reality.
So the determinism implied by the possibility of the time travel leads
us inexorably to the question of the “universal evolution process”; the
complexification of the universe is obvious. The question is: is it the
application of a predetermined program or the fruit of random combinations? The
first option gives birth, at the extremes, to the anthropic and theological
conceptions; the second option allows some kind of ghost of freewill or indetermination.
Annex:
The possible universal histories can be synthesized like this:
absolute non-being
!
qualitative jump
!
\!/
!
original singularity
(if not "non-being"
before B.B., there is the alternative also absurd of eternity with or without
"god"; infinite regression and quantum void/vacuum are variants of
eternity)
!
qualitative jump
!
\!/
!
matter
!
qualitative jump
!
\!/
!
life
!
qualitative jump
!
\!/
!
brain
!
qualitative jump
!
\!/
!
consciousness
!
qualitative jump
!
\!/
!
?
the less to the most complex stratum (each step in the evolution is a stratum)
but the important term is "qualitative jump"; and we have absolutely
no idea on the nature of it!
Are the entire evolution and
its qualitative jumps contained in an
original qualitative jump or are there a series of random qualitative jumps all
independents?
In the first case, each
stratum is the consequence of a preprogrammed qualitative jump, and we stay in
the absolute determinism; in this hypothesis of an initial singularity,
transcendental perspective, some people infer
the anthropic or the theological perspective which are “ad hoc”
explanations.
In the second branch of the
alternative, the evolution could be totally different because of totally
different qualitative jumps. This empirical perspective, based on immanence,
seems to be the less absurd of the two, if the attribution of a degree to the
absurdity makes sense!
NEXT DEVELOPMENTS
temporal short-circuit
absolute
determinism
temporal reduction
infinite temporal
overprinting (Dubois/Hawking)
positive/negative retroaction loops
temporal collision
infinite oscillation
of being (Grandfather paradox), paradox of knowledge, sensibility to the
initial conditions: one and the same paradox
Twin paradox of
Langevin
Doubling time(>< Relativity ?): does the solution
to this puzzle question the essential point of the theory of Relativity?
Time
travel, Logic and Speculation 2
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