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Time travel and moral implications

Published: 7 August 2010 (GMT+10)
Image wikipedia.org The ‘twin’ thought experiment of relativity theory doesn’t have the same logical contradictions as time travel.
The ‘twin’ thought experiment of relativity theory doesn’t have the same logical contradictions as time travel.

John H from the USA wrote on the subject of time travel:

I’ve searched your site and have been unable to find any real discussion of either feasibility or Biblical consequences of this subject. Briefly, do you have any thoughts as to this as a moral question? We already know that, to some degree, time manipulation (by forces in general, not necessarily by human technical feat) is possible. In my studies of the Word, I’ve not really seen any thing which either through teaching/discussion or even vaguest inference addresses this. As beings of the Creation, the only requirement I can see is that we must exist in time instead of outside of it, as God does. However, that in no way addresses, to me, a requirement that it must be a specific place in time.

Thanks for your time.

In Christ,

CMI-Australia’s Dr Carl Wieland responded

Dear John

Thanks for your question.

It may be that it truly is a non-issue, since before it can be a moral question, it has to be shown that it is logically feasible. By that I don’t mean technologically, because the march of technology can always surprise us. But the laws of logic are not created laws, they just are—i.e. A cannot be non-A: the law of non-contradiction.

As my colleague Dr Jonathan Sarfati puts it—rather, “logic is the way God thinks; furthermore, as has been pointed out, ‘Either the logic of revelation is our logic or there is no revelation’1 This also solves some of the silly omnipotence paradoxes that some atheopaths bring up, i.e. a married bachelor or a rock too heavy for an omnipotent being to lift are logical contradictions, and this doesn’t change by putting the words ‘God can …’ in front of them.”

(See also If God can do anything, then can he make a being more powerful than himself? What does God’s omnipotence really mean?)

I would suggest, then, that time travel is not logically feasible. Consider this: if you could travel into the past, you could be driving a car that ran over one of your ancestors before he/she had reproduced, and thus you would never have existed, so could not have travelled into the past to kill that ancestor. So it would appear that for us to fret about the moral implications of this may be as pointless as speculating about whether it is immoral for a spinster to divorce.

By way of aside, secular theorists have long been tantalized by the notion of whether time travel could ever be possible. The only way out of this logical paradox issue for them has been to fall back on the ‘multiverse’ interpretation of quantum mechanics (QM)—the bizarre notion that there exists an infinite variety of alternative universes, such that every other alternative that can happen does happen somewhere. See for example Multiverse theory—unknown science or illogical raison d être? (It is important to differentiate between QM and a particular interpretation of it—QM as such has been experimentally well attested and there are alternative, less bizarre interpretations of QM. See also the articles under Quantum mechanics—What is it, and how does it fit with the Bible? as well as A new age of quantum madness relevant to this issue) So rolling a die and getting 1 would mean there would have to be 5 other universes in which the same throw happened, each with a different outcome. (Even weirder—some even maintain that at the moment the die is thrown, the 5 alternative universes are created. Hmmm … ) So how is this ‘multiverse’ (or ‘parallel universes’) notion supposed to make time travel logically feasible? It does so by allowing you to go back and run over that ancestor without any ramifications for the present, because it occurred in a parallel universe to this one.

Time manipulation, to which you refer, is not the same as time travel, of course; you are presumably referring to the well-known effect of time dilation or contraction via relativistic effects. This is well attested to by experiment and everyday experience (GPS would drift by metres each day if not corrected for time contraction relative to the Earth’s surface where gravity is stronger), and is the basis of the two leading notions for resolving the starlight-travel-time issue in creationism. But it does not involve time travel—time would flow the same in each frame of reference.

The famous ‘twin’ thought experiment is worth mentioning, in which one twin stays behind on earth and the other travels in a rocket ship close to the speed of light and comes back again to find that relative to his own experience of how much time has passed, his twin has aged much more than he. That does not involve any logical contradiction, and something like that could conceivably take place (and does, on a smaller scale—if two twins lived in a high and low altitude area respectively, then due to the time-distorting effects of gravity, since each experiences a different strength gravitational field, one would age faster than the other—only the differences would be immeasurably minute.) Such time dilation is also not a moral issue, since time flows normally for each of them, and they are responsible for the moral choices they make within their own time-space reference frame.

One final thought in passing, back to (pun intended) the issue of whether time travel will one day be possible—it has been pointed out more than once that the strongest argument against it might be: “Where are all the tourists from the future?”Smilies

Kind regards,

Dr Carl Wieland
Managing Director
Creation Ministries International Ltd (Australia)


  1. Hoeksema, H., The Clark – Van Til Controversy, 2nd edn, Trinity Press, Unicoi, TN, 2005. Return to text.

Helpful Resources

Readers’ comments

Christopher M.
Great article! I also love the "tourist argument" at the end (I'm kind of surprised that I never thought of it that way). However, there is one aspect of time travel theory that you didn't mention here. It's somewhat popular in science fiction (and sometimes that carries over into real world theories): the predestination paradox.

I'm sure you know what I'm talking about, but I'll explain for those who aren't familiar with it. It suggests that changing the past isn't possible (even if we could travel to the past) because any attempt we make to change it would have already happened in the timeline and would have no effect on events or it could turn out that your interference is what caused the event in the first place. That's a little complex of an explanation so I'll give you an example from Wikipedia: In 1850, Bob's horse was spooked by something, and almost took Bob over a cliff, had it not been for a strange man stopping the horse. This strange man was later honored by having a statue of him erected. Two hundred years later, Bob goes back in time to sight-see, and sees someone's horse about to go over a cliff. He rushes to his aid and saves his life. (here's also a few famous examples, Spoiler Alert!: http://en.wikipedia.org/wiki/Predestination_paradox).

According to the same page, there are a few different versions of the predestination paradox, but that one is a basic example. I know there is the issue of causality in the logic of this idea (which the article also mentions in one of the pop culture examples), but I'm curious about your thoughts. Thanks.
Carl Wieland
Thanks for your positive comment about the item in general. I may be missing the point, but I would have thought that it begs the question: If travelling back in time to when my father lived were possible, why would it be impossible for me to kill my ancestor? The logical paradox to me only arises because of the idea of time travel, and I suggest that the examples given simply affirm that it is time travel itself which is logically paradoxical, with the only way 'out' being the even more bizarre 'parallel worlds' notion.

All in all, while such speculation is fascinating, perhaps too much of it may not be the best use of one's (wait for it :-)) time.
Judie S.
The only way time travel could be possible (which I neither say nor believe is possible) would involve an inability to change the past, such as someone going back to stop Lee Harvey Oswald from shooting John F Kennedy & discovering only then that there WAS another shooter. (Conspiracy theorists rejoice!)
Actually, I did write a time travel story ('Day One', published September 1986 issue), about a scientist whose time machine wouldn't go even 10,000 years back! I have written another, called 'Day Forty-one', sending him back to when the rains stopped and the Earth was covered.
Geoff B.
I love the simple logic of “where are all the tourists from the future if time travel became possible”. It is like the reincarnation argument of where have all the souls come from for today’s population if they are all recycled.

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