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Con (against)
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The Contender
Pro (for)
7 Points

Will (Reverse) time travel ever exist?

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Voting Style: Open Point System: Select Winner
Started: 2/5/2016 Category: Science
Updated: 8 months ago Status: Post Voting Period
Viewed: 422 times Debate No: 86144
Debate Rounds (4)
Comments (3)
Votes (1)




Won't really bother with rules because they are a waste of time.

Hope you accept, it will be fun.

Pro first if you like.


I thank Con for the challenge, a challenge I look forward to.

I've always been unwilling to do debates here, but then again, why not try something new?

Let us commence.
Debate Round No. 1


Here are some main reasons why reverse time travel will never exist:

1. One of the main ways it has been suggested that we can travel back in time is through wormholes ("A wormhole is a theoretical passage through space-time that could create shortcuts for long journeys across the universe."), however reverse time travel via this method has been disproved by feedback radiation, feedback radiation is when as a worm hole expands (To travel through) naturally occurring radiation will enter it instantly and end up in a feedback loop, instantly getting strong enough to destroy the wormhole. So because of feedback radiation, time travel is not possible this way.

2. A far simpler proof is that to this day (To the best of our knowledge), we have not yet been visited by time travelers. Some scientists, including Stephen Hawking, have set up meeting events for time travelers and revealed that these meetings happened afterwards, this way only time travelers would know to attend it, but none have. Since mankind has a very long time left to live (I hope), we should hypothetically have time travelers springing up all over the place, yet they don't.

3. Another reason that disproves that we will ever reverse time travel is because of the Temporal Paradox. An example of the Temporal Paradox is if I were to build A time machine, and shoot myself 1 year in the past so I couldn't make the time machine. This is a simple logically fallacy in the concept of reverse time travel.



A wormhole, also known as an "Einstein-Rosen bridge", was suggested by Albert Einstein and Nathan Rosen in 1935. Basically, it's the concept of a hypothetical topological feature that would connect two separate points in spacetime. The suggestion is a popular feature in science fiction work, for example in the movie of Interstellar.

Kip Thorne, one of the most well known theoretical physicists of California Institute of Technology, suggested back in the 80s that a wormhole theoretically could be used for time travel in either direction, to the past or to the future. In his theory, he believes it is possible by accelerating one mouth of the wormhole to near-light speed and then reverse it back to its original position. Meanwhile, the other mouth would remain stationary. The result would be that the moving mouth would age less slowly than the stationary mouth thanks to the effect of time dilation, more on this in a second.



Cosmic strings is a theory of stringlike objects smaller than atoms believed to be have been formed in the early universe. More detailed, they are believed to be 1-dimensional topological defects in the fabric of spacetime. The idea of these was suggested by J. Richard Gott, professor of astrophysical sciences at Princeton University.

Some scientists believe reverse time travel could be possible through the courtesy of maneuvering two of these strings closely together, or one into a black hole, it would be possible to create a whole array of "closed time-like curves". It is then believed that if we would fire two infinitely long cosmic strings past each other at very high speeds, we could fly a ship around them in a carefully calculated figure eight. In theory, one would be able to emerge anywhere, anytime.



This is one of the most popular argument against reverse time travel, and a variant of the Fermi paradox, a paradox describing the contradiction between the high estimated numbers of the existence of extraterrestrial civilizations versus the lack of evidence of such. Even scientists as Stephen Hawking has presented the seemingly absence of future time travelers as a compelling argument that reverse time travel never could be achievable.

But, how much chaos wouldn't future time travelers cause if they would come to this time and show us compelling evidence that they are from the future (such as advanced inventions)? Would today's humans not react at all of having their worldview changed that dramatically? Such a chaos would also have an impact of the time which the future time traveler originates from (Butterfly effect). And wouldn't it be quite a paradox if a human civilization is smart enough to create time travel, but yet be clumsy enough to cause something like this? The so-called Flynn effect is showing us how humanity is scoring better and better on IQ tests every year now. So given our world will thrive like it is doing now, why would a human civilization from 6 853 163 AD not think of this risk? Such an intelligent civilization would probably had avoided this risk by for example having some kind of invisibility when being a tourist in this time.

Another way to refute this argument would be by suggesting that humans could see into our time period without being here physically, through the courtesy of some kind of what we today would call a computer program for example.

One abstract mind game one could also be playing with would be that we in 2016 perhaps are the "furthest" in to the future, thus making no one at all ahead of our time.
Debate Round No. 2


1. I previously disproved that wormholes cant be used for time travel due to feedback radiation

2. Quantum strings (I call them that because it sounds cooler!) are a unfeasible way of reverse time travel. As state by J.Richard Gott himself, in order to travel back one year it would require a loop of string that yielded half the mass-energy of an entire galaxy, imagine splitting half the atoms in a galaxy to time travel. Additionally, you could go back no further than the point at which the hypothetical time machine was created.

3. I mostly agree with this point, however it proves that there is no evidence present in modern society of reverse time travelers existing.

3b: "Another way to refute this argument would be by suggesting that humans could see into our time period without being here physically, through the courtesy of some kind of what we today would call a computer program for example." That wouldn't really be reverse time travel, but it is an interesting concept nonetheless

3c:"One abstract mind game one could also be playing with would be that we in 2016 perhaps are the "furthest" in to the future, thus making no one at all ahead of our time." That is illogical, because the people of the future will exist and therefore can time travel back to visit us.


1. This argument is true, but a barrier for making radiation not entering the wormhole could theoretically be invented. Hence, this argument only tells that it's of today impossible to travel through a wormhole.

2. How much that would be needed for such a time travel to work is irrelevant. We are talking about possibility and not about what needs to be done and what consequences that could have. Con shows how the time travel is possible. It is also true that we couldn't go further back than to the point the time machine was created, but that is not an argument against reverse time travel, only an argument against reverse time travel to whichever time point.

One could also be playing with the thought that pre-historical extraterrestrial civilizations made a loop of string possible to use to travel back to their time, which theoretically could be billions of years far back in time.

3. Evidence of absence is necessarily not absence of evidence.

3b. It wouldn't be travel per definition, but a substitute to it.

3c. It was a little mind game I wasn't thinking too much about. However, the "time travelers are by choice invisible" argument is to me the most compelling one to refute the "there haven't been people from the future here" argument.

Con also shows the Temporal Paradox in round 1. Which is neither an argument against reverse time travel, since he is already implying that reverse time travel already has happened in his mind game where he is time travelling only to shoot his former self. Hence, consequences of such actions in a hypothetical time where reverse time travel is possible are off topic from this debate.
Debate Round No. 3


1. No barrier can be made, especially considering there is an entrance and exit to a wormhole, wherever the wormhole goes, you cant prevent radiation from entering on either side.

2. Yes, but because of the immense amount of material required it could never be used for reverse time travel, its is completely hypothetical.

3. Just shows that there are no known time travelers.

3b. So not time travel at all

3c. Seems unlikely that every single time traveller would remain invisible, mistakes happen.

4. It is an argument against time travel, it proves that time travel cannot happen without paradoxes which proves that reverse time travel is illogical.


1. Technically, in a vast future, something could be created to repel radiation somehow. It doesn't need to be a wall. You might think right now this is impossible, but then if you would tell someone from the Middle Ages about cars, they wouldn't believe that was possible either.

2. In a vast future, one galaxy broken down perhaps wouldn't matter if we have 10000s of galaxies colonized. And this is a little moot point anyway since it is not about the possibility of reverse time travel, only what it would require.

3. I refer to my previous explanations.

3b) Logically, they would have time travel possible, but choose this way instead.

3c) People in a further future would maybe be that perfect that they don't do mistakes. And even if a mistake would happen, they could repair the mistake somehow, like making people forget that they witnessed what they just witnessed.

4. You can time travel to the past without having to do such things, and the problem would be solved. I think people in the future would have a quite good way of repairing it if such a thing would happen too.
Debate Round No. 4
3 comments have been posted on this debate. Showing 1 through 3 records.
Posted by skipsaweirdo 8 months ago
Never seen more confusing cause and effect bulls. hit@t and unsubstantiated assertions and equivocation fallacies all in one paragraph dharge. Where do get your ridiculous ideas of how things are defined and what they are? Comic books or logically inept religious zealots who worship their god might think time is what you say. Those of us who are critical thinkers know time is nothing more than what some bronze aged idiot came up with because he saw the circular movement of a shadow cast by an obelisk.
Your reasoning
Shadow move in circle.
Man make sundial
Sundial shadow move in circle too
Man made clocks
Clock hands move in circle
Therefore time is some special thing or dimension we might be able to travel around,through, or from one point to another....uggggg, me club woman on head and steal her rock collection to build shadow tracker.....
Posted by Peepette 8 months ago
RFD: The debate is primarily on three issues, worm holes, quantum strings, and time travelers. Wormholes: CON, due to feedback radiation wormhole travel is not possible; radiation gets strong enough to destroy the worm hole. PRO rebuts a device could be made to repel radiation. The feedback issue is not addressed by PRO but, the point is dropped by CON. Quantum Strings: CON contends the vast amount of energy needed makes time travel impossible. PRO rebuts the amount of energy needed is not the issue, only what is required to make time travel possible. Time Travelers: CON states no evidence of them exists. PRO rebuts proof is not a factor due time travel humans are so advanced they would have the means to make themselves invisible; a point CON concedes. The paradox issue of reverse time travel also is rebutted by PRO due again to the advanced nature of the travelers. PRO used sources but they did not have weight toward his arguments. S&P: both PRO & CON exhibited command of the language. Both sides showed congeniality throughout the debate.
Posted by dhardage 8 months ago
This is an interesting debate and both sides have presented some compelling arguments. The fact is we are all travelling in time, all going in the same direction at close to the same speed. That changes a little for astronauts and equipment sent into space since they are no longer subject to gravitational effects on their relative time but are subject to velocity affects. From this we know that time and space are inextricably intertwined. I don't believe we will ever develop time travel into the unless it can be linked back to space as well. If you jump directly back in time one year without any spatial shift, you will find yourself in deep space since the earth, the solar system, and the Milky Way are all moving at incredible speeds. While time travel may be theoretically possible I don't think it will ever be feasible or developed in any useable way. Just my thoughts on the subject.
1 votes has been placed for this debate.
Vote Placed by Peepette 8 months ago
Who won the debate:-Vote Checkmark
Reasons for voting decision: RFD in comments