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Does the lack of time travellers now prove time travel will never be possible?

As the title says.

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Not necessarily.

It may simply be a case of us not understanding or being aware of time travelers. It's difficult because we don't actually know how time travel would work physically for the traveler, or what humanity would look like by such a point.

The lack of the stereotypical time traveler would indicate that time travel in the form of hopping into a machine and being physically transported back, is impossible.

Also, to put things in perspective, if you take a square mile somewhere on the planet and check for planes, it is quite conceivable that no planes will fly above that square mile. This does not mean planes do not exist.
Reply 2
No. It just means they're really really good at blending in with the local population!


Posted from TSR Mobile
Only if you assume that time has a single linear pathway. If a new multiverse is spawned when a traveller goes back in time then they wouldn't be interfering with our world in the first place so we wouldn't expect to have seen any time travellers yet.
I'm sure time travellers would attempt to remain as clandestine as possible, in order to avoid any time paradoxes etc. You know the gist, if he accidentally kills someone it could have a drastic effect on his life and so on.

Therefore we are probably not aware of time travellers and they may even be high up in society.
Original post by Stegosaurus99
I'm sure time travellers would attempt to remain as clandestine as possible, in order to avoid any time paradoxes etc. You know the gist, if he accidentally kills someone it could have a drastic effect on his life and so on.

Therefore we are probably not aware of time travellers and they may even be high up in society.


I think if Time Travelers did come back, they would have a fundamentally different view of time than we do now. I feel that they would be unconcerned about potential time paradoxes, because they would understand such a thing is impossible.
Reply 6
I was watching Back to the Future while drunk when I asked this, sorry if it's a strange question.

Original post by Farm_Ecology
Not necessarily.

It may simply be a case of us not understanding or being aware of time travelers. It's difficult because we don't actually know how time travel would work physically for the traveler, or what humanity would look like by such a point.

The lack of the stereotypical time traveler would indicate that time travel in the form of hopping into a machine and being physically transported back, is impossible.

Also, to put things in perspective, if you take a square mile somewhere on the planet and check for planes, it is quite conceivable that no planes will fly above that square mile. This does not mean planes do not exist.

Well, I guess I meant specifically time travel that allows one to interact with the past.

Your plane analogy isn't quite fitting. Time travelers wouldn't just pass us by, they would want to watch us or interact with us.

Original post by Plagioclase
Only if you assume that time has a single linear pathway. If a new multiverse is spawned when a traveller goes back in time then they wouldn't be interfering with our world in the first place so we wouldn't expect to have seen any time travellers yet.
true.


What does your first question mean? I don't understand it.As for the second question, where else should I put this question? I wanted to ask it and didn't know the right forum. Mods can move it to science if they like lol.
Reply 7
Time does not exist as somewhere to go. There is just matter and energy doing stuff. We think there was a past because we have memories. Remembering stuff is essential for learning and learning is essential for being a better predator or hunter/gatherer. We remember where the fruit trees were or where the mammoths go to drink and use that data to go there again. We even plan and decide to go there tomorrow and so we have invented the concept of 'future time'. There is just 'predicted future state'.

The whole timeline is only in our heads. There is only now. There is no past to go back to. There is no future to return from. No was, no will be. There is only 'is'.

Time travel is not possible.

For it to be possible, all the energy and matter in the universe would have to be put back how it 'was' in an earlier state. Do that (which we cannot) and there is nowhere for the time traveller to be - that space is already taken up by matter and photons. Just moving that matter and those photons changes the state of the universe; it would be in a different state, you would be in a different time, a time that never existed.

Time travel is just a fantasy made up in our heads as a consequence of thinking yesterday still exists somewhere because we remember it. It's gone. For ever.

Edit: Has this been moved out of philosophy? It's a classic philosophy question.
(edited 8 years ago)
No, because according to physics, you can't go back in time, only forward, if you could generate the power. Hence you would not be getting visitors from the future.
How do you know there are no time travellers? Perhaps yesterday when you woke up 11th September 2001 was just a normal day but since someone changed that day (maliciously or otherwise) today you remember it as you do now. If someone went back and killed your grandfather (assuming universe where this was possible or where it doesn't create parallel universe), you'd cease to exist and no one would notice because no one would actually remember you existing. Thing with time travel is, if you change the past you change the present such that it is consistent with the past so you'll never know the difference.
Time travel to the past isn't possible however it is theoretically possible to travel into the future, but then of course there is no way back.
Reply 12
Original post by swanderfeild
How do you know there are no time travellers? Perhaps yesterday when you woke up 11th September 2001 was just a normal day but since someone changed that day (maliciously or otherwise) today you remember it as you do now. If someone went back and killed your grandfather (assuming universe where this was possible or where it doesn't create parallel universe), you'd cease to exist and no one would notice because no one would actually remember you existing. Thing with time travel is, if you change the past you change the present such that it is consistent with the past so you'll never know the difference.

Oooh. Love it. If the past is changed, we wouldn't know.

I don't think you understood the question. Like, at all. Your example with computers makes no sense... once computers were invented, history wasn't suddenly changed so that computers were around hundreds of years ago. I'm talking about TIME TRAVEL.
Original post by MathsAstronomy12


Thanks for this link! :smile:
Reply 14
<sigh> OK.

"Does the lack of time travellers now prove time travel will never be possible?"
No, it's because time travel is not meaningful.
Do explain
Reply 16
Sorry, no.

I think it is a very good and insightful question warranting lots of debate. My undefended and non-peer-reviewed view is that time travel is itself impossible.
Original post by MathsAstronomy12
Do explain

We are all travelling forward in time at one second per second; if you are moving you are travelling slightly less than one second per second relative to rest frame with respect to earth (hence the twin "paradox").
So time travel to future is not only possible but a reality since existence of any organisms; travel to past requires faster than light travel so is abit more tricky.
(edited 8 years ago)
Original post by swanderfeild
We are all travelling forward in time at one second per second; if you are moving you are travelling slightly less than one second per second relative to rest frame with respect to earth (hence the twin "paradox":wink:.
So time travel to future is not only possible but a reality since existence of any organisms; travel to past requires faster than light travel so is abit more tricky.


You are right but on Earth the effect (time dilation) is so tiny that it can be neglected. If you're moving at relativistic speeds (near light) or are in an ultrastrong gravitational field, thats a whole different story.
A strong gravitational field will slow your time down relative to others who are not in the gravitational field. You are technically correct but the effect is negligible on earth, but still cool i know!

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