The reason I don't think Time Travel is possible.

[Jersovic]

In order to believe that time travel is possible, you first have to believe that time does not exist. If this is the case then the future has already happened. Why then, haven't we been visited by future humans?

Does anyone have any explanation for why this hasn't happened?

[Temp name]

because they made a law against going back in time before it was invented?

or *puts on tinfoil hat* you're the only person actually from this time, and everyone else is from the future, and wants to see how long it takes you to figure out?

[Deleted]

Maybe they do not allow dumbasses that will contaminate the timeline to time travel.

[HungryHippo]

In order to believe that time travel is possible, you first have to believe that time does not exist. If this is the case then the future has already happened. Why then, haven't we been visited by future humans?

Does anyone have any explanation for why this hasn't happened?

You can only go forward in time not backward, sorta like that furturama episode

[Theodon]

If we were visited by future humans, and we, the population at large, knew about it, it would forever change the future and the future the future people came from would no longer exist, therefore they could not have come back in to the past to visit us.

[Kalmakk]

Either because time travel isn't possible, or, more likely, humanity destroys itself before the technology is discovered.

[Deleted]

Who wants a bunch of damn goobacks here anyway? Taking our jobs...

[isuridedes]

In order to believe that time travel is possible, you first have to believe that time does not exist. If this is the case then the future has already happened. Why then, haven't we been visited by future humans? Does anyone have any explanation for why this hasn't happened?

Shouldn't it be more along the lines of "In order to believe that time travel is possible, you first have to believe that time does not behave as we currently understand it."

I don't really think that A necessitates B in your argument in either case.

And really... what benefit would there be in future humans time traveling and announcing "Hey Past; we're from the future!". Are they going to tell us to change our ways for the better of mankind? Will we listen? Nah - we're going to put them in crazy cells.

[Kalmakk]

OP is missing a fairly crucial point actually, that being that Black Holes do actually generate their own "time travel" singularities. They have so much mass and gravitational pull that they actually stop, and infinitely speed up time, at the same time.

Time manipulation is very much possible, it's just astronomically unlikely that humans will ever harness it at will.

[Deleted]

Who wants a bunch of damn goobacks here anyway? Taking our jobs...

They tuk ur juuubs!

[Davisdoesdallas]

In order to believe that time travel is possible, you first have to believe that time does not exist. If this is the case then the future has already happened. Why then, haven't we been visited by future humans?

Does anyone have any explanation for why this hasn't happened?

Alright, so I normally don't say this because I love weed.



QUIT SMOKING POT!

For reals.

[Kalmakk]

There's also the possibility that the technology required to manipulate atomic structures through time is beyond the technology to travel between universes, and by the time time travel is invented they already realised how fucked up that would make our course of history, so they only travel to different universes.

[Banzhe]

In order to believe that time travel is possible, you first have to believe that time does not exist.

Maybe it has to do with time not moving at all, but it's space that bends thereby getting the false tag of "time travel".., you can't move backwards, simple as.

Sure some genius will bring in a Hollywood film like Time Cop now, but he isn't travelling back in time, he's travelling to an alternate dimension which I'm sure will be possible one day, just not with identical people.

[Deleted]

Time travel by the definition of travelling days/months/years into the future does not exist.
Time travel by the definition of moving faster in a set amount of time as opposed to moving in normal speed exists.

Time travel is just another thing weak people dream about to escape real life. Sort of like people believing in religion. But thats a whole other topic

[mini98]

In order to believe that time travel is possible, you first have to believe that time does not exist. If this is the case then the future has already happened. Why then, haven't we been visited by future humans?

Does anyone have any explanation for why this hasn't happened?

Time doesn't exist, neither does past, present or future. Time is just a word humans like to place for to try to measure life and as such has no meaning beyond human minds therefore anyone who doesn't exist in time is correct in my opinion.
And no it does not mean the future has already happened, time travel can mean the past as well. And it is possible to go into the past if you go fast enough.

[Davisdoesdallas]

Time doesn't exist, neither does past, present or future. Time is just a word humans like to place for to try to measure life and as such has no meaning beyond human minds therefore anyone who doesn't exist in time is correct in my opinion.
And no it does not mean the future has already happened, time travel can mean the past as well. And it is possible to go into the past if you go fast enough.

oh raelly?


cause last time I took a theoretical physics class, moving backwards = not possible. Time is related to the place of the universe. If the universe expands(as it does) than you can not go backwards to that place in the universe you once were. You would literally have to suck the universe inward..

[Deleted]

Time doesn't exist, neither does past, present or future. Time is just a word humans like to place for to try to measure life and as such has no meaning beyond human minds therefore anyone who doesn't exist in time is correct in my opinion.
And no it does not mean the future has already happened, time travel can mean the past as well. And it is possible to go into the past if you go fast enough.

You mean future, if you're travelling near light-speed you actually move through time faster, and time does exist, it exists as space-time, and it moves slower under the effects of gravity, which is why my first point is true.

[Spl4sh3r]

If we were visited by future humans, and we, the population at large, knew about it, it would forever change the future and the future the future people came from would no longer exist, therefore they could not have come back in to the past to visit us.

That's only if you assume there is only one timeline we can go through. If there is an infinite amounts of universes for all our actions, wouldn't there be one universe that branch of when we go back in time? So their timeline would still exist where they go back in time, even if it changes our timeline when we change the future from knowing that there are people from the future at us?

[Deleted]

Well, everybody knows, that Einstein was a clever guy and far ahead in the future in comparison to his contemporaries.

None of his laws was disputed by now and I guess that's because they are "right".

His laws show, that you can travel in time, if you move faster than light. But no human or even scientist could prove a motion, that was faster than light by now. Not even a single electron could be accelerated to that speed (If you round up, maybe the exact speed of light, but technically it's just not possible there will always be some incredible small piece of speed missing.) How are we supposed to move things even faster, that have unimaginable more mass.

Then the worm hole thing. Even if you could travel through time, using them, you couldn't go through a worm hole in a whole :-)
All your atoms may come through, but nowhere near together :-P. You would be evaporated by the force. Not to mention, that each worm hole is like thousands of lightyears away from earth. So it is kind of impracticable, (again) if it is possible at all to travel through time, to use them.

Though it's interesting, that for example cosmonauts, who stay on the ISS (for max. 6 months as it is not really healthy to stay longer; moving constantly with ca. 7800 m/s; c (speed of light)= ca. 300.000.000 m/s!!) are a few nanoseconds younger when they come back to earth ;-). The faster you are, the slower time goes by (at least from your standpoint in comparison to a person, who is "slower"). If you would move with the exact speed of light you would theoritically stop aging. But for example the ISS is one of the fastest moving manned vehicles and reaches only 0,0028% of the speed of light. So you can imagine that it's not likely, that we will ever even come near the speed of light.

(I hope there are no miscalculations made by me. If that is the case, please correct me)

[Sayl]

In order to believe that time travel is possible, you first have to believe that time does not exist. If this is the case then the future has already happened. Why then, haven't we been visited by future humans?

Does anyone have any explanation for why this hasn't happened?

If you have an hour to kill, Sean Carroll puts the hammer down. Enjoy.