When we travel back in time, does it change the future if you don’t touch anything but travel back?
36-40, F
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room101 · 51-55, M
Somebody, or maybe you, invented a mechanism which allowed you to travel back in time. Which means that [i]events had to play out exactly as they did for that mechanism to exist.[/i]
You use that mechanism to go back in time. Your mere presence constitutes physically touching that point in time (as explained by [@PhpPheonix]. However, your presence in that previous point in time cannot change your future because, if it did, the time travel mechanism would not have been invented.
Because..............[i]events had to play out exactly as they did for that mechanism to exist.[/i]
You use that mechanism to go back in time. Your mere presence constitutes physically touching that point in time (as explained by [@PhpPheonix]. However, your presence in that previous point in time cannot change your future because, if it did, the time travel mechanism would not have been invented.
Because..............[i]events had to play out exactly as they did for that mechanism to exist.[/i]
NerdyPotato · M
@room101 But once you develop a time machine and take it to the past, you pretty much create a new timeline. In that timeline is it not necessary to for everything to happen the exact same way, because the time machine now existed since 1800 or whatever year you travelled to.
room101 · 51-55, M
@NerdyPotato Depends if we believe that there is one unchanging time-line or if there are many or if a new time-line has been created by us travelling back in time.
If there is only one time-line then that time machine did indeed exist in 1800 (or whenever we travelled back to) but it was not of that time. It was used to take us there and to bring us back to our own point in time.
If there is only one time-line then that time machine did indeed exist in 1800 (or whenever we travelled back to) but it was not of that time. It was used to take us there and to bring us back to our own point in time.
NerdyPotato · M
@room101 Time travel into the past is simply not possible in a single unchanging timeline. By traveling back in time you change the past by definition. The change can be "saved" as a new alternative timeline or overwriting the original, but inserting yourself in the past is already a change and thus impossible if time were unchanging.
room101 · 51-55, M
@NerdyPotato But surely an unchanging time-line would already incorporate that visit to the past. It would be part of that same fabric of time would it not?
NerdyPotato · M
@room101 That's an interesting theory, but that means time isn't straight-up linear. The only way for the visit to be written into history is if history was written after the machine was created in the future. So either we're experiencing time in reverse or the invention and visit actually happened simultaneously.
room101 · 51-55, M
@NerdyPotato Until relatively recently we believed that time is indeed "straight-up linear". Now, we are investigating theories which hinge on a multi-dimensional perspective of time.
If time is linear then it is, by definition, unchanging. Our time traveller went back in time but did nothing which affected the technology of that time. Hence, the time machine he used was still waiting to be invented. And yes, that visit would have been written into history. But probably as a sci-fi anecdote.
If time is linear then it is, by definition, unchanging. Our time traveller went back in time but did nothing which affected the technology of that time. Hence, the time machine he used was still waiting to be invented. And yes, that visit would have been written into history. But probably as a sci-fi anecdote.