Time travel hasn't been invented yet. Which sucks:< Who wouldn't want to change their past mistakes. What if it has been invented in the future and people do travel back. However, every time they change something, however minute, an alternate reality is created and the one that we exist in isn't changed. Could this be why, we haven't been visited by time travelers from the future?

P.S. I am asking this because of this Article here. And yes, I do know that by the rules of physics, time travel backwards isn't theoretically possible.

  • $\begingroup$ pretty sure this is a duplicate, but I am too lazy to find it $\endgroup$
    – TrEs-2b
    Aug 28, 2016 at 10:56
  • 6
  • $\begingroup$ Hello and welcome to Worldbuilding. Unfortunately I have to vote to close your question because it is not actually about building a world, as detailed in these nifty guidelines: worldbuilding.stackexchange.com/help/how-to-ask Please read through those, and you are most welcome with any other question you may have, on building worlds. I would also suggest to post this particular question in the Physics or Philosophy Stack Exchange, because those are more appropriate areas for this kind of questions. :) $\endgroup$
    – MichaelK
    Aug 28, 2016 at 11:02
  • $\begingroup$ Since this is WorldBuilding, and there are no internal logical holes in your question, it seems like you've answered your own question. It may be useful for you to think through the implications of that and see if you have a question that is more in the bounds of WorldBuilding. "If time travel only makes branching timelines then what's the point" isn't right either... But if you put a little thought into it I'm sure you could think of something that we could help you with. Welcome to the site! $\endgroup$
    – AndyD273
    Aug 28, 2016 at 12:03
  • $\begingroup$ This is under the assumption that we are on the first branch. If we aren't then the could be why we have been visited by time travelers from the future, but we don't believe them. $\endgroup$
    – Theraot
    Aug 28, 2016 at 12:29

3 Answers 3


There is another possibility, Niven's Law of Time Travel

If the universe of discourse permits the possibility of time travel and of changing the past, then no time machine will be invented in that universe.

Every trip to the past changes the timeline. "Sooner" or "later" some bozo will make a change in the past which will result in time travel not being invented. That timeline will be stable, since no one goes back to alter the past.

  • $\begingroup$ interesting point! $\endgroup$ Aug 28, 2016 at 13:13

Hypothetically if time travel worked the way you described, we would never know that time travel existed. Every time someone from another time arrived in our time a new branched history would be created and our present would remain unchanged.

But that's basically what you said in your question any way. This is somewhat tautological.

There are,of course, many other objections to time travel such that if it existed we would never know about it. Which is, probably, a good thing.


Time travel in the future is already possible... well electricity and photons do move straight in the future faster than anything

and we humans travel in the future for each second passing but at a slower rate.

However time travel isn't possible,as already pointed out by other users when traveling back in time you automatically cancel the reason you traveled back in time in the first place.

However there are 2 ways in which you could give the illusion of traveling back in time.

1)When traveling back in time you don't actually really go in the past but create a clone of your universe with a different time lane, however it doesn't have any whatsoever effect on the original universe.

So if you go back in time to save the life of someone you will not save them, they will remain dead in your universe but you will create a clone of them in another universe.

2)Dying, being dead could be the philosophical equivalent of traveling back in time. As you didn't exist before your birth you will stop to exist after your death, you could metaphorically consider dying as returning back to your past black dark and void nothingness-


Not the answer you're looking for? Browse other questions tagged .