Assuming time travel exists: is it possible to alter the past?
If an event occurs, and you decide to travel back in time to change/prevent that event: It has no longer occurred in the way that caused you to want to change it; thus you never travel back to change it, and it does occur…
Perhaps. Unless you consider multiverse theory: The idea that the act of traveling to the past splits the timeline into two realities. One containing the original (to your perspective) timeline with the event(s) that caused you to travel back, and a second where you’ve arrived in the past to alter those events and the results there of.
Not sure I believe it, but it’s a theory none the less.
Or maybe it’s only possible to travel forward in time. Closer to our current understanding of the universe.
The multiverse conception of time travel is nice and fine for fiction, but in reality, if you think about what such a time machine would have to do, it would have to create an entire new universe, with all precise details exactly in place, and it would have to have a lower entropy than your origin reality. Good luck building such a machine
I was playing with this recently. Suppose you are playing rock, paper, scissors with yourself from a few minutes into the future. Your future self “remembers” what you will play and so as long as you play normally, future self always wins. But change the rules a bit and play where future you goes first.
In a normal game, you should always win because you clearly see how future you played, but future you played to counter what future you remembers present you playing…
E.g. future you remembers playing paper, and so plays scissors. You see scissors and go go play rock, but that should be impossible because future you doesn’t remember playing rock.
The weird thing to me is not that the second scenario (where future you goes first fails) but that playing normally (both going at the same time) works. I think the paradox emerges when future knowledge is introduced to the past. In the normal game, future you does not expose future knowledge until the exact moment you play and cause that knowledge to exist in your present, but in the altered game, the introduction of future knowledge creates a feedback loop.
Of course the game isn’t needed. Simply seeing future you conveys the fact that you exist in the future. Should you, for example (and please don’t do this) see near future you then stab your arm with scissors, you will miss or be stopped because future you does not have a wounded arm.
I wonder what happens if future you’s arm is out of sight. would you be able to stab your arm then only for future you to then reveal a wounded arm?
Assuming time travel exists: is it possible to alter the past?
If an event occurs, and you decide to travel back in time to change/prevent that event: It has no longer occurred in the way that caused you to want to change it; thus you never travel back to change it, and it does occur…
The Grandfather Paradox, I’m partial to that one as well.
I think that just shows that time travel doesn’t exist.
Perhaps. Unless you consider multiverse theory: The idea that the act of traveling to the past splits the timeline into two realities. One containing the original (to your perspective) timeline with the event(s) that caused you to travel back, and a second where you’ve arrived in the past to alter those events and the results there of.
Not sure I believe it, but it’s a theory none the less.
Or maybe it’s only possible to travel forward in time. Closer to our current understanding of the universe.
The multiverse conception of time travel is nice and fine for fiction, but in reality, if you think about what such a time machine would have to do, it would have to create an entire new universe, with all precise details exactly in place, and it would have to have a lower entropy than your origin reality. Good luck building such a machine
I was playing with this recently. Suppose you are playing rock, paper, scissors with yourself from a few minutes into the future. Your future self “remembers” what you will play and so as long as you play normally, future self always wins. But change the rules a bit and play where future you goes first.
In a normal game, you should always win because you clearly see how future you played, but future you played to counter what future you remembers present you playing…
E.g. future you remembers playing paper, and so plays scissors. You see scissors and go go play rock, but that should be impossible because future you doesn’t remember playing rock.
The weird thing to me is not that the second scenario (where future you goes first fails) but that playing normally (both going at the same time) works. I think the paradox emerges when future knowledge is introduced to the past. In the normal game, future you does not expose future knowledge until the exact moment you play and cause that knowledge to exist in your present, but in the altered game, the introduction of future knowledge creates a feedback loop.
Of course the game isn’t needed. Simply seeing future you conveys the fact that you exist in the future. Should you, for example (and please don’t do this) see near future you then stab your arm with scissors, you will miss or be stopped because future you does not have a wounded arm.
I wonder what happens if future you’s arm is out of sight. would you be able to stab your arm then only for future you to then reveal a wounded arm?