ChickenOfDoom
2008-11-27, 09:20
I've always thought any fictional depictions of time travel were ridiculous.
Say you had a time machine. You move the time machine into place. Five minutes later, you use the time machine to go six minutes back in time. Where, in the previous iteration of the universe, there was only empty space where the time machine was, there is now you. This is the second recursion; the first running of the algorithm (a specific space of time in the universe) was when you had not traveled back in time at all. Assume that reality, as you actually would experience it, is the final iteration of these recursions. Assume that, instead of creating some sort of bullshit copout alternate universes, time travel actually overwrites the past and your memories of what things were like before you changed them are illusionary. If you kill your past self and destroy the time machine, you don't fade away, because you have inserted yourself into reality; you are there, you don't need to have come from anywhere. The time machine works like this:
(Universe defined as a time and physical state)
(for the sake of simplifying all this assume that you are the only one who can go back in time and there is only one time to go from and only one possible time you can go to; 5 minutes before the go back time)
public Universe timeTravel(Person you, Universe destination)
{
Universe newPast=new Universe(you+destination)
Universe travelTime=newPast+5Minutes
if(travelTime.timeTravelNow)
{
return timeTravel(travelTime.pastYou,newPast)
}
else
{
return travelTime
}
}
Say that, in the hypothetical second iteration where time travel has only occurred once, you come with an agreement with yourself. Future you will move out of the way so that you can move your time machine into position.
You were stupid and forgot future you was in the exact same place as the time machine is now, five minutes ago. This time, instead of seeing one copy of himself where the time machine is supposed to go, past you sees two copies of himself displaced amongst themselves and bleeding all over the place. Since the brains were in similar positions they aren't really alive.
For the sake of continuing the chain, let's say that you aren't perturbed by this and decide to simply put the time machine a few feet to the right of the mess. You go back.
Now there's the conjoined people, future you, and past you. You explain to past you that there's nothing to worry about and to continue the experiment. Past you waits and goes back in time again. There is now the blob and three of you standing there. You realize what's been happening and the three of you decide to put a stop to it; you destroy the time machine. The algorithm has reached its base case. Time travel never happened (happened being something in the past after all); your intent and ability to time travel caused the universe to bring about conditions that would prevent you from doing so.
Of course that's assuming that time travel is a function that always returns. You might be able to have an infinite loop.
Assume that you're completely crazy and you didn't have any intention of doing anything about the growing clone army. You continue going back in time, there continues to be more of you.
Can this continue forever? To address logistical problems, assume that your time machine could also move you anywhere in space at the same time. You go to every square foot of the earth, and take with you a communications device to transmit back which space you have occupied, which is used to know where not to go next time. You start filling other parts of the universe. You have infinite space, after all. Assume also that your time machine can be programmed to send you arbitrarily long distances. The universe continues to become more and more full, the timeline being successively rewritten to put more of you into it. The number of your clones approaches infinity, and has no way of stopping; once you started moving yourself outside the earth, you ceased to be influenced by future you; you, and the earth, are now identical to the previous iteration and will continue making the same decisions, save for the communicator, which is just a number.
Actually, that's something I'm not sure about; is it possible to express arbitrarily high numbers? If it's not this doesn't work and the algorithm would reach a base case when you could no longer express a new location to send yourself to.
Anyways, assuming you can, this is going to be an infinite loop. Reality will be constantly altered and can no longer be expressed linearly. Since I proposed that the end iteration be considered to overwrite everything else, you can't say that there is branching. The result is undefined; the universe as we know it no longer exists.
So basically, time travel isn't possible. The universe either structures itself so that you don't go back in time (through the mechanics of time travel themselves), or is undefined.
Any thoughts? Anywhere you think I went wrong with this? Anyone think time travel or time itself wouldn't work like that?
Say you had a time machine. You move the time machine into place. Five minutes later, you use the time machine to go six minutes back in time. Where, in the previous iteration of the universe, there was only empty space where the time machine was, there is now you. This is the second recursion; the first running of the algorithm (a specific space of time in the universe) was when you had not traveled back in time at all. Assume that reality, as you actually would experience it, is the final iteration of these recursions. Assume that, instead of creating some sort of bullshit copout alternate universes, time travel actually overwrites the past and your memories of what things were like before you changed them are illusionary. If you kill your past self and destroy the time machine, you don't fade away, because you have inserted yourself into reality; you are there, you don't need to have come from anywhere. The time machine works like this:
(Universe defined as a time and physical state)
(for the sake of simplifying all this assume that you are the only one who can go back in time and there is only one time to go from and only one possible time you can go to; 5 minutes before the go back time)
public Universe timeTravel(Person you, Universe destination)
{
Universe newPast=new Universe(you+destination)
Universe travelTime=newPast+5Minutes
if(travelTime.timeTravelNow)
{
return timeTravel(travelTime.pastYou,newPast)
}
else
{
return travelTime
}
}
Say that, in the hypothetical second iteration where time travel has only occurred once, you come with an agreement with yourself. Future you will move out of the way so that you can move your time machine into position.
You were stupid and forgot future you was in the exact same place as the time machine is now, five minutes ago. This time, instead of seeing one copy of himself where the time machine is supposed to go, past you sees two copies of himself displaced amongst themselves and bleeding all over the place. Since the brains were in similar positions they aren't really alive.
For the sake of continuing the chain, let's say that you aren't perturbed by this and decide to simply put the time machine a few feet to the right of the mess. You go back.
Now there's the conjoined people, future you, and past you. You explain to past you that there's nothing to worry about and to continue the experiment. Past you waits and goes back in time again. There is now the blob and three of you standing there. You realize what's been happening and the three of you decide to put a stop to it; you destroy the time machine. The algorithm has reached its base case. Time travel never happened (happened being something in the past after all); your intent and ability to time travel caused the universe to bring about conditions that would prevent you from doing so.
Of course that's assuming that time travel is a function that always returns. You might be able to have an infinite loop.
Assume that you're completely crazy and you didn't have any intention of doing anything about the growing clone army. You continue going back in time, there continues to be more of you.
Can this continue forever? To address logistical problems, assume that your time machine could also move you anywhere in space at the same time. You go to every square foot of the earth, and take with you a communications device to transmit back which space you have occupied, which is used to know where not to go next time. You start filling other parts of the universe. You have infinite space, after all. Assume also that your time machine can be programmed to send you arbitrarily long distances. The universe continues to become more and more full, the timeline being successively rewritten to put more of you into it. The number of your clones approaches infinity, and has no way of stopping; once you started moving yourself outside the earth, you ceased to be influenced by future you; you, and the earth, are now identical to the previous iteration and will continue making the same decisions, save for the communicator, which is just a number.
Actually, that's something I'm not sure about; is it possible to express arbitrarily high numbers? If it's not this doesn't work and the algorithm would reach a base case when you could no longer express a new location to send yourself to.
Anyways, assuming you can, this is going to be an infinite loop. Reality will be constantly altered and can no longer be expressed linearly. Since I proposed that the end iteration be considered to overwrite everything else, you can't say that there is branching. The result is undefined; the universe as we know it no longer exists.
So basically, time travel isn't possible. The universe either structures itself so that you don't go back in time (through the mechanics of time travel themselves), or is undefined.
Any thoughts? Anywhere you think I went wrong with this? Anyone think time travel or time itself wouldn't work like that?