Time traveler puzzle

[questionposter]

A time traveler travels exactly 3 seconds to into the past from where he was standing, however when he arrives in the past and waits 3 seconds, he sees himself, but he does not see himself traveling into the future. How is this possible?

[zapatos]

Why would we expect him to see himself traveling into the future?

[questionposter]

Why would we expect him to see himself traveling into the future?

 

(It's a paradox, which is why time travel doesn't exist,) but imagining time travel was true, he would see himself because that's where he was standing in the past at those 4-dimensional coordinates. But if that was the past, why doesn't he see the same exact thing happening again?

Edited March 24, 2012 by questionposter

[Joatmon]

Perhaps when he travels 3 seconds into the past he is exactly where he was 3 seconds ago and is 3 seconds younger. Perhaps there is only one of him, and that one has not yet arrived 3 seconds into the future and doesn't yet know what he is going to do after 3 seconds pass.

[zapatos]

(It's a paradox, which is why time travel doesn't exist,) but imagining time travel was true, he would see himself because that's where he was standing in the past at those 4-dimensional coordinates. But if that was the past, why doesn't he see the same exact thing happening again?

Sorry, don't mean to seem dense.

Is it that he "does not see himself travelling into the past"?

[questionposter]

Sorry, don't mean to seem dense.

Is it that he "does not see himself travelling into the past"?

 

That's correct, he doesn't see himself traveling into the past, but he still saw himself.

[md65536]

That's correct, he doesn't see himself traveling into the past, but he still saw himself.

Why couldn't he see something like a pair-production of a (duplicate) self and an anti-self, spontaneously created, and then 3 seconds later he sees himself collide with his anti-self and annihilates, leaving only the duplicate self continuing on?

 

I think this type of thing can be described in quantum mechanics, so I don't see how it can show that time travel is impossible.

 

 

But then I suppose the question changes to another philosophical puzzle: Would an exact duplicate of one's "self" be oneself? Or would you say that the simultaneous existence of two duplicates means there are two consciousnesses, and the annihilation of one means that time travel of a consciousness is impossible? But then you can keep changing the puzzle---how do we know that a conscious "self" that wakes up one day is even the same self that went to bed the previous night, etc---and I don't think there are easy and certain conclusions.

[John Cuthber]

If I travelled 3 seconds in time then I'd turn up roughly a hundred kilometres away because of the earth's orbital motion.

[questionposter]

Why couldn't he see something like a pair-production of a (duplicate) self and an anti-self, spontaneously created, and then 3 seconds later he sees himself collide with his anti-self and annihilates, leaving only the duplicate self continuing on?

 

I think this type of thing can be described in quantum mechanics, so I don't see how it can show that time travel is impossible.

 

 

But then I suppose the question changes to another philosophical puzzle: Would an exact duplicate of one's "self" be oneself? Or would you say that the simultaneous existence of two duplicates means there are two consciousnesses, and the annihilation of one means that time travel of a consciousness is impossible? But then you can keep changing the puzzle---how do we know that a conscious "self" that wakes up one day is even the same self that went to bed the previous night, etc---and I don't think there are easy and certain conclusions.

 

Why would traveling back in time turn normal matter into anti-matter?

Also, the duplicate is one's self at past 4-dimensional coordinates.

If I travelled 3 seconds in time then I'd turn up roughly a hundred kilometres away because of the earth's orbital motion.

But then you wouldn't be able to see yourself in that past 3 second span because your so far away.

[michel123456]

Nonsense.

If you were to travel 3 sec in your own past, you would not duplicate into another you. Duplication would be a transgression of the law of conservation of energy.

 

Imagine that it is happening: at 12.00.00 you see "puff" yourself being duplicated, and after 3 sec, at 12.00.03, one of your two "yourself" is disappearing. For 3 seconds, the energy contained in all the atoms of your body has been duplicated: it is physically impossible.

 

What is possible is this: you go 3 sec. in your past and becomes 3 seconds younger. There are no 2 yourselfs, but only one "you", younger. After 3 seconds, things continue naturally.

And if ,during this time travel, you cannot take your memories with you, it is pretty much as if nothing happened at all.

Edited March 25, 2012 by michel123456

[questionposter]

Nonsense.

If you were to travel 3 sec in your own past, you would not duplicate into another you. Duplication would be a transgression of the law of conservation of energy.

 

Imagine that it is happening: at 12.00.00 you see "puff" yourself being duplicated, and after 3 sec, at 12.00.03, one of your two "yourself" is disappearing. For 3 seconds, the energy contained in all the atoms of your body has been duplicated: it is physically impossible.

 

What is possible is this: you go 3 sec. in your past and becomes 3 seconds younger. There are no 2 yourselfs, but only one "you", younger. After 3 seconds, things continue naturally.

And if ,during this time travel, you cannot take your memories with you, it is pretty much as if nothing happened at all.

 

How about the energy you put into traveling into the past is why your aloud to exist in the past? And up until you travel into the past again, you disappear form the present, and thus energy is conserved since the energy your duplicate added into going into the past again is in the past and not in the present.

It's technically an infinite paradox.

Edited March 26, 2012 by questionposter

[michel123456]

How about the energy you put into traveling into the past is why your aloud to exist in the past? And up until you travel into the past again, you disappear form the present, and thus energy is conserved since the energy your duplicate added into going into the past again is not in the past and not in the present.

It's technically an infinite paradox.

Ha! Ask Iggy if you can add energy from the same object at different time frames.

 

Hint: you can't.

[md65536]

What is possible is this: you go 3 sec. in your past and becomes 3 seconds younger.

Thank you for correcting me. I was not aware that this was possible.

 

Yes, I suppose spontaneous pair-production of a large(mass and/or time)-scale object would be impossible... "Virtual particles exhibit some of the phenomena that real particles do, such as obedience to the conservation laws.

[...] allows existence of such particles of borrowed energy, so long as their energy, multiplied by the time they exist, is a fraction of Planck's constant." [http://en.wikipedia.org/wiki/Virtual_particle]

 

So I guess questionposter is right, that if this type of time travel were also possible (in addition to the description that you say is possible), it would require some energy input in order to do it (it would not involve virtual particles, nor effortless time travel). The energy input would occur in the earlier, "past" time, and an energy output would occur in the later time. Your Delorian would not require plutonium stolen from terrorists to make the initial jump into the past, but rather it would disappear in a burst of released energy as it collides with an anti-matter Delorian already travelling backward through time to 1955. It would require energy from where (when) it appears, not from where it disappears.

[michel123456]

Thank you for correcting me. I was not aware that this was possible.

(...)

I do that all the time.

[md65536]

I do that all the time.

You go 3 sec. in your past and becomes 3 seconds younger?

 

Oh you mean correcting me. Yes. To be clear I meant that I did not know that going 3 seconds into your past was actually possible.

 

 

[questionposter]

Ha! Ask Iggy if you can add energy from the same object at different time frames.

 

Hint: you can't.

 

 

It should be perfectly logical to change 3 dimensional location of energy in different 4 dimensional coordinates.

 

You go 3 sec. in your past and becomes 3 seconds younger?

 

Oh you mean correcting me. Yes. To be clear I meant that I did not know that going 3 seconds into your past was actually possible.

 

 

 

That doesn't explain why the time traveler doesn't see the process repeeating...

Edited March 26, 2012 by questionposter

[michel123456]

You go 3 sec. in your past and becomes 3 seconds younger?

 

Oh you mean correcting me. Yes. To be clear I meant that I did not know that going 3 seconds into your past was actually possible.

 

Sorry.

I ment that I make mistakes all the time. Your post was so evidently right and mine wrong that I thought it was evident.

That makes a double mistake.

 

It should be perfectly logical to change 3 dimensional location of energy in different 4 dimensional coordinates.

(...)

?? could you elaborate on this?

[md65536]

Sorry.

I ment that I make mistakes all the time. Your post was so evidently right and mine wrong that I thought it was evident.

That makes a double mistake.

Ah no worries, I don't think any of us are right but they're all interesting ideas.

 

That doesn't explain why the time traveler doesn't see the process repeeating...

Oh, I see now what you are getting at.

 

Then, I think the answer to the puzzle would be this:

The hypothetical time traveller doesn't experience repeating the process because he is going forward through time during the entire process. The time traveller should have his own clocks that are independent of others---otherwise I don't think it would be time travel. If he is able to acquire information and not lose it (thereby remembering experiencing anything at all) then he is changing, and ageing, the whole time that he is observing whatever he ultimately remembers.

 

 

I don't think it's physically possible to happen this way, though, so I agree there would be paradoxes.

[questionposter]

Then, I think the answer to the puzzle would be this:

The hypothetical time traveller doesn't experience repeating the process because he is going forward through time during the entire process. The time traveller should have his own clocks that are independent of others---otherwise I don't think it would be time travel. If he is able to acquire information and not lose it (thereby remembering experiencing anything at all) then he is changing, and ageing, the whole time that he is observing whatever he ultimately remembers.

 

 

I don't think it's physically possible to happen this way, though, so I agree there would be paradoxes.

 

It's clever, but I specifically stated he/she time traveled went backwards in time, not forwards. Your on the right track though.

?? could you elaborate on this?

 

If a ball is traveling two miles per second, and starts at t=0, then at the time coordinate t=0 the ball is no further away from where it started. But, if we go to t=2, the ball is 2 miles way from where it started.

Objects are 4-dimensional at least, you need at least 4 coordinates to describe them in the universe. If you try and only use 3 dimensions the universe is static.

Edited March 26, 2012 by questionposter

[michel123456]

(...)If a ball is traveling two miles per second, and starts at t=0, then at the time coordinate t=0 the ball is no further away from where it started. But, if we go to t=2, the ball is 2 miles way from where it started.

Objects are 4-dimensional at least, you need at least 4 coordinates to describe them in the universe. If you try and only use 3 dimensions the universe is static.

(bolded mine)

No, it is flatland, incorrectly described as a 2D world because the narrator forgot the time dimension.

 

Not to mention that on the basis of some interpretations, the 4D world we live in is static too, see the block universe.

Edited March 27, 2012 by michel123456

[questionposter]

(bolded mine)

No, it is flatland, incorrectly described as a 2D world because the narrator forgot the time dimension.

 

Not to mention that on the basis of some interpretations, the 4D world we live in is static too, see the block universe.

 

I don't know if you saw the huge words "philosophy of time", but I suppose just because time is passing doesn't mean things have to move, but it does allow motion to happen and theoretically different things exist in different 4 dimensional coordinates.

Edited March 27, 2012 by questionposter

[Creationists]

Well he didn't travel to the future in the first place. You said that he travelled 3 seconds into his past. And then you said he didn't see himself travel into the future. I'm not sure if this is correct, but I don't see how he could see himself going into the future if he didn't go into the future in the first place, he went into the past, not the future.

 

Imagine the scene, a person travels three seconds into his past. Then he waits three seconds and sees the man going back into the past, not the future. You said he didn't see himself travel into the future.

[ElijahCross]

Maybe I'm thinking in too cheeky or lateral a manner, but I think a soulution could be that our time traveler was looking into a mirror.

[Purgatory]

I wonder why we think we would see ourselves if we travel back in time. If I think about it there is no real concept of time. We talk about travelling back 3 seconds but what is that really? We defined time to keep track of events on earth and it is very nearly constant (or we just do not notice any changes in our definition of time). Time for everyone reading this differs slightly (in the sense that your seconds and my seconds are essentially not the same) and we know this to be undeniable true.

 

but I digress... If I can change my position in 3D space why can I not travel in time as well? What I mean by this is why does a paradox have to exist if I move through time. I think our understanding of why things seem to move forward in "Time" is the issue. Why can we not treat time as just another dimension that we can only perceive to move forward in? If I go backwards in time why would that start to effect the future? I guess if you could move backwards in time you would be able to see every possible out come of every possible event . But the main question is that it is "you" travelling back in time and in a sense why can we not look at it as you moving in 3D space, but a little bit more complicated. It could be something that we just cannot comprehend, yet.

 

The best time travel theory I've heard is this:

 

If we created two wormholes connecting two points of space together. We send one of the wormholes on a spaceship travelling at the speed of light for 20 years. In theory the wormhole on the spaceship is travelling into the future "slower" than that of the wormhole that remained on earth. i,e 20 years have past on the spaceship and 200 years on earth. If the spaceship now returns to earth with the one wormhole being years ahead of the other does that quantify time travel if we move between the wormholes? Because in essence the the wormholes can be next to each other but are separated only by "time".

 

To elaborate: if someone on the spaceship went through the wormhole they would be many years in the future on earth, and if they went back a little while later almost nothing would have happened on the spaceship.

 

 

Still even with this I can see paradoxes arising... but it would be interesting to know what would really happen.

 

Interesting topic ;p

[WWLabRat]

I had the same idea as ElijahCross. I think it would be easily possible if he were looking into a mirror. Although at that point he would be put into an infinite loop. Because the original time he was there he was just looking into a mirror then every single time he relives those three seconds he would be forced to look directly into the mirror again until he was transported back three seconds to look into a mirror again and again and again endlessly.