Could we only go back in time until the point where the time

[saenbateman]

Could we only go back in time until the point where the time machine was created?

I've known about this idea for many years but I've only just started to see if it has any real merit to it.
I'm a avid enthusiast when it comes to physics.

The few problems I have with this idea is.
1. the time machine has it's own time and with what ever method you choose to go back in time, the time machine plus its content will be in a sort of status and shouldn't be effected by the time dilation.

2. If the time machine did itself have to go back in time, wouldn't the instant it went back it would come to a point were it wasn't going back in time?

3. Not as much as a crux, but when do you define created?

It will be good hearing what you say LoR, hope you can help.

 

[Salv]

Well, seeing as a time machine can never go back in time, only forward. I guess your time machine can abide to it's own rules. I would send my time machine back 11 billion years before The Big Bang.

 

[CupOfWater]

I've read some very interesting stuff about a professor that's working on a time machine, where he can use extreme powerful lasers to bend the spacetime into a swirl. Such a time machine is thought to exists right outside black holes, where matter is spinning so fast that the same effect is created.
Anyways, he's saying that we will only be able to send stuff back to the time that the time machine was first turned on. So, maybe when he turns it on for the first time, he'll get a crapload of stuff coming through it! :lol:

 

[DrunkCat]

Eh, I'm in the camp that says time travel is impossible period. Outside from pseudo-timetravel like freezing yourself of course.

 

[Shaedys]

What would be cool is travelling faster then light somehow(wormholes?)
And then seeing the Earth as it was long, long ago.

 

[Salv]

Eh, I'm in the camp that says time travel is impossible period. Outside from pseudo-timetravel like freezing yourself of course.

I think it was Richard Feynman who was taking on questions after an informal talk.
Someone asked him if it would be possible to build a some sort of time machine. He responded with something on the lines of. "We're always moving forward in time, so in effect the chair you're sitting on is a perfectly good time machine."

 

[MRaverz]

I've read some very interesting stuff about a professor that's working on a time machine, where he can use extreme powerful lasers to bend the spacetime into a swirl. Such a time machine is thought to exists right outside black holes, where matter is spinning so fast that the same effect is created.
Anyways, he's saying that we will only be able to send stuff back to the time that the time machine was first turned on. So, maybe when he turns it on for the first time, he'll get a crapload of stuff coming through it! :lol:

This raises a question.

Could you build a time machine and sent enough stuff through to when it was first built to destroy it?

 

[Demojen]

You can't go back in time.
While you may perceive the different dimensional state as a different time frame, to cross the time-dimension would give birth to another dimension. Another time-line as it were.The thread just becomes more entangled.

One dimension interpreted as the past of this one turns out to had just been the present of another dimension.
The downside is that even if you were to change the past in this alternate dimension, you couldn't effect the present dimension.

In my opinion, our best bet is to try and see the future.

 

[borrofburi]

You can't go back in time.
While you may perceive the different dimensional state as a different time frame, to cross the time-dimension would give birth to another dimension. Another time-line as it were.

Hey look at me, I can shout things and claim them as fact! /s But seriously, you're just saying stuff that you derived from a thought experiment with no *evidence*.


Anyway, time travel to the past is theoretically possible, but not in the way anyone here is thinking it is: not as a continuous "I want to go back in time 500 years" system, but as singular "i want to go back in time to when this time machine was first turned on". The primary theoretical way to create a time machine is to create two linked wormholes, move one to the middle of nowhere, and move one next to a black hole so that it effectively stops in time. Then, the first wormhole will always link to a second wormhole that's actually in the past.

Though even this professor's time machine works in a similar manner, I'm sure.

Long story short: all theoretically possible time machines work such that you can only travel back in time to when the machine was first turned on.

 

[scalyblue]

Heck, if you want to take a thought experiment a different way perhaps time travel could be self fulfilling to the functionality of the machine.

There's only one major problem with time travel that most sci fi doesn't consider, and it's that time and space are moving forward and to move forward in one you must also move forward in another...so if you *were* to travel back in time--let's say a year--let's say a wizard did it, the Earth wouldn't be where you traveled to, it would be wherever it spatially was the year prior, which isn't where it is at that point.

 

[Icefire9atla]

Heck, if you want to take a thought experiment a different way perhaps time travel could be self fulfilling to the functionality of the machine.

There's only one major problem with time travel that most sci fi doesn't consider, and it's that time and space are moving forward and to move forward in one you must also move forward in another...so if you *were* to travel back in time--let's say a year--let's say a wizard did it, the Earth wouldn't be where you traveled to, it would be wherever it spatially was the year prior, which isn't where it is at that point.

Technically the earth would be in the same place as it was a year ago (with slight differences due to orbital fluctuations), although the point still stands.

 

[xman]

You really need to see this movie ... a couple of times at least. That'll get you thinking straight about this kind of machine.

Personally, I am not a fan of the multiple timelines idea. Too messy. If going back and changing the past changes your world line then so be it I say. Killing your grandfather before you were born just means that you will not be born. In such a situation the universe may not let you return to your time although you might be able to wait it out and be around when you used to be, just older. the universe also might not let you go back if there is a chance of you changing anything. For this reason, a natural Einstein-Rosen bridge would likely lead somewhere/somewhen else in this or another universe where you have zero probability of affecting your own past. http://en.wikipedia.org/wiki/Novikov_self-consistency_principle

 

[Master_Ghost_Knight]

I don't think that you can only travel in time in one direction (or out of reach of light cone), or else you would have to necessarilly violate causality.
I didn't knew that made something similar into a principle ("Novikov self-consistency principle") as posted by Xman, but it is something that sooner or later someone that as taugh enough about the subject has to consider.

 

[borrofburi]

http://en.wikipedia.org/wiki/Novikov_self-consistency_principle

I don't really care for that principle. I don't know if it comes from mathematics or not, but it seems to be some people opinions on the problems of paradox. I think primer did it best in that going back in time rewrites history. It's kind of like an alternate universe, but it's more like a re-writing of a single one and doesn't actually require multiple universes.

Basically, if you kill your baby-self, it doesn't make timetraveler-you stop existing, but if you freeze yourself (or travel at light speed) so you can return to your old "present" none of your life's work will have existed, whether that was bringing friends and family together or building a time machine; you just rewrote history, that's all, no paradoxes involved because time isn't linear or complete like that.

 

[scalyblue]

Heck, if you want to take a thought experiment a different way perhaps time travel could be self fulfilling to the functionality of the machine.

There's only one major problem with time travel that most sci fi doesn't consider, and it's that time and space are moving forward and to move forward in one you must also move forward in another...so if you *were* to travel back in time--let's say a year--let's say a wizard did it, the Earth wouldn't be where you traveled to, it would be wherever it spatially was the year prior, which isn't where it is at that point.

Technically the earth would be in the same place as it was a year ago (with slight differences due to orbital fluctuations), although the point still stands.

No it wouldn't, the sun moves around the center of the milky way faster than the earth revolves around the sun.

 

[scalyblue]

http://en.wikipedia.org/wiki/Novikov_self-consistency_principle

I don't really care for that principle. I don't know if it comes from mathematics or not, but it seems to be some people opinions on the problems of paradox. I think primer did it best in that going back in time rewrites history. It's kind of like an alternate universe, but it's more like a re-writing of a single one and doesn't actually require multiple universes.

Basically, if you kill your baby-self, it doesn't make timetraveler-you stop existing, but if you freeze yourself (or travel at light speed) so you can return to your old "present" none of your life's work will have existed, whether that was bringing friends and family together or building a time machine; you just rewrote history, that's all, no paradoxes involved because time isn't linear or complete like that.

What if part of your life's work was the invention of the time machine that brought you back?

 

[borrofburi]

I don't really care for that principle. I don't know if it comes from mathematics or not, but it seems to be some people opinions on the problems of paradox. I think primer did it best in that going back in time rewrites history. It's kind of like an alternate universe, but it's more like a re-writing of a single one and doesn't actually require multiple universes.

Basically, if you kill your baby-self, it doesn't make timetraveler-you stop existing, but if you freeze yourself (or travel at light speed) so you can return to your old "present" none of your life's work will have existed, whether that was bringing friends and family together or building a time machine; you just rewrote history, that's all, no paradoxes involved because time isn't linear or complete like that.

What if part of your life's work was the invention of the time machine that brought you back?

Then it doesn't get built. Again, you're thinking of time as a linear fixed entity; while I explicitly said that such a concept of time doesn't require multiple universes, it certainly is the easiest way to conceptualize it: as far as this universe/timeline is concerned, you popped into existence on the day you went back in time to, period. It has no concern of what led to you popping into existence, it doesn't matter that you came from that time-line's previous future, because that future no longer exists, it doesn't matter if you kill yourself and your time machine no longer exists, because the universe/timeline doesn't care how you got there. Easiest to conceptualize it as an alternate reality, but in fact does not necessarily require that multiple universes actually exist. Preventing the time travel machine from being built is no more a problem than disassembling the car that brought you to work, you're still at work, you just no longer have a way to get to work tomorrow.

tl;dr it doesn't matter if you no longer build the time machine, for it to be a pardox requires time to be some sort of fixed entity.

 

[Durakken]

Your questions' answer depends on the time machine and what type of time travel. Some types make it impossible to go further back, other make it possible.

 

[xman]

Technically the earth would be in the same place as it was a year ago (with slight differences due to orbital fluctuations), although the point still stands.

No it wouldn't, the sun moves around the center of the milky way faster than the earth revolves around the sun.

You're sending someone somewhen else in time and you're worried about where they end up?!
So build your time machine in a rocket ship and you can cover both bases at once.

 

[scalyblue]

You're sending someone somewhen else in time and you're worried about where they end up?!
So build your time machine in a rocket ship and you can cover both bases at once.

I can just picture Michael J Fox in that radiation suit, behind the wheel of the delorean, discovered floating through deep space by humans in the year 3000. :twisted: :lol: