Why time traveling (To the past) is impossible.

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Discussion Overview

The discussion revolves around the concept of time travel, particularly the idea of traveling to the past. Participants explore various theories and arguments regarding the feasibility of time travel, the implications of faster-than-light travel, and the paradoxes associated with altering past events.

Discussion Character

  • Debate/contested
  • Exploratory
  • Technical explanation

Main Points Raised

  • One participant suggests that traveling faster than light would lead to entering a pocket dimension, resulting in a new universe, and argues that time travel to the past is impossible due to the need for negative time.
  • Another participant briefly mentions the idea of racing against space-time to move backward in time.
  • A claim is made that reaching the speed of light requires an infinite amount of energy, which is deemed impossible.
  • One participant acknowledges that while special relativity suggests faster-than-light travel could allow time travel, the requirement for infinite energy makes it unfeasible.
  • The same participant introduces the concept of closed timelike curves from general relativity as a theoretical means of time travel, but questions their existence in the universe and the implications of such travel.
  • A paradox regarding the implications of traveling to one's own past, specifically the "grandfather paradox," is mentioned as a reason against the possibility of changing past events.
  • Another participant critiques the initial theory by emphasizing the impossibility of exceeding the speed of light and challenges the notion of entering a new universe.
  • A comment is made regarding the unwelcomeness of personal theories on the forum.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of time travel, with some arguing against it based on energy requirements and paradoxes, while others explore theoretical frameworks that might allow for it. No consensus is reached regarding the possibility of time travel to the past.

Contextual Notes

Participants highlight limitations related to energy requirements for faster-than-light travel and the theoretical nature of closed timelike curves in general relativity. The discussion also reflects uncertainties regarding the implications of quantum theory on time travel.

Big Evil
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I figured if anyone would understand my theory it's you. Now for one I'd like to make it clear I don't believe in time travel. I believe if you go faster then light (If you can..) you'll rip through the space-time countiuem and slip into a pocket dimension, it folds around you. And you're in a brand-new universe. (Think Sliders but much more lonely..)

Now why is time-travel then impossible? Because traveling to the future requires faster then light speed. Time is measured by speed. The past has already gone. Therfore logic would dictate I'd have to move SLOWER then space-time to "make the clock move backward" and I believe it would be more impossible to go that slow rather then that fast. Because I would have to be having a net-loss in time, negative time, it defies logic. Therby I denounce anymore thought on the idea of traveling to the past to change ANY future..
 
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You have race with space time and beat it to make the clock move backward...
 
to get to the speed of light it takes an infinite amount of energy. Not possible. Read up on the twin paradox will help a little.
 
Big Evil said:
I believe if you go faster then light (If you can..) you'll rip through the space-time countiuem and slip into a pocket dimension, it folds around you. And you're in a brand-new universe. (Think Sliders but much more lonely..)

Ok, apart from a few poetic liberties you took, it is true that if you go faster than light, according to special relativity in a naive formulation, you should go back in time. However, first you need to acquire an INFINITE amount of energy, which you can never obtain (there's only a finite amount of energy available in all of the visible universe). So this is then solved: you cannot go faster than light, so what happens when you do doesn't matter.

But there is ANOTHER way of going "back in time", at least according to GENERAL relativity. General relativity allows you certain solutions which have, what is called, closed timelike curves. This means that if you follow them, at a reasonable speed (that's the "timelike" part) you'll end up at the same EVENT (= space + time point) after a finite time on your watch.
Now, first of all, it is not because the equations of GR allow you such solutions, that these are also present somewhere in our universe. There are people who proposed the postulate that we should restrict ourselves to solutions of the GR equations which do not contain such closed timelike curves. Second, one can wonder what it means to go back to the "same spacetime event" when your watch did count a finite amount of time forward (proper time). Finally, quantum theory might mix in with this and change what exactly it means to be on the same spacetime event. You might indeed just end up in another branch of the wavefunction.

There is a simple reason for not being able to travel to your OWN past and do something, which is well known: it is the "what if I kill my own grandfather" paradox.
 
Big Evil said:
I figured if anyone would understand my theory it's you. Now for one I'd like to make it clear I don't believe in time travel. I believe if you go faster then light (If you can..) you'll rip through the space-time countiuem and slip into a pocket dimension, it folds around you. And you're in a brand-new universe. (Think Sliders but much more lonely..)

There are many flaws in this 'theory'. First of all you are talking about exceeding the speed of light. For you to do so, you'd have to be able to acquire a 'bigger then infinite' amount of energy. This is clearly impossible.

Secondly, the brand new universe aspect. How can you be sure this happens ? I assume you think that because of the large energies that are recquire, spacetime will be curved very severely and this is the 'wrapping around you' part, right ? Well, anyhow it does not really matter because of the above energy argument. You cannot adopt these macaroni-type dimensions alla String Theory for these reasons. If you have this much energy, the entire space time continuum has to wrap around you, also the Kaluza Klein type dimensions that make up every space time point

regards
marlon
 
Personal theories are not welcome on this site.

- Warren
 

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