Can we really travel back in time using a wormhole?

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Discussion Overview

The discussion revolves around the theoretical possibility of traveling back in time using wormholes, examining the implications on thermodynamics and the nature of time itself. Participants explore concepts from general relativity (GR) and the relationship between entropy and time, as well as the energy requirements for such travel.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants question whether wormholes can be used for time travel and how this idea interacts with the first law of thermodynamics.
  • One participant asserts that according to general relativity, entering a wormhole does not allow one to escape the singularity while maintaining a positive timelike trajectory.
  • Another participant suggests that the concept of a 'past' may not exist due to the inherent increase of entropy over time, implying that time travel to the past is not feasible.
  • Questions are raised about why entropy appears to only increase in one temporal direction, with speculation on the nature of disorder and time's unidirectional flow.
  • Some participants mention that while variations of general relativity might support the existence of wormholes or warp bubbles, the energy required to utilize them could exceed what is available in the universe, rendering them impossible.
  • There is a discussion about the relationship between the second law of thermodynamics and general relativity, questioning whether one is more fundamental than the other in the context of time travel.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of time travel via wormholes, the nature of the past, and the implications of thermodynamics. No consensus is reached on these topics, and multiple competing views remain present throughout the discussion.

Contextual Notes

Participants highlight limitations in understanding the relationship between thermodynamics and time travel, as well as the unresolved nature of energy requirements for wormhole manipulation. The discussion also reflects uncertainty regarding the fundamental nature of the laws governing time and entropy.

Imparcticle
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Is it true that theoretically, you can use a wormhole to travel into the past?
How so? Does this whole idea not violate the 1st law of thermodynamics?
Could the past already somehow exist? (i don't think so, but just for the record, I'd like your opinion.)
 
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According to what theory; can you name this theory for us? According to GR, as far as I know, you cannot start on a positive timelike trajectory, enter a wormhole, and escape the singularity.
 
i think you're right in saying it's basically a thermodynamics issue...i don't think there is really a 'past' to travel to, you can't undue the entropy inherent in time and motion...traveling into the future happens every time you move a muscle...
 
And why does entropy only "move" (can't think of the right word at the moment) in one [temporal] direction? Is it because something can only increase in disorder, never decrease and not do both simoltaneosly?
 
Great questions. Although some strange variations on General Relatvity seem to support wormholes or warp bubbles, i believe they also require more energy to implement than is present in the universe. By my standards, that makes it impossible.

As to the thermodynamic arrow of time: that is one of the great mysteries. All known laws are time-symmetric. So where does the arrow come from?

Lastly, it is not clear that the 2nd law actually prevents time travel. The question essentially becomes: is the 2nd law more fundamental than GR? Over vice versa? Or neither?
 

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