What are the energy implications of time travel into the future?

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SUMMARY

The discussion centers on the energy implications of a hypothetical train traveling around the Earth at speeds approaching the speed of light (0.99999998c) to achieve time dilation. It concludes that while passengers on the train would experience one week, 100 years would pass on Earth due to relativistic effects. The conversation highlights that energy is frame-variant, meaning the energy required to power the train differs based on the observer's frame of reference. The concept of length contraction is also crucial, as it allows the train to complete its journey in a significantly shorter time from the passengers' perspective.

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  • Understanding of Einstein's theory of relativity
  • Familiarity with time dilation and its effects
  • Knowledge of kinetic energy and its frame-variant nature
  • Concept of length contraction in relativistic physics
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  • Research Einstein's theory of special relativity
  • Explore the concept of time dilation in practical scenarios
  • Study the implications of length contraction on relativistic travel
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Physicists, students of relativity, science fiction writers, and anyone interested in the theoretical implications of time travel and relativistic physics.

  • #31
What happens if inside the train we build another track that goes in circles, and we repeat this process over and over, would that mean that theoretically we can we can travel all the age of the unvierse in less than a second or a infinitesimal amount of time?
 
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  • #32
Rene Manzano said:
What happens if inside the train we build another track that goes in circles, and we repeat this process over and over, would that mean that theoretically we can we can travel all the age of the unvierse in less than a second or a infinitesimal amount of time?
That would be adding an implausibility on top of an implausibility.

The way to avoid all this implausibility is to just get in a spaceship and leave poor Earth in peace. Your ship has a engine that can run indefinitely. In theory, you could continue to accelerate until the universe flashes by at a billion years a second or faster. There's really no upper limit.
 
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  • #33
DaveC426913 said:
That would be adding an implausibility on top of an implausibility.

The way to avoid all this implausibility is to just get in a spaceship and leave poor Earth in peace. Your ship has a engine that can run indefinitely. In theory, you could continue to accelerate until the universe flashes by at a billion years a second or faster. There's really no upper limit.
Why wouldn't it work though?
 
  • #34
In principle, it would work. But it is implausible that we can build a train to go around the Earth at 99.99+% of the speed of light. Building a nested sequence of such trains is more implausible still. Why make a thought experiment complicated when one can simply imagine the original train going faster and achieving an identical effect?
 
  • #35
jbriggs444 said:
In principle, it would work. But it is implausible that we can build a train to go around the Earth at 99.99+% of the speed of light. Building a nested sequence of such trains is more implausible still. Why make a thought experiment complicated when one can simply imagine the original train going faster and achieving an identical effect?
It would actually complicate the part of my question about powering the train from outside. Won't it? What if i considered a different planet with a huge radius(compared to earth) so will it be possible then?
 
  • #36
Suraj M said:
What if i considered a different planet with a huge radius(compared to earth) so will it be possible then?
OK, so a planet one or two orders of magnitude larger than Earth.
So, instead of a billion g's, you've reduced it to 10 million g's.

Your occupants, rather than being a puddle of jam 1 micrometer thick, are a puddle of jam 100 micrometers thick. :wink:
 
  • #37
Now don't shift this thread to the fiction forum! :olduhh:
 
  • #38
Suraj M said:
Now don't shift this thread to the fiction forum! :olduhh:
It's been in danger of that since sentence 3 of post 1. :biggrin:
 

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