@inkican Going back in time would require more energy than is available in the universe, for going faster than the speed of light, which is impossible. That’s the basis in the theory (should be called ‘law’ by now) of relativity.
Backwards time travel would obviously interfere with causality in creating an alternative past, which would lead to a different present. So it’s a good thing that it’s physically impossible, despite what a desperate astrophysicist believes.
The idea is that you can go backwards in time by going faster than light. The speed of light is actually the speed of information itself - so if you could go faster than that, you’d be going backwards in time.
However, Einstein showed that nothing can accelerate to the speed of light. You’d need infinite energy to actually reach the speed of light, and infinite energy is assumed to not be possible.
I wonder if there is a meaningful difference between your example, and the technology with which the JWST uses to view light in the past. Rather, if the later is something we can use for time travel ;)
@inkican Going back in time would require more energy than is available in the universe, for going faster than the speed of light, which is impossible. That’s the basis in the theory (should be called ‘law’ by now) of relativity.
Backwards time travel would obviously interfere with causality in creating an alternative past, which would lead to a different present. So it’s a good thing that it’s physically impossible, despite what a desperate astrophysicist believes.
How do we know how much energy time travel would take?
The idea is that you can go backwards in time by going faster than light. The speed of light is actually the speed of information itself - so if you could go faster than that, you’d be going backwards in time.
However, Einstein showed that nothing can accelerate to the speed of light. You’d need infinite energy to actually reach the speed of light, and infinite energy is assumed to not be possible.
I wonder if there is a meaningful difference between your example, and the technology with which the JWST uses to view light in the past. Rather, if the later is something we can use for time travel ;)