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 ;)
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 ;)