There have been many time travelling questions here, but I am not sure if this one specifically has been asked. Is it really possible to travel back in time and is it theoretically possible? This question states that one possibility is that:
They cannot go back in time because it has already happened, and therefore they can only go forward in time.
Is this really true? On the other hand, Wikipedia states this:
Time travel to the past is theoretically possible in certain general relativity spacetime geometries that permit traveling faster than the speed of light, such as cosmic strings, traversable wormholes, and Alcubierre drives.
NASA also states this:
We can't use a time machine to travel hundreds of years into the past or future. That kind of time travel only happens in books and movies. But the math of time travel does affect the things we use every day. For example, we use GPS satellites to help us figure out how to get to new places.
Could anyone provide a detailed answer concerning which is actually correct?
Story:
I am writing a story on where a person travels back in time to prove its possible to the people in the past before getting found and arrested by the future people for "time travelling". But I want to keep the story "factual" and "as real as possible". I'm sure it is somewhat "possible", but I want to make sure the person in my story uses the right method to time travel in the first place, and that time travel is actually possible as well.
Context:
- Year 6814 (not sure if it really matters, just a year that is technologically advanced enough to time travel).
- Future world is technologically advanced enough to time travel to the past version of the same world.
- The past version of Earth is the year 2050, where the technology is better than current standards, but not powerful enough for time travel obviously.
- The future is a complete "utopia" setting, the people there have all the food, water, luxury, and technology they could ever want. There might be a few stranded groups of people who do not really want to live there for which I will not provide any reasons due to the context of this question.
- There is a law in the future to not time travel back in time, if it is even possible for us people in 2022.