This is the science on the subject. No conjecture, no science fiction, no speculation. These are scientifically established facts per Relativity.
Ukitaka kuelewa time travel kwa mujibu wa sayansi yetu ya sasa, itabidi uanze na Relativity ya Einstein.
Kwa mujibu wa Relativity ya Einstein.
1. Time is relative, not absolute.
2. Time is relative to space (the observer), speed and gravity.
3. For an object with mass, however small, per relativity, going backwards in time is impossible. Because that will involve going faster than the speed of light. Approaching the speed of light for any massive object means approaching infinity mass, which will require infinity energy.
So first you need to stop time before going back in time. Stopping time = going at the speed of light. Approaching the speed of light for any massive object equals approaching infinity mass. As you approach infinity mass, moving even at very small speed will require infinity energy. So, time travel backwards is impossible because it needs infinite energy.
4. Time travel to the future is easire by using time dilation. If you have twins whose birthdate is the same day, you take Doto and put him in a spaceship that goes at 80% the speed of light to go to Proxima Centauri, the nearest star, Doto could spend 12 years going to Proxima Centauri and back to earth, only to find that the 12 years Doto spent on the spaceship are equal to 120 years on earth because of time dilation (figures not to scale)
If Kulwa and Doto were both 20 years old today 2022 when Doto left earth, Doto would return to earth at 32 years old, only to find earth in the year 2122. To Doto, 12 years have passed, to earth, 100 years have passed.
Here is a chart of time dilation per percent of the speed of light
Here is a link to the page
Time Dilation at Low Speeds - Relativity when flying