Growing up watching movies such as, groundhog day and back to the future i never understood the physics behind Time Travel and it was really too confusing for me as I was too young. However, looking back at those movies now I can sort of identify the physics of some of the Time Travel movies. As an introduction, Time Travel theory comes from Einstein’s theory of special relativity. This theory explains that time is not constant and can be changed relative to something else. For example, the famous twin paradox, explains that twin brothers one brother stays at earth and the other brother travels through space with a high speed rocket and then comes back to find his brother is older than him. Special relativity also, explains why we have different time zones in different continents because time changes by our position and speed. Time Travel movies suggest that time can be manipulated to travel through past and future by assuming that they already have a device that is faster than light. In simplified explanation, Time Travel Physics can be possible in real life if we have something that is faster than light to manipulate time. However, Time Travel is still a theory which movies use to visualize and entertain us with how fascinating it is to be true. (some figures under the blog of different paradoxes you can look up if anyone is interested).
The Zeno’s Paradox
The Grandfather Paradox