Time is like a river, it swifts and shores in one direction

This is a notion with which everyone must be familiar with, the obsession to know more about the universe and how things are happening the way they happen goes way back in 20,000 BC when cosmologist made attempts to describe the force which makes it all stable. Time is one leg of the chair of the universe in which we all stand, thus it is quite dangerous to tamper the force and experiment with it.

Consider this analogy of time and river, both have a unidirectional flow and we are just the boat sailing along whether be time or the river. Travelling backwards against the flow requires a lot of energy like what quoted by the theory of relativity E=mc^2 is the amount of energy we have to achieve, to begin with, time travel.

Now, as you might have a little idea about string theory, which discusses the how the river of time is divided into different streams and the stream which we get depends upon the actions we take in present. 

From the concept of time travel, we can conclude that if we get enough energy we can flow back in time, but if we don't give it in the right direction, we might face consequences. Some of the hypothesis of the event that may follow are :

1. We can end up being an alternate form of reality ( the one we can't relate to from our past)

2. We might alter the space-time and end up having both the different reality come together

3. The concept to enter in an alternate reality may require more energy than to go in our reality of past, hence it might not be achieved

Following it all, it might be difficult to relate but consider like this, you have just started to move the boat against the stream but instead of going to the diversion from where you came in, you chose the alternate stream and thus you are in an alternate past. OR you try to go back to your path from where you came and suddenly the stream takes you to different diversion and you end up in an alternate reality of your time, both of which are equally exciting and terrifying.

My notion to say it as paradox square is because as both time travel and string theory are a big paradox in itself, it's quite difficult to imagine such an event to happen. The only way we can know it all when we get to know how to flow against the flow of time and look it all by ourselves.