Time travel may sound as a fiction or movie based story but many scientists are still in search of the answer for time travel. There are certain physicists too that say time travel can be logically possible. Since the time when this topic has been discussed there are many topics that have confused scientists that Is the ‘grandfather paradox’ of time travel, this explains the paradox of a person going back in time to kill his grandfather before he procreates, if this happens then the grandson won’t be born which is a paradox because the grandson has to be born in order to kill his grand-father and the question goes on. So David Lewis says that if time travel happens especially to the past then the time traveler won’t be able to change the history even if he want to. So basically this logical explanation says that a time traveler won’t be able to effect changes in history. Another paradox is of the causal loop where you give the budding Shakespeare a copy of hamlet and he writes and it becomes a celebrated work of Shakespeare in future so if searched through origins this loop will not have a point where hamlet was actually written, this paradox is explained saying that such loops are possible, because the place from where the beginning of information is still not known even in this time where time travel is not possible so it can happen in the past too. Another explanation is that we can travel to the future but cannot travel to the past where time machine was not created for example if time machine was created in 2000 then we can go back as long as 2000 but not anymore than that. If it should be possible to make change in the past then yet another science fiction must come into reality that is the parallel universe, so if a change is made in the past then the new made future will become a new branch in time. All these are only few explanations for time travel being logically possible though any findings that prove a time travel is not done.