When somebody crosses the horizon of a blackhole, the person would have the privilege to travel backwards in time (as shown in the movie 'Interstellar'). What are the possiblities of such a person to even survive after getting in a blackhole, and how does he even able to travel in the past. Time travel in the future can definitely be considered due to relativity. Relativity also shows how can time be reversed, but how does a blackhole cause time to be reversed? Can somebody explain me please?