Recently I started reading on thermodynamics and from it only I saw that utilizing the second law of thermodynamic we could define the arrow of time. And not only the arrow but we could also try to define time utilizing the second law. We could state, that time is used to sequence events where there is change of entropy. This is also evident in already major theories such as that relating to the heat death of the Universe wherein once the Universe reaches the state of maximum entropy, time breaks down. Because at a equilibrium, only quantum particles would be left whose density would fluctuate from region to region but no consolidate change would happen in the universe hence time will make no sense in such a scenario. Now coming to the second part of my question, that is how time behaves in different circumstances. I know that behavior of time may be found out by results of the general theory of relativity. But I would like a discussion or clarity, That what is time inside the event horizon of a black hole On or inside the singularity of a black hole Assuming the end of the Universe is a heat death, will time break down as I have mentioned above or will only the sense of time break down and time will still be there. Finally, Could someone also help me with the concept of black hole entropy, it is stated that the black hole entropy is directly propotional to its surface area. Can someone give an example of a body being pulled in the black hole.