What are some interesting facts about Universe?

by Aditya Pulugurtha
According to Stephen Hawking, time travel might be possible in two ways in future. According to him,

1. First theory is that time slows down as we approach heavy objects.
So in the future if we can manage to find a black hole that we can go near to, according to this theory, we can slow down the time. After spending just few days near it and returning to earth, people on earth would be many years ahead of us.
A black hole as we know from science fiction stuff, absorbs even light into it, there by it has infinite density and unimaginable mass.

2. Second theory is that some how if  we can beat the light by a large amount in a race, we can slow down the time. Consider a train that travels at a great speed ( obviously it can't beat the light) such that it can rotate round the earth at a rate of say 7 times every second, then some strange things happen. Now obviously light inside the train has a relative velocity compared to every light ray outside, very high. So the nature makes some changes in the other dimensions I.e, time so as to completely nullify the effect of higher velocity than light. It means time becomes slower so as to nullify the extra velocity of the light achieved inside the train. In this way also we can manipulate the time.

Source: Discovery Science channel