outer world

There are many ways to travel in future. But traveling in past is somewhat practically impossible.             These are some of the ways that we can travel in future but some are still hypothetical and theortical:- 1) By approa ching speed of light :--            Time slows down for objects traveling close to the speed of light and the time stops for objects traveling at the speed of light so if we travel faster then the speed of light then time must go backwards. But according to Einsteins mass-energy relationship that is E=mc² no object can travel faster then the light because on approaching the speed of light, objects starts increasing in mass rather than speed and it would take an infinite time and amount of energy for an object to achieve speed of light. This is why we can't travel back in time( that is in past). So therefore if we try to approach close to speed of light then we can ...

Formation of a black hole :—                 the space the massive stars which remains stable for long time is due the production of heat from the nuclear reactions taking place inside star which is also responsible to balance the gravitational attraction.        However when the stars run out of the hydrogen and other nuclear fuels it will start cooling and the gravitation wins over it and then the  star starts collpsing all it's mass inwards to a central point. This central point gets smaller and denser as all the mass of the star is squashed into a single tiny point.            But not all stars which have collapsed will transform into a black hole.  In order to become a black hole it must compress below a certain radius called schwarzschild radius . It is given by        ...