2050: Where will the Fate of Mankind Go?

The ultimate fate of the Earth (if it survives) depends on what happens. On a time scale of 1015 (1 quadrillion) years the remaining planets in the Solar System will be ejected from the system by close encounters with other stellar remnants, and Earth will continue to orbit through the galaxy for around 1019 years before it is ejected or falls into a supermassive black hole. If Earth is not ejected during a stellar encounter, then its orbit will decay via gravitational radiation until it collides with the Sun in 1020 (100 quintillion) years. If proton decay can occur and Earth is ejected to intergalactic space, then it will last around 1038 (100 undecillion) years before evaporating into radiation.