In black holes this force is so strong that not even light can escape
The idea of a body so massive that even light could not escape 
was first put forward by John Michell in a letter written in 1783 to Henry 
Cavendish... [DOC] [TLE] Black holes have a gravitational force so strong that even light can't ... [PAR] Dude, the video itself says that its a simulation ... Black holes have a gravitational 
force so strong that even light can't escape it.