Universe

Black holes are massive bodies. And a massive body bends space towards it. Light can't travel outside the space so If light falls in black holes it will continue falling inside (* towards there is no inside, blackholes are not hollow) if we consider that space is so much squeezed it may be converted into mass orr light can escape from another side of a blackhole (white holes in some parallel universe with opposite physics rules) so light never comes back from black holes.