How does Stephen Hawking use imagery in A Brief History of Time?

Example of Imagery:

"The event horizon, the boundary of the region of space-time from which it is not possible to escape, acts rather like a one-way membrane around the black hole: objects, such as unwary astronauts, can fall through the event horizon into the black hole, but nothing can ever get out of the black hole through the event horizon. . . . One could well say of the event horizon what the poet Dante said of the entrance to Hell: 'All hope abandon, ye who enter here'" (p. 89).