Slartibartfast: "Perhaps I'm old and tired, but I think that the chances of finding out what's actually going on are so absurdly remote that the only thing to do is to say, 'Hang the sense of it,' and keep yourself busy. I'd much rather be happy than right any day."
Arthur: "And are you?"
Slartibartfast: "Ah, no. (laughs) Well, that's where it all falls down, of course."
A computer simulation of what happens when two spiral galaxies collide. At various points, the simulation stops to show a comparison to pictures of actual galaxy pairs in the midst of this process, as seen from the Hubble telescope. In a few billion years, the Milky Way might undergo this process, merging with our largest neighbor, the Andromeda Galaxy.