Here is what I think about that horse falling on us: I figure it took a little more than four seconds for the horse to travel from the span of the bridge, over three hundred feet above, to where my mother and I stood on the bank of Salmon Creek. During that fall, the earth moved approximately one hundred miles. If you were to walk a straight line for a hundred miles and drop a total of three hundred feet, you wouldn't even realize you were descending in elevation at all. That horse fell one hundred sideways miles.
-- Finn (Twenty Miles Per Second paragraph 7)

Importance: Finn shares his perspective on the dead horse incident and his unique way of looking at things. He thinks that distance is more important than time and sets up his rationale with this example.

That's what that shit on your back looks like, Finn. If a horse with a really big boner...
-- Cade (Five Euros in Dollars paragraph 2)