The headlight of the next westbound can be seen for miles down the line, seemingly stationary at first, then slowly growing closer. At some point, you can tell it's on the express track... and moving fast! Then all of the sudden, in a blur of silver and blue and noise and wind, you see it's the hourly Acela Express trainset, you open your shutter for less than 1/1000th of a second, and before the mirror clears the viewfinder again the train has slammed past you and is whooooshing away into the converging lines of the 4-track main to the west.
