Psychronometrics

The curve never touches the floor. Push the frame to a googol years and the two could hold their speed for the whole age of the universe and drift apart by a few billionths of the width of one proton — but they do drift, and the older is still, by a margin nothing could measure, the older. Sameness is the limit, never the arrival. Only at eternity do the two clocks agree, and eternity is the one frame of reference no one occupies.