Humanity learned to measure time by watching it fall.
Well at least gravity did most of the work for them. It pulled the sand downwards, pulled shadows across stone, pulled days into nights with comforting consistency every time. Time moved because Earth demanded it.
The Hourglass.
Two chambers. One direction. A promise that above will eventually transfer below.
But when humanity left that world. The sand stopped obeying by those standards.
In orbit, nothing falls. There is no down to surrender to. An hourglass becomes decoration—beautiful yet useless.
So humanity abandoned letting time fall and instead replaced grain for numbers.
Digits blink without warning. Seconds vanish without weight.