On: Large crack in East African Rift is evidence of continent splitting in two

[sannee]

> weather changes would probably have a far greater effect on cable length than the imperceptible drift of the endpoints (which suggests another crazy idea interesting in its own right)

There is a clock running for over a century based on a similar idea: https://en.wikipedia.org/wiki/Beverly_Clock

[userbinator → sannee]

...and the commercial version, which is still in production:

https://en.wikipedia.org/wiki/Atmos_clock

Not cheap (few k$), but not as expensive as some other high-end timepieces either.