On Mon, 05 Dec 2016 13:35:07 -0000, Robert Green wrote:

"DerbyDad03" wrote in message

stuff snipped

Wall clocks, table clocks, pictures with clocks in them. Some worked, some
didn't. Many ticked, many chimed.

I recently learned that in a room of grandfather clocks, they will (mostly)
all eventually synchronize. Can you guess why?

I'd guess they have to be in physical contact, or at least on the same wall. Then the vibration will pass between them, and they'll swing in time, like carrier bags annoyingly swing in time with your running. I'm surprised it's enough effect though, given the mass of a wall is far greater than a pendulum. Maybe it only works with big clocks and a long time period.

--
If you think people aren't creative, watch them try to re-fold a roadmap.