Any idea how does it work? video:

https://youtu.be/M8rrWUUlZ_UNeed to keep in mind:

Fact 1: Multiple experiments prove there's no curvature, so it proves earth is flat.

Fact 2: Michelson-Morley experiment proves stationary earth. But they rejected it and denied the existence of ether for philosophical reasons. Later Einstein came up with his theory to save rotation of earth.

Assuming earth is a globe and then using mathematical calculations can provide necessary consistency to explain different phenomenas.

What could be possible explanation on FE of this pendulum phenomena?