Greg Egan on Nostr: In Newtonian gravity, if you drop an object down a borehole in a ball of uniform ...

In Newtonian gravity, if you drop an object down a borehole in a ball of uniform density it will oscillate at the same rate as an orbiting body grazing the surface.

In General Relativity that perfect match is lost … unless you drop the object from higher up and raise the orbit.