[chahihkh] On earth orbit

Construct an evacuated tube over a great circle around the Earth.  Have a vehicle traveling so fast within it that it experiences zero gravity: it is orbiting the earth at the surface.

This represents an engineering challenge so massive it will probably never be built.  Probably a political challenge too as the tube goes through many countries.  Motivation was to provide an easy way to provide long experiences of zero g for amusement (or perhaps science).

Does it have to be at the equator?  How strong are Coriolis forces if not at the equator?  If not at the equator, what about the oblateness of the earth?

Doing it around smaller astronomical bodies might be more feasible, though we have to get to them first, in which case, why not just experience zero g in space getting to them?

Previously, black holes in low orbit.