How small can we make a gyroscope and still have it respond to gravity? Maybe a few molecules? Could this be a path to unify Quantum Mechanics and General Relativity - through experimentation, since theory seems to have failed?
The gyroscope responds to rotation and not gravity. It requires a ring (or two) for the light to circulate in so I don't think they will be molecular sized for reasonable wavelengths of light.
You're right, I believe I'm thinking of accelerometers.