Gravity

[murtags2]

Is it actually possible to prove,beyond all doubt, that gravity exists or is it just a theory that can't be falsified?

[Rev. Green]

Neither of two possibilities for gravity has yet been proved. Einstein thought it was caused by curvature of space. Currently, an exchange particle, the graviton, is favoured.
I'm with Einstein because the magnitude of the gravitational force is always proportional to mass - the same as other pseudo forces (centrifugal force, Coriollis force, etc.).