Hi all, I was just wondering about gravity (in the General relativistic sense). If there was a large barrier between two large objects, would the effect of gravity pass through the barrier?? For example, if we put a large barrier between the earth and the moon (assume the barrier is massless so it does not have any gravitational effect), would the moon spiral off?? (see attached picture) Also, If the sun comes between earth and another planet (say mars) does the gravitational effect of mars on earth (and also earth on mars) get blocked by the sun for a while??? If so, the gravitational difference should only occur as we 'see' mars going past the sun, as in the gravitational effect travels at the speed of light. Has this been observed?? Thanks, P.S.