Bill Hill: On Channel 9, Niners and Homo Sapiens 2.0

This is the first time I had heard of the explanation for why we speculate there is dark matter.
So Newton thought gravity was pulling things down to earth. Einstein said reverse. That spacetime was pushing things into the earth which was gravity. So if spacetime surrounds a planet and "pushes" on it as hard as a planet pushes back - then what gives spacetime its muscle and push?