OK. Like I said--I'm not a scientist. I thought Newton's theory was that gravity existed--not the how of it.
Newtons theory of universal gravitational attraction didn't just posit that gravity EXISTED, it gave a mathematical formula that can be utilized to observe and predict the universe.
Newton described an inherent property of matter manifesting as a force of attraction between matter related to their combined mass and distance between their respective centers of mass.
works fine, until you get to very great distances and masses and very very small distances and masses