I'm quite new to the physics world and want to get an idea as to how physicists have been able to sum all fields/forces (higgs boson, electromagnetic, weak force, strong force etc) in a said object, and determine that this summation is equal to the object's gravitational field.
From what I've heard, I have understood that you can calculate (through mass-energy equivalence) these individual forces' mass counterpart and some how summate them to determine the "net" mass - which is somehow related to the gravitational "field" of said object. Now, I know this makes no sense to me, especially considering that gravity is the weakest of the forces (how can all forces summated give the weakest one?) and how these calculations/conclusions be made. Anyone who can link me to an article concerning this, or has an explanation, thank you very much.