I cam across this statement in Wikipedia: Note that the mass of a hadron has very little to do with the mass of its valence quarks; rather, due to mass–energy equivalence, most of the mass comes from the large amount of energy associated with the strong interaction. I find it somewhat disturbing and profound, if true. It seems to me that most of the time, we think of matter as having gravity as one of its properties. But the quoted text says that most of the mass of hadrons is produced not by the rest mass of the constituent quarks (i.e., the matter), but instead by the energy associated with the strong interaction holding that matter in proximity. Is most of the gravity we are aware of in the universe produced by the energy associated with the strong force? What are the proportions? How much gravity can be attributed to rest mass, and how much to the strong force?