I was wondering if you could elaborate on what the strong force is. Is it an attraction among nuclear particles, like the EM force is an attraction amoung charged particles?
The strong force actually has some weird properties, and a full exploration of its nature is beyond the scope of this course. It’s an attraction between quarks, which make up nuclear particles (nucleons) like protons and neutrons. Quarks are bound inside nucleons. Quarks are always found in bound states, because the strong force binding them has the strange property that, unlike electromagnetic and gravitational forces, the attractive force gets stronger as the separation between the quarks increases. You have to put in infinite energy to separate quarks to infinity; hence, free quarks can not exist. The attraction between nucleons is not a “direct” strong force attraction, but rather can be thought of as a kind of “residual” quark force, in the same way that the van der Waals attraction between molecules is a residual electrostatic force. The attraction between nucleons kicks in only at very short range. The strong force is also known as the “color force”, and the theory describ
