What Goes On in a Proton? Quark Math Still Needs Answers
https://www.wired.com/story/what-goes-on-in-a-proton-quark-math-still-needs-answers/
Objects are made of atoms, and atoms are likewise the sum of their parts—electrons, protons, and neutrons. Dive into one of those protons or neutrons, however, and things get weird. Three particles called quarks ricochet back and forth at nearly the speed of light, snapped back by interconnected strings of particles called gluons. Bizarrely, the proton’s mass must somehow arise from the energy of the stretchy gluon strings, since quarks weigh very little and gluons nothing at all.
Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.