What Is the Quark Model?

Hadrons began being discovered in the 1930s. At first, it was just a dribble. But then as people built accelerators to examine things more systematically, it rapidly blossomed into tens and then hundreds of unstable hadrons. It's not really essential to go beyond protons and neutrons for advanced subjects like cosmology or high energy physics. The next big thing that helped clarify it was called the quark model.