Final answer:
Theoretical models and indirect experimental observations support that the gluon force is greater than the strong nuclear force between hadrons, with gluons carrying color charge and being responsible for quark confinement within hadrons.
Step-by-step explanation:
The evidence supporting the contention that the gluon force between quarks is greater than the strong nuclear force (also known as the strong force) between hadrons comes from theoretical models and indirect experimental observations. The strong nuclear interactions, governed by quantum chromodynamics (QCD), show that quarks are bound together by exchanging gluons. Gluons carry a property known as color charge, which is not an actual color but a way to describe the different types of strong charge that quarks can have, labeled as red, blue, or green for convenience. Quarks combine in such a way to form color-neutral particles, meaning that the combination of their color charges results in 'white' or no net color charge.
Additionally, gluons themselves carry color charge and can change the color of a quark when they are exchanged during interactions. When high-energy electrons are scattered from nucleons, evidence suggests that quarks have smaller momenta due to the presence of gluons. This implies that gluons, which are the carriers of the strong force and have spin 1 and are massless, are indeed responsible for a significant portion of the force inside nucleons, as they also carry momentum.
Importantly, the idea of quark confinement in QCD posits that quarks and gluons cannot exist freely apart from each other. They are always confined within hadrons due to the incredibly strong gluon force at short distances. This property of gluons and the strong force ensures that quarks always pair up or group together in a way that renders them 'colorless' to the outside world, thus not allowing them to be isolated.