The concept of the "internal speed of light" inside quarks is not applicable within our current understanding of physics. Quarks are elementary particles that are considered to be point-like and do not have internal structure in the classical sense.
The speed of light, denoted by 'c,' is a fundamental constant in physics that represents the maximum speed at which information or causality can propagate through spacetime. It is a constant that applies universally and is independent of the specific properties of particles or their internal dynamics.
Quarks are governed by the laws of quantum chromodynamics (QCD), which describes the interactions of quarks and the strong nuclear force. Within the framework of QCD, quarks are confined within composite particles called hadrons (such as protons and neutrons), and they cannot exist as isolated free particles. The strong force between quarks is mediated by particles called gluons, which also travel at the speed of light.
However, discussing the "internal speed of light" within a quark would imply that quarks have substructure or internal dynamics that can be described in terms of relativistic velocities. At present, there is no evidence or theoretical framework that supports such a concept for quarks.
Therefore, it is not meaningful to assign an internal speed of light to quarks within our current understanding of particle physics.