  The c-equivalence principle, commonly accepted as true by most physicists, is
the unstated assumption that $1/\sqrt{\epsilon_o \mu_o}$ equals the kinematic
speed of light. Should someone prove the principle false, it would render the
composition of two Lorentz transformations meaningless. It would also
invalidate the second hypothesis of the Special Theory of Relativity in its
strong form. This paper examine some other consequences for physics, should
this principle be proven false and outline some experiments to determine light
speed, which could falsify the principle and provide evidence for the ether.
