Instinct, and my limited knowledge of Maxwell's Equations and the Wave Equation tell me that the first statement is true.
By my interpretation, the relationship between the frequencies and wavelengths of e.m. waves (and hence the speed of light) is dictated
by the relationship between electric and magnetic fields, which is in turn dictated by Vacuum Permittivity, which I believe (possibly in error)
to be an inherent property of our universe.
Is this right, or is the speed of light somehow dictating Vacuum Permittivity?
Or have I got something totally wrong?
Best Answer
At first sight, I understand that it might be plausible that permeability and permittivity seem to be fundamental constants of spacetime which are together forming the constant of speed of light.
However, the speed of light is the more fundamental parameter. The speed of light c is not limited to electromagnetic waves, it is equally the speed of gravitational waves which are not at all electromagnetic. Thus it is easy to see that $c$ is more fundamental than $ε_0$ and $µ_0$.
For an intuitive model you can think of EM waves as only one form among others for the propagation at the universal speed limit, however with the particularity that they are based on two kinds of forces so that the speed limit has to be distributed among two kinds of forces (electric and magnetic), giving $ε_0$ and $µ_0$.