I'll try to keep this short and to the point. This is all just theory. Obviously, very little of it has been properly tested via experimentation. I hope that changes in the future.
Waves are mechanical. They have to have a medium for propagation, so light (being a wave) must have travel through a medium. If there is no medium, there is no wave, and therefore no light. Space-time cannot be a medium. Space has no attributes. It is simply another word for volume. There is no reason to believe that time is malleable, so the notion of space-time as a medium simply does not work. There has to be an aether. You can call it whatever you like, quantum vacuum, virtual particles, condensate,...whatever, but there must be some kind of aether to act as a medium. Every medium has its own rate of induction depending on its ratio of bulk modulus (stiffness) to density. Therefore, the rate of induction for light in an atmospheric vacuum is a constant within our universe.
A photon is a single electromagnetic wave. It is a transverse magnetic perturbation of the aether, which results in the electric longitudinal compression and rarefaction of the aether. One magnetic pole causes compression, while the other causes rarefaction. Transverse compression and rarefaction reflects the literal spin of the magnetic field, while the longitudinal compression and rarefaction reflects the pressure fluctuation of the field. While these two actions are really one in the same, we call the transverse surface wave, MAGNETISM, and the longitudinal pressure wave ELECTRICITY. The existence of both positive and negative charge pressures within a single photon (EM wave) means that photons are dielectric (electric neutrality).
Magnetic fields have literal spins, therefore photons, electrons, and positrons have spins. The spin of a toroidal magnetic field is the result of many smaller toroidal magnetic fields flowing through the magnetic vortex. The pathways of these smaller toroids make up the field lines of the larger magnetic field. This is an incommensurable fractal model that probably encompasses infinite scales. The spin of a photon is 1 integer, while the spins of electrons and positrons are 1/2 integer. Spin-1 means that the particle must complete one full revolution to return to its initial state. Spin-1/2 means that the particle only needs 1/2 of a revolution to return to its initial state. This seems counter intuitive, but remember that magnetic field lines each have rivers of smaller spinning fields.
[This video demonstrates how earth's magnetic field lines are energized with plasma tubes. Plasma is a flow of ionized gas. Flowing ions create electric fields coupled with spinning magnetic fields per the right hand rule of electricity.]
In the case of 1 integer spins, the particle's magnetic field is spinning in one direction, while the internal field lines are spinning in the opposite direction. This means that the angular momentum of a photon is, to a degree, self cancelling. Its like hanging a gyroscope from a string, and swinging it clockwise while the flywheel is spinning counter clockwise. The cancelling spins will cause the gyroscope to lose relative mass. This is why photons are said to be massless. There is no such thing as zero mass. There is only inertial mass (rest mass), and relative mass, created by momentum and resistance. Therefore, a photon must complete one whole revolution to negate the effects of its internal field line counter spins, in order to return to its initial state. Another way to say this, is that the overall angular momentum within a photon is incoherent (destructive interference).
In the case of 1/2 integer spins, the spin of the particle's magnetic field is in the same direction as the spins of its field lines. Now just imagine swinging a gyroscope in a clockwise motion while the flywheel is also spinning clockwise. This means that the overall angular momentum of the particle is coherent (constructive interference), causing the particle to gain relative mass while only having to make 1/2 a revolution to return to its initial state. This is how positrons and electrons can both have mass, while photons are assumed massless.
One of the biggest road blocks in Quantum Mechanics is the spin in relation to the magnetic fields of charged particles. For example, an electron would have to spin much faster than the speed of light in order to generate the magnetic fields they carry. It would be impossible for an electron to do that, let alone to have it spin at the speed of light. However, if the spinning energy of the electron's magnetic field lines is coming from a higher energy aether, then it would have an induction rate much faster than the speed of light. Therefore, no violation of the speed of light within our universe.
If magnetic field lines are just rivers of smaller magnetic fields, then those smaller magnetic fields must work the same way. This is what I mean by incommensurable fractals. This implies that there must be a higher energy aether that generates the field perturbation within our own aether, which we call electromagnetism. That higher energy aether would have a much faster induction rate than our own light speed constant. This could account for quantum entanglement. Electron-positron pairs are born in entangled states when two gamma photons collide. If one particle is spin-up, then the other particle is spin-down. If one particle's spin orientation is changed, then so will the other particle's orientation instantaneously change, regardless of distance. This violates the universal speed limit of light. The only other explanation I can think of is that these particles are not entangled within our own aether field, but in a higher aether field that simply does not occupy our spatial dimensions. The induction rate of that higher aether field would appear instantaneous to us, relative to our (much slower) light speed induction rate. If we can find a way to detect both the existence of our aether, and of a higher energy aether, we might be able to prove the existence of parallel universes.
So far, this theory has been able to intuitively explain magnetism, electric charge, angular momentum (spin), relative mass, and quantum entanglement. Of course this would have to be tested both mathematically and experimentally, neither of which can I do at this point.
I did come up with a few simple equations for mass and momentum.
I = Inertia/Inertial Mass/Rest Mass/Resistance, R = Relative Mass, M = Momentum
R = MI
The closest thing to true inertial mass in this universe is the mass of our dielectric aether at rest. We don't know how to measure that, so its simply deemed non-zero. Photons are not massless. They have self cancelling mass, which brings it back down to the inertial mass of the dielectric aether at rest. All other mass in this universe is relative. Your mass on earth is not the same as your mass on the moon. Therefore, relative mass is momentum resisting inertia. Its like the momentum of your fist meeting the inertia of water when you try to punch in the bottom of a pool.
I = -M + M
This is basically Newton's law restated. A force met with an equally opposite force results in inertia. Therefore, negative momentum and positive momentum cancel resulting in inertia. The same can be said for the self cancelling angular momentum of photons.
The word of God is alive and powerful, sharper than any two-edged sword, piercing even to the dividing asunder of the soul and the spirit, of the joints and marrow, and is a critic of the thoughts and intents of the heart.