The nature of light.
A photon has has energy and momentum (weight) but no mass . It is obvious that light is vibrations of some medium (ether). This environment cannot but have resistance, damping or absorbing light vibrations with time and distance. I will describe the essence in simple words so as not to complicate and not drag out the explanation.
1) Water waves.
They spread longer (in time) than sound, but at a shorter distance (at a lower speed). Distribution medium: water.
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