Why the Speed of Light Can Be Independent of Translation of Source-Receiver

To see that it is most natural that the speed of light between a source and receiver is independent of translation with constant velocity of both source and receiver, as if the "aether" was moving along with the same velocity, consider the following mechanical analog: 

Connect a source to a receiver by waves carried by a stretched rope with the source at one end and the receiver at the other end, and assume that the whole system source-rope-receiver is subject to a translation with constant velocity. We would then make the observation that the speed of propagation of the waves from source to receiver through the rope would be independent of the translation. 

This is because the rope as the medium for wave propagation moves along with the source/receiver. The analog would be an "aether" as an immaterial medium for propagation of light waves, which moves along with the source/receiver. The idea is that the light source and receiver establishes a connection like a rope which is moving along with the source/receiver.  This would be compatible with the null result of the Michelson-Morely experiment.

There is thus no common background aether, but a multitude of aethers connecting and moving along with a multitude of sources/receivers.  The immaterial quality of aethers would then allow a multitude without conflict. This is the idea of Many-Minds Relativity. Think of that.

PS If the source and receiver move with respect to each other they could still share a common aether (connected to either source or receiver) with still  he same speed of light, while light frequencies would be subject to Doppler effects.