JFSanders – Ponder this, if you are on that train going 0.999999…c (almost the speed of light, but not quite) and your turn on the headlight, what happens? What if you are standing some distance from the track, at rest, can see the train, do you see the headlight come on?

A frame of reference is any place that you can place yourself. Including a crystalline lattice. And yes, it does travel through different mediums at different speeds. That ‘frame of reference’ thing again.

And the speed of light is absolute. It is always c, in all frames of reference.

And E = gamma times m times c ^ 2. Gamma is the fudge factor for frames of reference, sorta.

gamma = 1/(1-(v^2/c^2)) and is greater than or equal to 1. (Sorry, I don’t have the symbolic library) v is your speed in your frame of reference.

To ponder those sort of questions and others is the best we can be. Whether it is relativistic mechanics or the relations of the elites to their suborned ones. (To have an elite class there MUST be peasants, yes?) I forget where I saw it but there was a thread that simply said there are two types of humans. Doers and not-doers. The not-doers can only exist as parasites on the doers. IOW, government/rulers/elites produce no thing.