> By aether, do you mean an underlying medium that allows forces to be propagated? I guess that using that definition, there is an 'aether'. That's what an 'ae

> By aether, do you mean an underlying medium that allows forces to be propagated? I guess that using that definition, there is an 'aether'. That's what an 'aether' is -- that background medium which the interaction is happening within. My conception of it is that Michelson-Morley disproved an infinitely rigid aether, which was the conception at the time and squared with Newtonian physics because it's equivalent to an infinite speed of information. Einstein then corrected the aether models to account for the finite speed of information through the aether, and the impacts that aether waves have on causality. My impression has always been that dropping 'aether' was merely a branding move, rather than anything technical about the term. (Not that I fault scientists for this, it's politically savvy -- but it's weird to see their marketing used as arguments decades later.)