Hi Dirayankar; One Einstein said it wasn't needed, later rethought his idea and concluded there was a form of ether, throughout space. Be it gravitational waves, electromagnetic fields, etc.
"We assume to find in every point of space a flow in all directions of radiant energy from all astrophysical objects, meaning that space everywhere has a specific energy
U [erg] and an energy density
u = U/V [erg/cm³], which of course is a local variable depending on the position in space".
"The radiant energy will we name the "Aether", and since it is present throughout the Universe, we will call space the "Aether-Space". Presuming the aether the medium sustaining all physical fields and forces, the aether-space is the
universal physical space".
Best to all, Pat P.S. Drifter my Bhagavad-Gita was published by The Bhaktivedanta Book Trust