In the late 19th century, luminiferous aether or ether, meaning light-bearing aether, was the term used to describe a medium for the propagation of light.[1]
Due to the negative outcome of aether-drift experiments like the Michelson-Morley experiment, the aether as a mechanical medium having a state of motion, is not used anymore in modern physics, and is replaced by the theory of relativity and quantum theory.