If one end of a string is moved up and down, a wave travels along it. Similarly a medium is required to transfer a sound wave from one point to other point. Sound is produced due to the compression and rarefaction of the particles of the medium. So, sound waves need a medium for their propagation and this medium can be air, liquid and solid.
According to classical theory of light, light waves require a medium for their propagation. This medium is called ether. But Michelson and Morley did perform an experiment and proved that ether does not exist. It means no medium is required for the light wave to travel. Moreover, classical physics does not agree with the concept of Morley and Michelson.
According to classical theory of light, light waves require a medium for their propagation. This medium is called ether. But Michelson and Morley did perform an experiment and proved that ether does not exist. It means no medium is required for the light wave to travel. Moreover, classical physics does not agree with the concept of Morley and Michelson.