On the difference of radio waves from the sound vibrations in the air
Light and sound — that is what from time immemorial people imagined like something flying or self-spreading. Following the ancient scholars, in the Renaissance they believed that the space is filled with a gas-like substance called aether, in which the light propagates as a sound in the air. It was already known that the light and radio waves are of the same nature when the radio broadcast came into the world, but the aether was not detected and its properties remained unclear. At the beginning of the XIX century, experiments of Young and Fresnel finally confirmed the wave nature of light, and faith in the aether had strengthened. However, these experiments suggest that light waves are transverse, as they would look in a solid rather than a gaseous medium. Half a century later, Maxwell formulated the laws of propagation of electromagnetic waves, and it turned out that these are not tied to the nature of the aether. At the end of the century they were aggressively searching for the aether, but the appearance of the theory of relativity has made this concept unnecessary.