Marshall McLuhan
McLuhan pointed to the light bulb as an example. A light bulb does not have content in the way that a newspaper has articles or a television has programs, but it is a medium that has a social effect. The light bulb lets people do things at nightime which would be impossible in darkness. He describes the light bulb as a medium without any content. McLuhan states that "a light bulb creates an environment by its mere presence". He then goes on to compare the effects of radio, television and film (movis).