One of the various theories proposed to explain the negative result of the famous Michelson-Morley experiment with light waves (conceived to measure the absolute space), was based on the ballistic hypothesis, i.e. on postulating that the speed of light predicted by Maxwell's equations was not given as relative to the medium but as relative to the transmitter (firearm). Had that been the case, the experiment negative results would have not caused such perplexity and frustration (as we shall see in forthcoming sections).