From Luminiferous Ether to the Earth’s Motion

This chapter aims to recall the circumstances in which the etherEther was introduced into physics. We will see that by filling the vacuum with ether, Aristotle made it the material support or interstellar medium necessary for the motion of planets in spaceInterstellar space. A few centuries later, Newton was thus able to explain the transmission of gravitational forces that he had just discovered. If the Earth’s motion around the Sun was then totally accepted by all scholars, some nevertheless sought to highlight it. It was during this period that MaxwellMaxwell, James Clerk demonstrated that light was an electromagnetic wave propagating both in air and in a vacuum, that is to say, in ether. It was then sought to measure the speed of light relative to the Earth moving in ether and thus demonstrate the Earth’s motion around the Sun. Unfortunately, all experiments failed. Thus, it was as if the Earth was at rest in the Universe.