Wave Propagation in an Elastic Medium
The Ghost of the Luminiferous Ether
Before Einstein's 1905 revolution, physicists believed light waves must propagate through a medium—just as sound requires air and water waves require water. They called this invisible, all-pervasive medium the luminiferous ether.
What you're seeing is an idealized model of this ether: a lattice of spring-connected nodes. Click anywhere to introduce a disturbance and watch transverse waves ripple outward. This visualizes the elastic solid theory of the ether—a model seriously developed by physicists like Augustin-Jean Fresnel and Lord Kelvin. While James Clerk Maxwell and others entertained more complex mechanical models (like molecular vortices), this 2D system illustrates the fundamental intuition: that light could be a transverse wave propagating through an all-pervasive material medium.
A Medium That Never Was
The Michelson-Morley experiment of 1887 failed to detect the expected "ether wind," but at the time it was seen as a puzzling anomaly, not a decisive refutation. Physicists like Lorentz and FitzGerald proposed modifications—such as length contraction—to preserve the ether hypothesis. It was only through a gradual accumulation of theoretical insights that the concept of a mechanical ether was abandoned. Einstein's 1905 special relativity didn't so much disprove the ether as render it unnecessary: the electromagnetic field could be treated as a fundamental entity in its own right, requiring no underlying medium.
What the Model Shows
Each node is connected to its neighbors by virtual springs. Displacement at one point creates forces that pull neighboring nodes, propagating the disturbance outward. At 0% speed, the lattice freezes—clicks create permanent deformations that persist until you increase the wave speed.
∿ The ether is dead; long live the wave