From Today in Science History:
British physicist who demonstrated why the sky is blue. His initial scientific reputation was based on a study of diamagnetism. He carried out research on radiant heat, studied spontaneous generation and the germ theory of disease, glacier motion, sound, the diffusion of light in the atmosphere and a host of related topics. He showed that ozone was an oxygen cluster rather than a hydrogen compound, and invented the firemans respirator and made other less well-known inventions including better fog-horns. One of his most important inventions, the light pipe, has led to the development of fibre optics. The modern light instrument is known as the gastroscope, which enables internal observations of a patient’s stomach without surgery. Tyndall was a very popular lecturer.