1595-1667

Bohemian physicist who anticipated by two decades many of the observations on optics made by Sir Isaac Newton (1642-1727). Sometimes called simply Marcus Marci, Johannes served as professor and rector of Prague's Charles University, where in 1648 he published Thaumantias liber de arcu coelesti.... In it, he discussed the colors of the rainbow, the dispersion of light beams directed through a prism, and the diffraction of light around a wire. He also observed that repeated refraction does not cause monochromatic rays to change color. In addition to his work in optics, Johannes performed a number of experiments in mechanics using a pendulum.