Christiaan Huygens and the Wave Theory of Light

Dutch scientist Christiaan Huygens proposed in 1678 that light travels as a wave.
His theory challenged Newton’s idea that light was made of tiny particles, or “corpuscles.”
Huygens suggested light waves spread outward in all directions, like ripples in water.
He introduced the Huygens’ Principle, where every point on a wavefront acts as a new source of waves.
This principle explained reflection and refraction more clearly than Newton’s model.
Huygens also showed how light bends when entering glass or water, predicting its slower speed there.
His wave theory set the stage for later proofs of interference and diffraction.
In the 19th century, Young’s double-slit experiment confirmed Huygens’ wave ideas.
Huygens wasn’t only a physicist—he also invented the pendulum clock and studied Saturn’s rings.
His insights helped shift physics toward understanding light as both wave and, later, particle.