Christiaan Huygens (1629-1695) worked out a mathematical wave principle of light in 1678, and posted it in his Treatise on light in 1690. He proposed that light was emitted in all directions like a number of waves in the medium called the Luminiferous ether. As waves usually are not https://kameronxfnud.blogofoto.com/70317174/the-2-minute-rule-for-light-gauge-steel-framing