Christiaan Huygens (1629-1695) worked out a mathematical wave principle of light in 1678, and published it in his Treatise on light in 1690. He proposed that light was emitted in all directions like a number of waves inside of a medium called the Luminiferous ether. As waves usually are https://modular-house11098.activablog.com/38022762/the-ultimate-guide-to-folding-container-house