Let There Be Light Waves

             When philosophers talk about light and waves and particles they all stood in the shadow of the great Sir Isaac Newton even tho theories on light being either a wave or particles go as far back as to the ancient Greeks. Newton however, favored the particle theory, which Mr. Young was not entirely convinced about. He read Newtons books in 1790 when he was only 17 years old. He had finally started his own investigations 7 years later in 1797. In newtons corpuscular Theory, light  was imagined to be a stream of minute particles, called corpuscles, emitted by a light source shooting through empty space like bullets and only detected when they struck the retina. He didn't go with the wave theory because he figured when light is blocked by an object the light is no longer visible to anyone in the path of the object unlike sound waves when two people behind a closed door with no visibility of each other can still hear each other, that's because sound waves bend and light doesn't therefore no light could be in waves.
              Another theory (not done by Newton but by Huygen) is that, when a light ray strikes a flat reflecting surface, such as a mirror, the angle of incidence is equal to the angle of reflection. With the law of reflection also comes the opposite. Refraction also know as, Snell's Law! This states that when light waves stike the surface of water and pass through it, the angle of incidence is different than the angle of refraction. The angle of refraction is less than the angle of incidence and the light ray is then bent toward the normal, perpendicular line. However, in Newtons day this was not all to convincing because there needed to be more physical evidence but Newton did a terrible job in trying to prove it, but Huygen on the other hand did a wonderful job. He stated that light travels slower in water than in air and he used the wave theory to prove Snell's law. Therefor disproving the Corpuscular theory.

In the early 1800's Young goes on to write and study light waves and the relation to sound waves, and he discusses them in his paper  " Sound and Light" which was read to the royal society in January of 1800.