## Newton's Experiments with Light and Optics

Newton wasn’t only fascinated by how motion and gravity worked. Rather, it was a puzzle that he had the mental capability to solve. Newton’s unparalleled capabilities and unfathomable intelligence enabled him to do what he loved most: understand how things worked. His unsustainable appetite for knowledge propelled him in his experiments. He was interested by all things, especially light. Newton discovered that white light is, in fact, made of all colors of light. He proved this with his prism experiments. He refracted a single beam of white light through a prism, and it produced a sort of rainbow effect. This is because different colors of light refract at different angles. But when he refracted the rainbow of colors, they reformed the beam of white light. Thus, he proved that a combination of all colors produce white light. This seemed impossible, because when you mix all colors of paint, you get black. Newton’s discovery of light is one way, however small, Newton flipped the world on its head. What’s more world-flipping than turning black into white? One might even say Newton took light apart, analyzed it, and put it back together the same way someone takes apart a machine and reassembles it. But why would Newton deconstruct light? He made these discoveries to satisfy his own need for knowledge.

Newton's experiments with optics

This excerpt from Newton's

"In like manner, if there be a Prism of Glass (that is, a Glass boundedwith two Equal and Parallel Triangular ends, and three plain and well polished Sides, which meet in three Parallel Lines running from the three Angles of one end to the three Angles of the other end) and if the Refraction of the Light in passing cross this Prism be desired: Let ACB [in _Fig._ 2.] represent a Plane cutting this Prism transversly to its three Parallel lines or edges there where the Light passeth through it, and let DE be the Ray incident upon the first side of the Prism AC where the Light goes into the Glass; and by putting the Proportion of the Sine of Incidence to the Sine of Refraction as 17 to 11 find EF the first refracted Ray. Then taking this Ray for the Incident Ray upon the second side of the Glass BC where the Light goes out, find the next refracted Ray FG by putting the Proportion of the Sine of Incidence to the Sine of Refraction as 11 to 17. For if the Sine of Incidence out of Air into Glass be to the Sine of Refraction as 17 to 11, the Sine of Incidence out of Glass into Air must on the contrary be to the Sine of Refraction as 11 to 17, by the third Axiom."

―Isaac Newton, Excerpt from

To read more of Newton's

*Opticks*describes how rays of light are refracted through a prism."In like manner, if there be a Prism of Glass (that is, a Glass boundedwith two Equal and Parallel Triangular ends, and three plain and well polished Sides, which meet in three Parallel Lines running from the three Angles of one end to the three Angles of the other end) and if the Refraction of the Light in passing cross this Prism be desired: Let ACB [in _Fig._ 2.] represent a Plane cutting this Prism transversly to its three Parallel lines or edges there where the Light passeth through it, and let DE be the Ray incident upon the first side of the Prism AC where the Light goes into the Glass; and by putting the Proportion of the Sine of Incidence to the Sine of Refraction as 17 to 11 find EF the first refracted Ray. Then taking this Ray for the Incident Ray upon the second side of the Glass BC where the Light goes out, find the next refracted Ray FG by putting the Proportion of the Sine of Incidence to the Sine of Refraction as 11 to 17. For if the Sine of Incidence out of Air into Glass be to the Sine of Refraction as 17 to 11, the Sine of Incidence out of Glass into Air must on the contrary be to the Sine of Refraction as 11 to 17, by the third Axiom."

―Isaac Newton, Excerpt from

*Opticks*To read more of Newton's

*Opticks*, click here.