Changes

===Optics===

===Optics===

While waiting out the plague he began to investigate the nature of light. White light, according to the prevailing theories, was homogeneous. His first experiments with a prism provided the true explanation of color. Passing a beam of sunlight through a prism, he observed that the beam spread out into a colored band of light (spectrum). While others had undoubtedly performed similar experiments, it was Newton who showed that the differences in color were caused by differing degrees of refrangibility. A ray of violet light, for example, when passed through a refracting medium, was refracted through a greater angle than a ray of red light. His conclusions, checked by ingenious experiments, were that sunlight was a combination of all the colors and that the colors themselves were monochromatic (his term was "homogeneal"), and separated merely because they were of differing refrangibility.  

While waiting out the plague he began to investigate the nature of light. White light, according to the prevailing theories, was homogeneous. His first experiments with a prism provided the true explanation of color. Passing a beam of sunlight through a prism, he observed that the beam spread out into a colored band of light (spectrum). While others had undoubtedly performed similar experiments, it was Newton who showed that the differences in color were caused by differing degrees of refrangibility. A ray of violet light, for example, when passed through a refracting medium, was refracted through a greater angle than a ray of red light. His conclusions, checked by ingenious experiments, were that sunlight was a combination of all the colors and that the colors themselves were monochromatic (his term was "homogeneal"), and separated merely because they were of differing refrangibility.

== Gravity ==

== Gravity ==