William Herschel
British astronomer Sir William Herschel, brother of British astronomer Caroline Herschel, discovered Uranus in 1781, cataloged more than eight hundred double stars and 2.4 thousand previously unknown nebulae and other deep-sky objects, and fathered British astronomer John Frederick William Herschel.
This technical expert and composer followed his father into the military band of Hanover before migrating to Great Britain at the age of 19 years in 1757. He famously discovered the planet alongside Titania and Oberon of its major moons and also discovered two moons of Saturn. In addition, he first personally discovered the existence of infrared radiation. People also know him for the 24 symphonies and many other musical pieces that he composed.
Music led Herschel to an interest in mathematics and lenses. Making the acquaintance of the English astronomer royal Nevil Maskelyne afterward strengthened his interest in astronomy. He started building his own reflecting telescopes and would spend up to 16 hours a day grinding and polishing the speculum metal primary mirrors. He "began to look at the planets and the stars" in May 1773 and on 1 March 1774 began an astronomical journal by noting his observations of Saturn's rings and the Great Orion Nebula (M 42).
On 11 February 1800, Herschel was testing filters for the sun so he could observe sun spots. When using a red filter he found there was a lot of heat produced. Herschel discovered infrared radiation in sunlight by passing it through a prism and holding a thermometer just beyond the red end of the visible spectrum. This thermometer was meant to be a control to measure the ambient air temperature in the room. He was shocked when it showed a higher temperature than the visible spectrum. Further experimentation led to Herschel's conclusion that there must be an invisible form of light beyond the visible spectrum.
Herschel used a microscope to establish that coral was not a plant, as many believed at the time, since it lacked the cell walls characteristic of plants.
“By reflecting a little on this subject I am almost convinced that those numberless small Circuses we see on the moon are the works of the Lunarians and may be called their Towns.”