# Historical Astronomers in Context: Isaac Newton

Isaac Newton (December 25, 1642 – March 20, 1727) spent some time working on gravitation and how it affects the orbits of planets. He eventually published the Principia Mathematica, which introduced Newton’s law of universal gravitation, i.e. $F=G\frac{m_{1}m_{2}}{r^{2}}$

In September 1666, when Newton was 23 and attending Trinity College, Cambridge (in England), the Great Fire of London occurred. This enormous fire burned down basically the entire medieval City of London, destroying about 70,000 homes. In 1692, while Newton was starting the later years of his life and writing religious tracts, the Salem witch trials began in Massachusetts. The Salem witch trials are one of America’s most famous historical examples of mass hysteria, and in the most famous trial, 20 people were hanged after being accused of being witches.

King Charles I of England, Scotland, and Ireland was alive from November 19, 1600 – January 30, 1649. He was beheaded after being convicted of treason after losing the English Civil War. After his death, royalists viewed the King as a martyr, but England became a Commonwealth nonetheless.

Often, history is taught as separate events, and while some context is usually given, it is generally taught separately as scientific history, political history, etc. To see that monarchies were finally going out of style as Newton’s life started, but that such a fanatical sort of event like the Salem witch trials were happening still at the end of his life, is really eye-opening—Newton didn’t make his discoveries in a vacuum, but was in fact greatly affected by everything that went on in the world around him, especially in Europe.