The square–cube law was first described by an astronomer born in what year?
Galileo Galilei Galileo Galilei (] ; 15 February 1564 – 8 January 1642) was an Italian polymath: astronomer, physicist, engineer, philosopher, and mathematician. He has been called the "father of observational astronomy", the "father of modern physics", the "father of the scientific method", and the "father of science". Galileo studied speed and velocity, gravity and free fall, the principle of relativity, inertia, projectile motion and also worked in applied science and technology, describing the properties of pendulums and "hydrostatic balances", inventing the thermoscope and various military compasses, and using the telescope (a Dutch optical instrument) for scientific observations of celestial objects.
Patrick d'Arcy Patrick d'Arcy (27 September 1725 – 18 October 1779) was born in the west of Ireland. His family, who were Catholics, suffered under the penal laws. In 1739 d'Arcy was sent abroad by his parents to an uncle in Paris. He was tutored in mathematics by Jean-Baptiste Clairaut, and became a friend of Jean-Baptiste's son, Alexis-Claude Clairaut, (Alexis Clairaut), who was a brilliant young mathematician. d'Arcy made original contributions to dynamics. He is best known for his part in the discovery of the principle of angular momentum, in a form which was known as "the principle of areas," which he announced in 1746. See the article on areal velocity. d'Arcy also had an illustrious military career in the French army. He obtained the title of "Count" in the French nobility. He was a generous patron of Irish refugees in France. In addition to his contributions to dynamics, he performed research on artillery and on electricity. An experiment of his, reported in 1765, on visual perception is often referred to: it involved a rotating disk on which a burning coal was placed; when the disk was spun at an angular velocity exceeding seven revolutions per second, a full circle of light was perceived. This and other experiments makes d'Arcy the first person to demonstrate the illusion of a moving image; although Joseph Plateau greatly elaborated on this initial finding. d'Arcy was elected to the Academie Royale des Sciences in 1749. He died from cholera in Paris in October 1779.