Calculus is a branch of mathematics that explores variables and how they change by looking at them in infinitely small pieces called infinitesimals. Calculus, as it is practiced today, was invented in the 17th century by British scientist Isaac Newton and German scientist Gottfried Leibnitz. They independently developed the principles of calculus in the traditions of geometry and symbolic mathematics.

While these two discoveries are most important to calculus as it is practiced today, they were not isolated incidents. At least two others are known: Archimedes (287 to 212 B.C.) in Ancient Greece and Bhāskara II (A.D. 1114 to 1185) in medieval India developed calculus ideas long before the 17th century. Tragically, the revolutionary nature of these discoveries either wasn’t recognized or was so buried in other new and difficult-to-understand ideas that they were nearly forgotten until modern times.