On March 31, 1596, French philosopher, mathematician, and writer René Descartes was born. The Cartesian coordinate system is named after him, allowing reference to a point in space as a set of numbers, and allowing algebraic equations to be expressed as geometric shapes in a two-dimensional coordinate system. He is credited as the father of analytical geometry, the bridge between algebra and geometry, crucial to the discovery of infinitesimal calculus and analysis. Descartes was also one of the key figures in the Scientific Revolution and has been described as an example of genius. He has been dubbed the 'Father of Modern Philosophy'. His Meditations on First Philosophy continues to be a standard text at most university philosophy departments.
On March 21, 1768, French mathematician and physicist Jean Baptiste Joseph Baron de Fourier was born. He is probably best known for his work in thermodynamics, where he introduced the concept of the Fourier Analysis, named in honor after him. There, he claimed that every mathematical function of a variable can be expanded to a sum of sines of multiples of that variable. What people most likely don't know is that Fourier also was the first to describe the greenhouse effect, which is responsible also for global warming.