Jean-Baptiste Joseph Fourier was born on March 21, 1768 in Auxerre, France. When he became an orphan at age 9, the Benedictine Order of the Convent of St. Mark housed and educated him. By the time he reached adulthood, he was employed by the military to teach mathematics.
His support of the French Revolution resulted in his brief incarceration during the Reign of Terror, but in 1795, after the Revolution, his mathematical prowess earned him an appointment to the École Normale (teacher’s college) and eventually the prestigious École Polytechnique where he succeeded Joseph-Louis Lagrange.
In 1798, Fourier served as the scientific advisor to Napoleon Bonaparte during the Egyptian expedition and was appointed secretary of the Egyptian Institute that Napoleon had established to bring a French influence to that part of the world. After the British took control of Egypt, Fourier returned to his position at the École Polytechnique and in 1801 was appointed by Napoleon to the position of Governor of the Department of Isère in Grenoble. One of his duties in Grenoble was to oversee the draining of the swamps of Bourgoin and to supervise the construction of a new highway from Grenoble to Turin.
During his time at Grenoble, Fourier explored the propagation of heat and this research resulted in his publication in 1807 of his famous paper, On the Propagation of Heat in Solid Bodies. Fourier asserted that any function of a variable, can be expanded in a series of sines and cosines of multiples of that variable. Though this theorem requires additional constraints on the functions, Fourier’s observation that some discontinuous functions are the sum of an infinite series trigonometric functions was a significant contribution to mathematics, and determining the conditions for convergence of such series became a major focus of mathematical investigation, leading eventually to the development of what is known as the Fourier transform.
On May 16, 1830, Joseph Fourier, at the age of 62, died of something that was assumed to be heart failure, following a serious fall down a flight of stairs. Though his life was encumbered with a turbulent political environment, his intellectual insights prevailed and he was able to make significant contributions to mathematics that remain important to this day.
