Interpreting Newton’s Laws — Louis Poinsot

Louis Poinsot interpreted Newton’s laws of motion to lay the foundations for modern engineering analysis. Isaac Newton revolutionized science in 1687 when he presented to the world his three laws of motion and his theory of gravitation. Newton elevated mathematics as an indispensable tool in a rational approach to describing the mechanics that underlie the physical world. Newton’s elucidation of the laws of nature sparked the period of the Enlightenment during the 18th century and its quest to reform society by the rational application of natural law.

However, Newton could only do so much. His insights were directed primarily to understanding the mechanics of celestial spheres, astronomy. Advances in the practical mechanics of buildings and machines were left for others who followed Newton’s lead. Therefore, the development of the field of mechanics, hydromechanics, thermodynamics, and electrodynamics became the focus for a generation of mathematicians in France inspired by the French Revolution.

Poinsot was among the most brilliant of this generation. Originally intent on a career as an engineer, Poinsot was drawn to the more abstract challenges offered by applied mathematics. In 1803, at the early age of 26, Poinsot compiled his famous book, Elements of Statics. Poinsot also derived, from geometric arguments alone, a description of the complex and counter intuitive behavior of freely rotating bodies. Poinsot intended his book initially as a guide for students studying to enter the Ecole Polytechnique, however it touched on problems significant enough to gain the attention of the Academy of Science. A first-year course in statics is still today a student’s introduction to mathematical analysis in engineering.

Louis Poinsot is one of the 72 engineers and scientists named on the Eiffel Tower.