Étienne-Louis Malus

Étienne-Louis Malus, born on July twenty-third, seventeen seventy-five in Paris, France, was a distinguished French officer, engineer, physicist, and mathematician. He pursued his education at the military engineering school in Mezires, where he was influenced by the teachings of Gaspard Monge. His career was marked by his participation in Napoleon's expedition to Egypt from seventeen ninety-eight to eighteen oh-one, during which he also became a member of the mathematics section of the Institut d'Égypte.

In eighteen ten, Malus was honored with membership in the Académie des Sciences and received the prestigious Rumford Medal from the Royal Society of London. His contributions to mathematics were primarily focused on the study of light, where he explored geometric systems known as ray systems, closely related to Julius Plücker's line geometry. His groundbreaking work included experiments that verified Christiaan Huygens's theories of light, which he reformulated in an analytical context.

Malus is perhaps best known for his discovery of the polarization of light by reflection, published in eighteen oh-nine, and his theory of double refraction in crystals, presented in eighteen ten. He sought to establish a connection between the polarizing angle of reflection he discovered and the refractive index of various materials. Although he successfully deduced the correct relationship for water, he faced challenges with glass due to the inferior quality of materials available at the time.

His legacy includes Malus's law, which describes the resultant intensity when a polarizer is placed in the path of an incident beam. A follower of Laplace, Malus formulated his theories on polarization and birefringence using the corpuscular theory of light. His name is immortalized among the seventy-two names inscribed on the Eiffel Tower.

Despite his remarkable achievements, Malus struggled with poor health, partly due to illnesses contracted during his time in Egypt. By eighteen twelve, his battle with tuberculosis had progressed, leading to his untimely death in Paris at the age of thirty-six.