Louis Victor Pierre Raymond de Broglie, a twentieth century French theoretical physicist, established the foundations for wave mechanics, and as a result for much of modern physics. The principle underlying wave mechanics is that matter has both the characteristics of particles and waves, and the particular characteristic that is observed will depend on how the observation is made. These ideas fundamentally changed the way physicists view the world, and earned Louis de Broglie the 1929 Nobel Prize for physics.

Louis de Broglie was the youngest of five children. His early education was obtained at home. Born to Duc Victor and Pauline d'Armaille Broglie on August 15, 1892 in Dieppe, France, the young physicist-to-be was second in line to his elder (by 17 years) brother Maurice to inherit the titles of French Duc and German Prinz as the result of his family's past service to French and Austrian monarchies.

By the late nineteenth...