Louis de Broglie began as a history student before turning toward mathematics and physics, ultimately reshaping modern science. In his 1924 PhD thesis, he proposed that particles such as electrons possess wave-like properties, challenging established ideas about matter. Experiments later confirmed his hypothesis, helping establish a foundation for quantum mechanics. De Broglie received the 1929 Nobel Prize in Physics, and his work influenced Schrödinger’s wave mechanics and technologies such as electron microscopes.