Today marks 134ᵗʰ Birth anniversary of Louis de Broglie, one of the most brilliant physicists of the 20ᵗʰ century. A French aristocrat who came to physics through history, he proposed in his 1924 doctoral thesis that if light could behave as particles, then particles must behave as waves. His examiners had no idea what to make of it and sent the thesis to Einstein, who replied that de Broglie had lifted a corner of the great veil.
Three years later, electron diffraction confirmed it, and in 1929 he became the only person to win a Nobel Prize for a PhD thesis. The idea underwrites every electron microscope built since.