Crystallography

Physician turned chemist who made platinum malleable, discovered palladium and rhodium, first saw the dark lines of the solar spectrum, and invented the camera lucida and reflecting goniometer.

chemistry, metallurgy, optics

French physicist who discovered piezoelectricity with his brother Jacques, formulated the symmetry principle and Curie's law of magnetism, and co-discovered polonium and radium with Marie Curie.

physics, crystallography, piezoelectricity

Discoverer of the diffraction of X-rays by crystals, author of the first relativity textbook, and a public defender of Einstein's physics in Nazi Germany.

x-ray diffraction, crystallography, special relativity