Peter Debye was a Dutch-born US physical chemist whose investigations of dipole moments, X rays, and light scattering in gases brought him the 1936 Nobel Prize for Chemistry. Debye's studies of dielectric constants led to the explanation of their temperature dependence and of their importance in the interpretation of dipole moments as indicators of molecular structure. Aside from earning the Nobel Prize, the unit of dielectric constant is now called the debye in his honor. In crystallography, he showed that solid substances could be used in powdered form for X-ray study of their crystal structures, thus eliminating the difficult step of first preparing good crystals.