1934 – England
X-ray crystallography. X-rays are unique in that their wavelength is about the length of bonds within molecules. When X-rays hit a crystallized molecule, the electrons surrounding each atom cause the beam to bend. Because there are many atoms the result is that when the X-rays exit the crystal and fall onto a photographic plate, they produce a series of light and dark patches. Measuring the intensity and relative position of each patch indicates the relative positions of atoms within the crystal.
With her co-worker John Desmond Bernal (1901-1971) Hodgkin produced the first diffraction patterns for proteins.