James Rainwater starts graduate study in physics as a teaching assistant at Columbia University. During his first two years, he takes courses under I.I. Rabi, Enrico Fermi, Edward Teller and J.R. Dunning.

James Rainwater is again appointed Director of the Nevis Cyclotron Laboratory at Columbia.

At the outbreak of World War II James Rainwater works with W.W. Havens, Jr. and C.S. Wu under Dr. Dunning for the Manhattan Project mainly doing pulsed neutron spectroscopy using the small Columbia cyclotron.

James Rainwater becomes Director of the Nevis Cyclotron Laboratory at Columbia University.

James Rainwater becomes Pupin Professor of Physics at Columbia University, position that he holds almost until his death.

After the death of his father, James Rainwater relocates with his mother and his grandmother to Hanford, California. Here his mother re-marries to George Fowler a few years later. Rainwater in his schooling through high school excels in physics, mathematics and chemistry.

James Rainwater dies in Yonkers of heart failure at age 68.

James Rainwater first becomes Instructor, reaching the rank of Full Professor in 1952. At the end of the 1940s Rainwater begins developing his theory that not all atomic nuclei are spherical. His ideas are later tested and confirmed by Bohr's and Mottelson's experiments. Rainwater also contributes to the scientific understanding of X-rays and participates in the United States Atomic Energy Commission and naval research projects.

James Rainwater receives one third of the Nobel Prize in Physics along with Aage N. Bohr and Ben R. Mottelson "for the discovery of the connection between collective motion and particle motion in atomic nuclei and the development of the theory of the structure of the atomic nucleus based on this connection".

James Rainwater enters the California Institute of Technology as a chemistry major before switching to physics and graduating in this subject with a B.S.

Rainwater experimentally finds that the electric quadrupole moment of some nuclei is bigger than expected according on models with spherical symmetry. He puts forward a theoretical interpretation of this phenomenon in April 1950: he suggests that the nucleus is divided in an inner and an outer part, and postulates the existence of unequal centrifugal forces in the outer part, which cause the permanent deformation.

James Rainwater is born in Council, Idaho, to Leo Jaspar Rainwater, a civil engineer, who dies in the great influenza epidemic of 1918, and Edna Eliza Teague.