Ramsey got a chance to work on military objects that helped changed history such as the Manhattan Project. Before doing that he was a radar consultant to the Secretary of War. When he was a radar consultant he help eveloped the first three centimeter wavelength magnetrons and the related radar systems. Ramsey focussed his scientific research on the properties of atoms nuclei, molecules,and elementary particles. They include the nature of nuclear forces, the structural shape of nuclear particles, key contributions to the knowledge of magnetic moments, the thermodynamics of energized populations of atoms, molecules and spectroscopy. Ramsey became a professor at Columbia University until 1947. He then joined the faculty at Harvard and became Higgins Professor of Physics in 1966. He officially retired from Hrvard in 1986. Even though he is retired he still goes to his office at Harvard and continues to write and publish. When he was at harvard he established a molecular beam laboratory. This is where he had the intent of doing accurate molecular beam magnetic resonance experiments. They failed at doin this many times because of not having a strong enough magnetic field. Then he invented the separated oscillatory field method. That method permitted them to achieve more accuracy with the magnets available. They used this method to measure the molecular and nuclear properties including nuclear spins, nuclear magnetic dipole and electric quadrupole moments, rotational magnetic moments of molecules, spin-rotational interactions, spin-spin interactions, electron distributions in molecules, and so on. During this period is when he helped develop the atomic clocks.Daniel Kleppner and Ramsey invented the atomic hydrogen maser. He was awarded the Nobel Prize in physics for the " invention of the separated oscillatory fields method and its use in the hydrogen maser and other atomic clocks." Experimental Nuclear Physics, Nuclear Moments, , Molecular Beams, and Quick Calculus, were some of the books he wrote. Ramsey published many writtings and was honored with many awards.