Physicists are like the people who draw atlases. Imagine a bigger atlas with a lot of information, full of places and objects that are not as familiar as things in everyday life. My work added some more information and more insight into the geography of the physical world. I pioneered the use of neutron scattering to find out about what atoms do, for which I shared the 1994 Nobel Prize in Physics.
When neutrons pass through material, some are deflected by atoms and their level of energy changes. The triple-axis spectrometer that I invented measures the energy of neutrons after they have been scattered by the atoms of a crystal. As a neutron collides with an atom in a crystal, it sets off vibrations. Because each crystal has a unique atomic structure, it also has a characteristic vibration pattern. I studied the frequency of these vibrations in order to calculate the forces between atoms.
I measured this vibrational energy by comparing the speed of neutrons entering and leaving a sample. I passed a monochromatic beam of neutrons through the sample and the neutrons emerged travelling at different speeds. To identify their speeds, I passed them through another crystal, which diffracted them in different directions according to their velocity.
Today thousands of researchers use neutron scattering in materials physics, chemistry, biology and engineering. While my research was basic and has no direct applications to ordinary life, it did make many practical things possible, including infra-red detectors and exhaust-cleaning systems for automobiles.
Much of the theory of diffraction and lattice vibrations was there when I started my research. I just realised that it could be done with the current technology. I was in the right place at the right time. We were intellectual explorers - we were like the first explorers to cross the Atlantic, finding out that it was not a narrow sea but a wide ocean
