Unstable nuclei reveal the need for a complete theory of the nucleus

Human knowledge is often biased by limited information, and science is not free from this problem. Nuclear-physics studies have essentially been restricted to stable nuclei that contain almost equal numbers of protons and neutrons. However, we have only recently begun to probe the structure of unstable nuclei, which are very rich in either protons or neutrons, using beams of radioactive nuclei. These studies have revealed a bias in our knowledge of nuclear physics. Now scientists are working hard to formulate a new model that can explain the structure of both stable and unstable nuclei, based on a rigorous many-body theory. In this article the author explains our current knowledge of nuclear physics. (UK)