The Discovery of the Nucleus

By ‘unobservable’ Godfrey-Smith means ‘not directly accessible to our senses.’ In such cases, philosophers of science distinguish the observable from the detectable. In science we work with models, conceptual representations of real things and processes.[2] When the object of study is not directly accessible to our senses, we also have to make a distinction between what is observable and what is detectable. An object or process is detectable, Godfrey-Smith continues, “if either it is observable or its presence can be very reliably inferred from what is observable.”[3] In this sense, nuclei are detectable. If you are not convinced, then medical radiology, nuclear power stations, and nuclear weapons make the point that something at the heart of matter exists that we call the nucleus, whose realities have been at least partially captured by our models. This article is a short account of how models of the atom and its nucleus were developed.