Here isotopes with longer half lives are used, which enables dating of geological formations and rocks. However, the essential ideas are analogous. In this way, some of the oldest rocks have been measured at approximately 3 billion years. He graduated in 1977 with a BSc Honours in Applied Physics from the University of Lancaster, and obtained an MSc in Medical Physics from the University of Leeds in 1987. He is interested in various theoretical aspects of radiation and radiological physics, with an interest in mathematical modelling in general.
Current research involves a theoretical description of X-ray beam spectra.