A history of imaging

In 1895 German physicist Wilhelm Röntgen was in his laboratory at the University of Munich researching cathode rays – the phenomena where an electrical current passing through an evacuated glass tube causes the end of the tube to glow (or fluoresce) - when he noticed that a screen painted with barium platinocyanide over a metre away on his lab bench was shimmering. Intrigued, he placed a number of objects between the vacuum tube and the screen and still the screen glimmered. Röntgen had discovered X-rays, for which he went on to win the inaugural Nobel Prize for Physics in 1901.

Röntgen's discovery attracted the attention of medical researchers, given the ability of the new "rays" to penetrate beneath the skin, but also physicists who were more interested in trying to establish the nature of the mysterious rays. In 1912 Max von Laue produced the first diffraction pattern and William Lawrence Bragg reformulated von Laue’s conditions for diffraction into what became known as Bragg’s Law, which gives a direct relationship between the crystal structure and its diffraction pattern. X-ray Crystallography was born.

Not long afterwards in Manchester, Ernest Rutherford, alongside his work to split the atom realised that accelerated particles provided a useful tool for investigating the structure of matter. Physicists around the world began looking into ways to accelerate particles and it was through this work that an alternative source of X-rays grew. The first accelerators (cyclotrons) were built by particle physicists in the 1930s. In these machines, the nucleus of the atom was split using the collision of high-energy particles. From the results of these collisions the physicists tried to deduce the laws of fundamental physics that govern our world and the whole of the universe.