Unpredictability and chance in scientific progress

It is much easier to interpret the past than to predict the future, and especially so when dealing with the vicissitudes of science. The laser, for example, which did not emerge until 1960, could have been assembled decades earlier by perspicacious physicists following Einstein’s classic paper in 1917 on population inversion in electronic energy levels. Equally, a widely read, mathematically-oriented engineer or computer scientist, knowing Radon’s work in Leipzig, also in 1917, could have foreseen and accelerated the arrival of the technique of tomography, with all that it has done to revolutionize medicine. In this article, I cite examples of devices, techniques, procedures, and theories that exhibit a variety of different origins and subsequent development. In some instances progress had been extraordinary rapid, in others extremely slow; and in several the element of chance and coincidence has played a vital role. With the exception of the computer itself few electronic devices have had a more profound impact on the progress of experimental science and on social interaction among human beings than the charge coupled device, otherwise known as the CCD. It has fundamentally transformed the whole of observational astronomy and very large sections of terrestrial and marine biology. The study and application of nanoscience no less than progress in nanotechnology have likewise been revolutionized by the CCD, which is an ultrasensitive detector that picks up extremely low levels of light ranging from the infra red to the visible, the ultra violet and even X-rays. It is more than a thousand times more sensitive than the most sensitive photographic plate, which is why it is nowadays the basis of modern digital and video cameras, optical scanners and camcorders, as well as spectrometers, fax machines and other high performance imaging facilities that are these days a part of mobile phones. (One million chil-