4. THE PROSPECTS OF PURE SCIENCE

by Sir John Cockroft

(Extracts from the Presidential Address to the British Association for the Advancement of Science, 1962)

If we look forward to the prospects for pure science, we see that it is an intensely creative phase. Rutherford's burning desire to learn the innermost secrets of the atom is shared by the generation of his grandchildren. The primitive nuclear particle accelerators of Rutherford's later years which produced hydrogen nuclei with energies of a few hundred thousand volts have been succeeded by enormous nuclear accelerators producing particles of 100,000 times greater energy at 10,000 times the cost.

An understanding of these particles, connected as they are with the basic forces of the Universe, presents a tremendous challenge to the human intellect. If we succeed, our understanding of the physical Universe will be greatly enriched, as it has been enriched in the past by Newton's theory of gravitation, Bohr's' theory of the nuclear atom, and by wave and quantum mechanics. The study of elementary particles is likely to continue to be in the forefront of physics for several decades and will continue to attract many of the world's best scientists.

Whilst this work with very high-energy particles goes on, another group of nuclear physicists working with less energetic particles of very precisely defined energies are exploring the detailed structure of the nucleus and its vibrations and oscillations and are also exploring the nuclear processes which lead to the evolution of the elements in the stars. So we now know how this evolution starts - by fusing together hydrogen nuclei in a sequence of processes to form helium - and how, much later in the life of a star, as it gets hotter, helium nuclei fuse together to form heavier elements. This can go on with ever-increasing temperatures until the terrific nuclear explosion of the supernovae occurs. In these explosions, the very heavy elements are born.

Solid state physics attracts as many research workers as nuclear physics, and their achievements, though less glamorous and less publicized, have been great and perhaps of more immediate practical use. They have been helped, like the nuclear physicists, by the feed-back from technology producing ever more powerful and discriminating instruments.

Electron microscopes of high resolution reveal imperfections in crystal planes of metals and especially those known as dislocations. The ease with which dislocations move through metals determines their ductility and we now understand why metals change their properties with increasing age, why they become more brittle at lower temperatures and how impurities affect them.

Another branch of solid state physics, the study of semiconductors, is now in a rapidly developing stage. Starting as an academic subject in the 1930s, it has led to the development of transistors, to rectifiers of increasing importance in power generation, to detectors of infra-red radiation of great virtuosity, to devices for producing refrigeration, to solar batteries and many other products.

The Earth and environmental sciences are in an equally lively state. Oceanographers believe that more extensive studies of the nutrient content of the deep ocean and methods of increasing the turnover could lead to greatly increased fish protein production, which at present only provides about one per cent of the Earth's food. Studies of the ocean floor show vast reserves of minerals, especially nickel, cobalt and copper.

Recent discoveries in the life sciences have been no less notable and have been greatly helped by the developments in techniques such as high precision X-ray crystallography, the electron microscope, chromatography and radioisotopes. Among the most important developments of the last decade has been the discovery of the general chemical structure of the giant molecules, known for short as DNA, which determine our hereditary characteristics.

Another great biological development started with the work of Hevesy in 1922 when he used radioactive lead as a tracer to study biological processes. The use of nuclear reactors to produce tritium, radiocarbon and a multitude of other tracers has greatly extended the range of these tools and enables the biochemist to unravel the very complex processes of living organisms, to show that the whole of the components of our bodies are in a general state of flux and to show how the break-down of a single step in the complicated chemical chain can lead to disease.

One of the most important problems of the next half century is the control of human fertility and the provision of an increasing supply of human foodstuffs to outstrip the doubling of world population, which seems to be regarded as inevitable in this period. The biochemists seem now to be making progress in fertility control, and the application of well-known technology to increase agricultural production in under-developed countries may be supplemented by turning fishing from a hunting to a farming operation and by new approaches to providing protein for human food.

(from New Scientist, 30th August, 1962)