ABSTRACT
In 1903 the physicist Albert Michelson made an astonishing pronouncement. Confident of the advances made by the great physicists of the Victorian era, such as Lord Kelvin, James Clark Maxwell and Thomas Edison, he declared that ‘the most important fundamental laws and facts of physical science have all been discovered, and these are now so firmly established that the possibility of their ever being supplemented in consequence of new discoveries is exceedingly remote’.1 In so doing he followed what appeared to be a long-established tradition that eminent physicists should make bold and far-reaching statements on the nature of the universe and its physical laws.2 Unfortunately, Michelson’s timing could not be worse as early twentieth-century physicists were about to make a string of discoveries that would fundamentally alter our perceptions of the universe. The world as Michelson understood it was about to be turned on its head by the work of three men: Max Planck, Albert Einstein and Ernest Rutherford. The first, Planck, was a respected German physicist who had done work on entropy, but had done little to distinguish himself. Then in 1900 he developed his ‘quantum theory’ which posited that energy did not flow as a stream or wave as had been imagined before, but rather was carried by packets or quanta. This seemingly simple, yet deceptively complex, thesis was to have a profound effect upon our understanding of the physical universe. Planck’s
thesis proved to be the foundation for the modern discipline of quantum physics, a discipline that first came to the attention of the wider public when in 1905 a young Swiss patents clerk called Albert Einstein wrote five papers for the Annalen der Physik. Three of these papers are widely accepted to be among the best in the history of physics and examined photoelectric effects by applying Planck’s new quantum theory, Brownian Motion and a ‘Special Theory of Relativity’. As Bill Bryson notes in his Short History of Nearly Everything, ‘the first won its author a Nobel Prize and explained the nature of light (and also helped make television possible among other things). The Second provided proof that atoms do indeed exist – a fact that had surprisingly, been in some dispute. The third merely changed the world’.3
Thus within two years of Michelson’s pronouncement much of our understanding of the physical universe had been turned on its head by this new development; but for Michelson worse was to follow. In 1895, a young South African named Ernest Rutherford had won a scholarship to the world famous Cavendish Laboratory at the University of Cambridge. By 1911, Rutherford had become obsessed with the nature of atoms, the basic building blocks that form the constituent parts of the universe. That year he proposed his ‘theory of atomic nuclei’, which suggested that all the positive charge and most of the mass of an atom must be contained in a tiny nucleus at the atom’s centre, with the negatively charged electrons ‘in orbit’ about this nucleus. To prove his thesis Rutherford had to ‘split’ the atom to prove that he could release matter from this nucleus, something which he finally succeeded in doing in 1919 when he showed that by firing alpha-particles into nitrogen gas a small amount of hydrogen could be produced. In so doing he also established that energy could be released from the nucleus of an atom, thereby proving an essential part of Albert Einstein’s Special Theory of Relativity: the unification of energy and mass, usually represented by the famous equation E=mc2.4 With Rutherford providing the link between quantum theory and nuclear physics the Newtonian view of the universe, which was at the heart of Michelson’s beliefs, had been rewritten in less that 20 years.
