The Ernest beginnings of particle physics
The history of physics is filled with world-changing experiments. The latest, at CERN in Switzerland, hopes to offer the world another great leap forward in understanding and another step in a process which began in Manchester.
CERN’s Large Hadron Collider, where scientists will attempt to recreate the very beginnings of the Universe, may seem a long way from an early twentieth century Manchester laboratory, but the link between the two is undeniable - and that link is the pioneering scientist, Ernest Lord Rutherford.
Rutherford was a New Zealander, who came to Manchester in 1907 to take up the Chair of Physics. He was already a notable scientist, having investigated the disintegration of elements and the chemistry of radioactive substances while at Montreal’s McGill University in Canada.
That work would win him the Nobel Prize for Chemistry the year after he arrived in Manchester, but by that time, he was already surging on to greater discoveries, aided by one of the finest team of scientists ever assembled.
The University of Manchester in 1912
Amongst the students Ernest oversaw at the University were Hans Geiger, who would go on to invent the radiation counter; Lawrence Bragg, who won the 1915 Nobel Prize for his work on x-ray crystallography and would be Rutherford’s successor in Manchester; Ludwig Wittgenstein, the analytic philosopher; and the great Niels Bohr, seen by many as the most gifted scientist of the twentieth century.
Little wonder then that the city became a global centre for scientific research, all focussed around Rutherford, a man of such brilliance and repute that Albert Einstein would later call him "a second Newton".
Discovering the nucleus
It was one particular path of investigation though that would bring Ernest his fame and the chance to change the world forever – his studies of the atom.
Shortly after arrival, he invented the Rutherford-Geiger detector (along with Hans Geiger), which allowed him to detect individual nuclear particles by electrical means. For Ernest, it was not enough; he wanted to know what was inside a single atom.
Through a series of experiments, he determined that the majority of the mass of an atom was concentrated in its nucleus – a particle 1000 times smaller than the atom itself – with the rest being made of a cloud of orbiting electrons.
The Rutherford atomic model
It was a discovery that changed the face of science. Prior to it, the atom had been presumed to be the smallest particle in the universe – now, Rutherford was on the verge of 'splitting the atom' and discovering what was inside.
In 1911, he presented his model of the newly discovered atomic structure and set about planning the experiments that would prove the idea it presented to Ernest – that just like the atom, the nucleus had smaller components.
Interrupted by war
His path of discovery was brought to an abrupt halt by the First World War. Having been knighted for his work in 1914, Ernest had set out for Australia and New Zealand for a scientific meeting with conflict on the horizon.
By the time his boat docked, war had been declared and he found his talents being used for the research of submarine technology and underwater acoustics, rather than physics.
The war would not only delay his atomic work, it would also cost him the life of one of his most brilliant students. Henry Mosely was on track to receive the Nobel Prize for his work with X-rays, but, sadly, was killed in action at Gallipoli.
Ernest Lord Rutherford
The incident had a profound effect on Rutherford; when America joined the conflict in 1917, he unsuccessfully pleaded the case for allowing young American scientists to serve their country in laboratories, rather than trenches.
It wasn’t his only effort towards saving lives. In 1916, aware of the power his own investigations could unleash, he publicly stated that he hoped mankind wouldn’t work out how to extract the energy from the nucleus until "man was living at peace with his neighbour".
A world-changing reaction
Towards the end of the war, Ernest was allowed to return to his studies, which were reaching a critical stage. In 1917, he undertook a long series of experiments in which he discovered that the nuclei of certain light elements, such as nitrogen, could be 'disintegrated' by the impact of particles coming from a radioactive source, and that during this process fast protons were emitted.
It was the first artificially induced nuclear reaction and it would change the world forever. Along with the eventual founding of CERN in 1954, it would lead to nuclear power and the atomic bombs that devastated Hiroshima and Nagasaki in World War Two.
A year after his breakthrough, Ernest left Manchester to take up a position at Cambridge University. He continued to make great strides in physics and help his students push forward in the field, being given a life peerage for his work in 1931, but he never again matched his achievements in Manchester.
In essence, Lord Rutherford had created a new discipline in the city, that of nuclear physics – a field that would evolve into particle physics, the main discipline of the scientists at CERN and the one which is driving the experiment there.
last updated: 10/09/2008 at 11:02