Development Of Atomic Energy: Rotary Address

Bay of Plenty Beacon, Volume 11, Issue 91, 21 October 1947, Page 4

Development Of Atomic Energy: Rotary Address

Whakatane Rotarians last Wednesday listened to an intensely interesting though, to the layman, highly technical, address on atomic energy and its development. The speaker, Mr W. Dreghorn, though limited as to time, gave a thoroughly lucid survey of the subject which will help his hearers to a much clearer understanding of a force which seems destined to play a trenendous part in the world’s future. Introducing the subject with the decision of the American and British Governments to put atomic bopbs into production with full scale plants in America (on account of bombing raids in Britain), and with the full co-operation of the Canadian Government, Mr Dreghorn followed on with ,an historical survey of the scientific investigations that led to the realisation of atomic force.

Though well-informed as to the background developments, and no doubt able to conjecture future advances with decisive potentialities so far as modern warfare was conerned, the Germans were far behind our own and the American scientists in 1942 and 1943. Mr Dreghorn explained that all matter is made of 92 elements, and from the atoms of one or mere of these all the chemical compounds that exist in nature are formed. At first, he said, scientists believed that atoms of one kind could be changed into those of another, but went on to trace developments in the investigations into radio activity and the modifications of the elements from the time of the isolation of radium by Madame v t Curie up to Rutherford’s first steps towards the ■ artificial disintegration of the atom in 1919.

It was found, Mr Dreghorn explained, that alpha particles from radium C. would in rare instances collide with a nucleus of nitrogen atom in such a way that it broke up and formed two other atomic species, nitrogen and oxygen. Though these reactions released enormous energy, they were not self-propagat-_ ing, quite different from the normal chemical processes of combustion of oil and coal. It was clear, therefore, that to tap the hidden reserves of energy in atomic nuclei, scientists must find a reaction that would propagate itself. From Chadwick’s discovery of the neutron in 1932, Mr Dreghorn then traced international efforts to the point where it was hoped that uranium would yield the chain re-aetion necessary to produce atomic energy in a form that could be harnessed to man’s purposes. It was found that a slowing-down medium was necessary, and the most suitable was discovered to be . heavy hydrogen, or its compound, “heavy water”, of which practically the whole world stock then existing was 165 litres brought to England by two French physicists in 1940. Imperial Chemical Industries undertook the manufacture of uranium, and the Cambridge group of scientists who had been co-operating in Sir James Chadwick’s experiments went to Montreal, where the production of “neavy water” began. The world knows the sequel—the atomic bomb. Mr Dreghorn completed an absorbing address with some general notes on nuclear physics and the possible future developments in atomic experiments. s