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Friday, September 13

The Crocodile of the Cavendish Labs: Rutherford, the second Newton

John Katsaras, ORNL Neutron Sciences Directorate ,
Materials Science and Technology, Materials Theory Group
11:00 AM — 12:00 PM, Joint Institute for Computational Sciences, Building 5100, Auditorium/Room 128
Contact: Ann Strange (strangear@ornl.gov), 865.576.7054

Abstract

Albert Einstein called him the second Newton, and he is regarded by many as one of the greatest physicists of all time – even though he was awarded the Nobel Prize in Chemistry1,2. Many of us know of Rutherford's "gold foil" experiment (performed by Hans Geiger and Ernest Marsden in 1909) proving the existence of atomic nuclei and a model of the atom (1911) that is accepted to this day. The so-called Geiger-Marsden experiment led to the demise of J.J. Thompson's (Rutherford's mentor) "plum pudding" model of the atom, in which the positive and negative charges were evenly distributed. Notwithstanding his Nobel Prize, if this was Rutherford's singular contribution to science, his name would be forever enshrined in the annals of physics. However, while director of the Cavendish Laboratories he was a force behind Chadwick's 1932 discovery of the neutron3 (Rutherford proposed its existence in 1921), and in the same year, the first controlled nuclear disintegration experiments by Cockroft and Walton4. Today's seminar will give a brief account of the different events that led to the two discoveries of the Annus mirabilis of 1932.

Notes:

11908 Nobel Prize in Chemistry – "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances"

2"I have dealt with many different transformations with various periods of time, but the quickest that I have met was my own transformation in one moment from a physicist to a chemist." Ernest Rutherford (Nobel banquet 1908).

31935 Nobel Prize in Physics – "for the discovery of the neutron"

41951 Nobel Prize in Physics – "for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles"