Rutherford and the Birth of Nuclear Physics

Dr. David Jenkins, a lecturer in the Department of Physics at the University of York with a focus on experimental nuclear physics, is introduced as the speaker. He discusses his role in organizing events for the Institute of Physics and his public lecture program. The speaker expresses excitement to share insights on the birth of nuclear physics and Ernest Rutherford's significant contributions, especially leading up to the centenary of Rutherford's discovery of the atomic nucleus in 1911. Dr. Jenkins plans to discuss Rutherford's early experiments, his legacy in science, and the current state of nuclear physics.

The paragraph delves into Ernest Rutherford's early life and career, highlighting his move from New Zealand to Cambridge University, funded by a scholarship from the Great Exhibition of 1851. Rutherford's initial interest in radio and his subsequent work in radioactivity under the influence of JJ Thompson at Cambridge are covered. The narrative then shifts to Rutherford's professorship at McGill University in Montreal, where he collaborated with chemist Frederick Soddy. Together, they conducted groundbreaking experiments on radioactive materials, leading to the publication of numerous scientific papers and Rutherford's concept of half-life.

This section discusses Rutherford's awarding of the Nobel Prize in Chemistry in 1908 for his work on the disintegration of elements and the chemistry of radioactive substances. It also covers his discovery of the half-life concept and his estimation of the Earth's age based on radioactivity, which was a significant contribution to geology. The paragraph mentions Rutherford's correspondence with the Curies and his use of early experimental apparatus, some of which is preserved at McGill University.

The paragraph describes Rutherford's move to Manchester University and his famous gold foil experiment with Hans Geiger and Ernest Marsden. This experiment, involving the scattering of alpha particles, led to the discovery that atoms have a dense nucleus, contradicting the prevailing 'plum pudding' model. Rutherford's model proposed a central nucleus with electrons orbiting around it, marking a significant shift in the understanding of atomic structure.

Rutherford's exploration into nuclear reactions and transmutation is detailed, including his experiments firing alpha particles at nitrogen, which led to the discovery of the proton. The paragraph also discusses Rutherford's prediction of the neutron in 1921, which was later confirmed by James Chadwick. These findings expanded the understanding of the atomic nucleus, leading to the modern atomic model consisting of protons and neutrons.

The paragraph focuses on the current state of nuclear physics, the potential of nuclear fusion for energy production, and the role of nuclear physics in understanding stellar processes and supernovae. It also touches on the vast number of isotopes that can theoretically exist and the importance of Rutherford's mentorship, which influenced a generation of scientists, many of whom went on to receive Nobel Prizes.

This section reflects on Rutherford's frugality and his approach to scientific funding, contrasting it with the substantial investments in modern scientific facilities like the LHC at CERN. It discusses the evolution of scientific collaboration from correspondence to multinational teams and the challenges of operating in a 'big science' environment. The speaker ponders how Rutherford would have adapted to these changes and the scale of modern scientific apparatus.

The final paragraph concludes the presentation by celebrating Rutherford's pioneering role in nuclear physics and his influence on subsequent generations of scientists. It highlights Rutherford's tenacity and the primitive yet effective methods he used to uncover the structure of matter, setting the stage for the field of nuclear physics as we know it today.