Event: Transgressing Borders of Science and Scenes of Life

Nanyang Technology University

Date: Friday, 2 March 2012

Time: 3 – 5 pm

Venue: Nanyang Executive Centre

Address: 60 Nanyang View, S(639673)

Speaker: Prof. Erling Norrby
Center for the History of Science, The Royal Swedish Academy of Sciences

Title: Transgressing borders of science and scenes of life

Abstract:
George de Hevesy was an Hungarian physicist, who received a Nobel Prize in chemistry for 1943, awarded in 1944. He is the father of the indicator method in which isotope labeling of parts of a molecule allow studies of its metabolic processing in synthesis, degradation and association with other components. The introduction of the revolutionary isotope labeling technique has been compared by Peter Medawar to the introduction of the microscope. The major application of the technique is in the life sciences and medicine and it is described with the prefix radio, like in radiobiology or radiomedicine. Hevesy was a true multidisciplinary scientist, a physicist receiving a Nobel Prize in chemistry for findings of particular relevance to biology and medicine.

His first major contribution in science was to identify the element hafnium in 1922 in Niels Bohr’s Institute in Copenhagen. This discovery was repeatedly discussed to possibly be recognized by a Nobel Prize, but this never came to be. However the discovery was important in consolidating the atomic model proposed by Bohr, which was recognized by a Nobel Prize in physics in 1922. After Hevesy’s discovery of hafnium only a few elements remained to identify to complete the periodic table containing 92 naturally occurring elements.

Hevesy had his early training in Ernest Rutherford’s laboratory. Rutherford proposed that he should separate the lead isotope Radon D from non-radioactive lead. This turned out to be impossible. Hevesy then turned the problem around and proposed that the radioactive compound could be used to trace its mother substance lead. He referred to this as the indicator method. It took considerable time before this method could find a broad application. In the early phase the only isotopes that were available were toxic and short lived and emitted destructive energy particles. The situation changed in the 1930s when Harold Urey discovered the heavy hydrogen isotope deuterium and soon thereafter Frederick and Irène Joliot-Curie demonstrated that bombardment of aluminum by alpha particles led to the formation of radioactive material. Both these advances were recognized by Nobel prizes in chemistry in 1934 and 1935. Very soon a range of isotopes became available – 32-P, 14-C etc. Blood volume and the turnover of fluids could be readily determined by dilution techniques and the turnover of solid substances like bone and of different kinds of intact cells, dispersed in blood, representing tissues in intestines etcetera could also be determined. New methods for diagnostics and treatments in medicine using radioisotopes were developed.

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