- New Zealand-born British physicist who was a pioneer of subatomic physics. He discovered the atomic nucleus and named the proton. Rutherford demonstrated that radioactive elements give off three types of rays, which he named alpha, beta, and gamma, and invented the term half-life to measure the rate of radioactive decay. For this work he was awarded the Nobel Prize for chemistry in 1908.
Biography: Current theories of nuclear fission and fusion reactions are well accepted; these reactions now drive nuclear power plants and atomic bombs. But when the notion that some atoms could spontaneously disintegrate into other atoms was first advanced in 1902 by Ernest Rutherford, it found resistance among his colleagues, who believed that the chemical elements of which known matter was composed were indestructible and immutable. Undaunted, this New Zealand-born physicist then made a large number of discoveries in rapid succession, including the discovery of three kinds of radioactivity (alpha, beta, and gamma rays), and his brilliance and prodigious output soon won over his critics. By the time he garnered the Nobel Prize for chemistry six years later, he had written 80 more scientific papers. His explanation in 1903 of the radioactive decay of uranium-that pieces of uranium atoms were literally breaking off and being emitted, thereby transforming the uranium into a new element-was compelling and soon well accepted. Astonishingly, what are arguably his greatest discoveries came three years after he won the Prize. In 1911, he showed that atoms were composed of smaller constituents: electrons orbiting around a positively charged nucleus. While the rudiments of this idea had already been proposed by others, Rutherford's experimental research conclusively demonstrated its correctness. Rutherford later identified the proton, one of the particles found in the nucleus. The Rutherford atom, as it came to be known, is the model of atomic structure from which today's well-established quantum mechanical theories of atomic structure derive. Rutherford also succeeded in inducing the first artificial fusion, fusing deuterium atoms together into radioactive tritium and a light isotope of helium.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.