Harold Urey
Early Life and Education
Harold Clayton Urey was born on April 29, 1893, in Walkerton, Indiana, United States. He was the son of Samuel Clayton Urey, a school teacher and minister, and Cora Rebecca Reinoehl. Urey's upbringing in a rural environment instilled in him a deep appreciation for nature and the sciences. He attended the University of Montana, where he earned a Bachelor of Science degree in Zoology in 1917. His initial interest in biology shifted towards chemistry, leading him to pursue graduate studies at the University of California, Berkeley. Under the guidance of Gilbert N. Lewis, Urey completed his Ph.D. in Chemistry in 1923, focusing on the thermodynamic properties of gases.
Academic Career and Research
After obtaining his doctorate, Urey spent a year as a National Research Council Fellow at Harvard University, where he worked with the eminent chemist Theodore William Richards. In 1924, he joined the faculty at Johns Hopkins University as an associate in chemistry. Urey's early research focused on the properties of molecules and the application of quantum mechanics to chemical problems. His work on the hydrogen isotope led to the discovery of deuterium, a stable isotope of hydrogen, in 1931. This discovery was pivotal in advancing the field of isotopic chemistry and earned Urey the Nobel Prize in Chemistry in 1934.
Discovery of Deuterium
Urey's discovery of deuterium was a groundbreaking achievement in the field of chemistry. By employing a method of fractional distillation of liquid hydrogen, Urey and his collaborators were able to isolate deuterium, which has a nucleus containing one proton and one neutron, as opposed to the single proton found in the nucleus of ordinary hydrogen. This discovery not only provided a new tool for chemical analysis but also had significant implications for nuclear physics and the development of nuclear energy.
Contributions to Nuclear Chemistry
During World War II, Urey played a crucial role in the Manhattan Project, the United States' effort to develop the atomic bomb. He was involved in the development of the gaseous diffusion method for the separation of uranium isotopes, which was essential for producing the fissile material used in nuclear weapons. Urey's expertise in isotopic separation and his leadership in the project were instrumental in the successful creation of the atomic bomb.
Post-War Research
After the war, Urey continued his research in nuclear chemistry and became a prominent advocate for the peaceful use of nuclear energy. He joined the University of Chicago, where he contributed to the development of the field of cosmochemistry, the study of the chemical composition of the universe. Urey's work in this area included the analysis of meteorites and the study of the origin of the solar system.
Cosmochemistry and the Origin of the Solar System
Urey's interest in cosmochemistry led him to propose theories about the formation of the solar system. He hypothesized that the planets formed from a primordial solar nebula, a rotating disk of gas and dust surrounding the young Sun. Urey's work laid the foundation for the modern understanding of planetary formation and influenced subsequent research in the field.
Analysis of Meteorites
Urey's analysis of meteorites provided valuable insights into the early history of the solar system. By studying the isotopic composition of meteorites, he was able to deduce information about the conditions and processes that occurred during the formation of the planets. His research contributed to the development of the isotopic dating method, which allows scientists to determine the age of rocks and other geological materials.
Later Years and Legacy
In his later years, Urey continued to be an influential figure in the scientific community. He was a vocal advocate for the peaceful use of nuclear energy and a proponent of international cooperation in scientific research. Urey's contributions to chemistry, nuclear physics, and cosmochemistry have left a lasting impact on the scientific world. He passed away on January 5, 1981, in La Jolla, California.