Arthur L. Day

Arthur L. Day was a renowned American geologist and physicist who made significant contributions to the fields of seismology, geophysics, and volcanology. His work was closely associated with the United States Geological Survey (USGS) and the Carnegie Institution of Washington. Day's research focused on the earth's crust, plate tectonics, and the behavior of rocks and minerals under high pressure and temperature conditions, similar to those studied by Pierre Curie and Marie Curie. He collaborated with prominent scientists, including John Michell and Henry Cavendish, on various projects related to geodesy and gravimetry.

● Early Life and Education

Arthur L. Day was born in Brookfield, Massachusetts, and grew up in a family of modest means. He developed an interest in science and mathematics at an early age, which was encouraged by his parents and teachers at Brookfield High School. Day pursued higher education at Williams College, where he studied physics, chemistry, and geology under the guidance of professors such as Albert Michelson and Edward Morley. After graduating from Williams College, Day moved to California to work as a mining engineer and later enrolled in the University of California, Berkeley, where he earned his Ph.D. in geology under the supervision of Andrew Lawson and George Davidson.

● Career

Day's career spanned over four decades, during which he worked with various organizations, including the United States Geological Survey (USGS), the Carnegie Institution of Washington, and the National Academy of Sciences. He was appointed as the director of the Geophysical Laboratory at the Carnegie Institution of Washington, where he conducted research on the properties of rocks and minerals under high pressure and temperature conditions, similar to those studied by Pierre Duhem and Heike Kamerlingh Onnes. Day also collaborated with scientists from the University of Cambridge, such as Lord Rayleigh and J.J. Thomson, on projects related to seismology and geophysics. His work took him to various parts of the world, including Hawaii, Alaska, and Europe, where he studied volcanic eruptions and earthquakes with scientists like Frank Perret and Thomas Jaggar.

● Research and Contributions

Day's research focused on the behavior of rocks and minerals under high pressure and temperature conditions, which led to a better understanding of the earth's crust and plate tectonics. He developed new techniques for measuring the properties of rocks and minerals, including the use of high-pressure apparatus and X-ray diffraction. Day's work on the phase equilibria of minerals was influenced by the research of Josiah Willard Gibbs and Pierre Curie, and he collaborated with scientists from the University of Chicago, such as Robert Millikan and Harold Urey, on projects related to geochemistry and geophysics. His research also explored the relationship between earthquakes and volcanic eruptions, and he worked with scientists from the University of California, Los Angeles (UCLA), such as Charles Richter and Benioff, to develop new methods for predicting seismic activity.

● Awards and Honors

Day received numerous awards and honors for his contributions to geology and physics, including the Penrose Medal from the Geological Society of America and the Copley Medal from the Royal Society. He was elected as a member of the National Academy of Sciences and the American Academy of Arts and Sciences, and he served as the president of the Seismological Society of America and the Geological Society of America. Day's work was recognized internationally, and he received awards from the French Academy of Sciences and the German Academy of Sciences. He was also awarded honorary degrees from Harvard University, Yale University, and the University of Oxford, and he was elected as a foreign member of the Royal Swedish Academy of Sciences and the Accademia dei Lincei. Category:American geologists