02 May, 2019

Edward Hulburt

Edward Olson Hulburt was an American geophysicist . He is considered the discoverer of the electrical properties of the ionosphere and the interaction between the sun and the earth's atmosphere. Besides, he was the first to realize that the blue color of the sky during the blue hour has a different cause than that during the day.

In 1931 he developed a study on the greenhouse effect in the Earth's atmosphere.

Felix Bloch

Felix Bloch was a Swiss-American physicist and Nobel physics laureate who worked mainly in the U.S. He and Edward Mills Purcell were awarded the 1952 Nobel Prize for Physics for "their development of new ways and methods for nuclear magnetic precision measurements." In 1954–1955, he served for one year as the first Director-General of CERN. Felix Bloch made fundamental theoretical contributions to the understanding of electron behavior in crystal lattices, ferromagnetism, and nuclear magnetic resonance.

Bloch was born in Zürich, Switzerland to Jewish parents Gustav and Agnes Bloch. He was educated at the Cantonal Gymnasium in Zürich and at the Eidgenössische Technische Hochschule (ETHZ), also in Zürich. Initially studying engineering he soon changed to physics. During this time he attended lectures and seminars given by Peter Debye and Hermann Weyl at ETH Zürich and Erwin Schrödinger at the neighboring University of Zürich. A fellow student in these seminars was John von Neumann. Bloch graduated in 1927, and was encouraged by Debye to go to Leipzig to study with Werner Heisenberg. Bloch became Heisenberg's first graduate student, and gained his doctorate in 1928. His doctoral thesis established the quantum theory of solids, using Bloch waves to describe electrons in periodic lattices.

He remained in European academia, working on superconductivity with Wolfgang Pauli in Zürich; with Hans Kramers and Adriaan Fokker in Holland; with Heisenberg on ferromagnetism, where he developed a description of boundaries between magnetic domains, now known as "Bloch walls"; with Niels Bohr in Copenhagen, where he worked on a theoretical description of the stopping of charged particles traveling through matter; and with Enrico Fermi in Rome. In 1932, Bloch returned to Leipzig to assume a position as "Privatdozent" (lecturer). In 1933, immediately after Hitler came to power, he left Germany because he was Jewish, returning to Zürich, before traveling to Paris to lecture at the Institut Henri Poincaré.

In 1934, the chairman of Stanford Physics invited Bloch to join the faculty. Bloch accepted the offer and emigrated to the United States. In the fall of 1938, Bloch began working with the 37 inch cyclotron at the University of California at Berkeley to determine the magnetic moment of the neutron. Bloch went on to become the first professor for theoretical physics at Stanford. In 1939, he became a naturalized citizen of the United States.

During WWII, Bloch briefly worked on the atomic bomb project at Los Alamos. Disliking the military atmosphere of the laboratory and uninterested in the theoretical work there, Bloch left to join the radar project at Harvard University.

After the war, he concentrated on investigations into nuclear induction and nuclear magnetic resonance, which are the underlying principles of MRI. In 1946 he proposed the Bloch equations which determine the time evolution of nuclear magnetization. Along with Edward Purcell, Bloch was awarded the 1952 Nobel Prize in Physics for his work on nuclear magnetic induction.

When CERN was being set up in the early 1950s, its founders were searching for someone of the stature and international prestige to head the fledgling international laboratory, and in 1954 Professor Bloch became CERN's first Director-General, at the time when construction was getting under way on the present Meyrin site and plans for the first machines were being drawn up. After leaving CERN, he returned to Stanford University, where he in 1961 was made Max Stein Professor of Physics.

At Stanford, he was the advisor of Carson D. Jeffries, who became a professor of Physics at the University of California, Berkeley.

In 1964, he was elected a foreign member of the Royal Netherlands Academy of Arts and Sciences.

Bloch died in Zürich in 1983.

Elmer Imes

Elmer Samuel Imes was the second African American to earn a Ph.D. in Physics and the first in the 20th century. He was among the first African-American scientists to make important contributions to modern physics. While working in industry, he gained four patents for instruments to be used for measuring magnetic and electric properties. As an academic, he chaired and developed the department of physics at Fisk University, serving from 1930 to 1941.

Elmer S. Imes was born in 1883 in Memphis, Tennessee to Elizabeth (Wallace) and Benjamin A. Imes, both of whom were college educated and had met at Oberlin College in Ohio. They married there in 1880. Benjamin earned a divinity degree at Oberlin Theological Seminary in 1880. His father was descended from free people of color who had been established in south-central Pennsylvania by the time of the Revolution. His mother was born into slavery; her family had moved to Oberlin after the American Civil War when she was a child. Imes had two younger brothers: Albert Lovejoy Imes and William Lloyd Imes. The latter became a minister and was later pastor of St. James Presbyterian Church in New York City; he held degrees from Fisk, Union Theological Seminary, and Columbia University.

Imes and his brothers attended grammar school in Oberlin, Ohio. Their parents became missionaries with the American Missionary Association and moved to the South to serve freedmen and their children. Imes completed his high school education at the Agricultural and Mechanical High School in Normal, Alabama. He graduated in 1903 from Fisk University, a historically black college, with a bachelor's degree in science.

Upon graduating from Fisk, Imes taught mathematics and physics at Georgia Normal and Agricultural Institute; now Albany State University, a historically black college in Albany, Georgia, and the Emerson Institute, which had been founded in Mobile, Alabama by the American Missionary Association. Imes returned to Fisk in 1913 as an instructor of science and mathematics. During his tenure there, Imes also earned a master's degree in science from Fisk University.

He went to the University of Michigan for additional study in physics, earning a Ph.D. in Physics in 1918. He studied under Harrison McAllister Randall. Imes became the second African American to receive a Ph.D. in physics since Edward Bouchet did so from Yale University in 1876; Imes was the first African American in the 20th century to gain this degree.

Around 1919, after moving to New York to work in industry, Imes married Nella Larsen, a nurse who became a writer. She is considered part of the Harlem Renaissance, having published short stories and two novels in the late 1920s. The couple had moved from Jersey City, New Jersey, to Harlem, where they became part of the professional and cultural society that included artists and intellectuals such as Langston Hughes and W.E.B. Du Bois, members of the black elite. Due to strains in their marriage, they divorced in 1933, after Imes had returned to Fisk University in 1929 for an academic career.

Imes’ research and doctoral thesis led to his publication of Measurements on the Near-Infrared Absorption of Some Diatomic Gases in November 1919 in the Astrophysical Journal.[4] This work was followed by a paper co-authored and presented in November 1919 jointly with Harrison M. Randall, "The Fine Structure of the Near Infra-Red Absorption Bands of HCI, HBr, and HF" at the American Physical Society; it was published in the Physical Review in February 1920. This work demonstrated for the first time that Quantum Theory could be applied to radiation in all regions of the electromagnetic spectrum, to the rotational energy states of molecules, as well as the vibration and electronic levels. Imes' work provided an early verification of Quantum Theory. It became known in Europe as well as in the United States.

Imes' work was one of the earliest applications of high resolution infrared spectroscopy and provided the first detailed spectra of molecules. This led to development of the field of study of molecular structure through infrared spectroscopy.

In the early 1920s, Imes found difficulty in securing employment in academia. Not many black colleges had physics programs and white colleges did not hire him. As a result, he became a physics consultant and researcher after completing his doctorate; he worked in physics at the Federal Engineers Development Corporation in 1918 and with the Burrows Magnetic Equipment Corporation in 1922. In 1927, Imes went to work as a research engineer at E.A. Everett Signal Supplies. During the decade that Imes worked in the scientific and materials industry, his research resulted in four patents for instruments that were used for measuring magnetic and electric properties.

In 1930, Imes returned to Fisk University, where he served as Chair of the Physics Department. Imes is credited with the academic development of the physics programs at Fisk. Many of his students went on to obtain doctoral degrees from highly ranked schools such as the University of Michigan. While at Fisk, Imes developed a course in Cultural Physics, to teach students about the history of science. In 1931, Imes was named one of the thirteen most gifted Black Americans.

In 1939, Imes returned to New York, where he conducted research as a scholar in magnetic materials at the Physics Department at New York University. He died in 1941.

Pyotr Kapitsa

Pyotr Kapitsa was a leading Soviet physicist and Nobel laureate, best known for his work in low-temperature physics.