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birth defects

(Encyclopedia)birth defects, abnormalities in physical or mental structure or function that are present at birth. They range from minor to seriously deforming or life-threatening. A major defect of some type occurs...

nucleus, in physics

(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...

neutrino astronomy

(Encyclopedia)neutrino astronomy, study of stars by means of their emission of neutrinos, fundamental particles that result from nuclear reactions and are emitted by stars along with light. Approximately 100 billio...

Rutherford, Ernest Rutherford, 1st Baron

(Encyclopedia)Rutherford, Ernest Rutherford, 1st Baron, 1871–1937, British physicist, b. New Zealand. Rutherford left New Zealand in 1895, having earned three degrees from the Univ. of New Zealand but having fail...

ozone

(Encyclopedia)ozone ōˈzōn [key], an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a dens...

solar wind

(Encyclopedia)solar wind, stream of ionized hydrogen—protons and electrons—with an 8% component of helium ions and trace amounts of heavier ions that radiates outward from the sun at high speeds. The continuous...

ion, in chemistry

(Encyclopedia)ion, atom or group of atoms having a net electric charge. Ionization has many applications. Vapor lamps and fluorescent lamps take advantage of the light given off when positive ions recombine with ...

SETI

(Encyclopedia)SETI sĕtˈē [key] [Search for ExtraTerrestrial Intelligence], name given to a series of independent programs to detect radio signals from civilizations beyond the solar system. Modern SETI efforts c...

Gauss, Carl Friedrich

(Encyclopedia)Gauss, Carl Friedrich kärl frēˈdrĭkh gous [key], born Johann Friederich Carl Gauss, 1777–1855, German mathematician, physicist, and astronomer. Gauss was educated at the Caroline College, Brunsw...

Manhattan Project

(Encyclopedia)Manhattan Project, the wartime effort to design and build the first nuclear weapons (atomic bombs). With the discovery of fission in 1939, it became clear to scientists that certain radioactive materi...