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elementary particles

(Encyclopedia)CE5 elementary particles, the most basic physical constituents of the universe. The first subatomic particle to be discovered was the electron, identified in 1897 by J. J. Thomson. After the...

Rajasthan

(Encyclopedia)Rajasthan räˈjəstän [key], state (2001 provisional pop. 56,473,122), 132,150 sq mi (342,269 sq km), NW India, bordered on the west by Pakistan. The capital is Jaipur; other large cities are Ajmer,...

seaborgium

(Encyclopedia)seaborgium sēbôrˈgēəm [key], artificially produced radioactive chemical element; symbol Sg; at. no. 106; mass number of most stable isotope 271; m.p., b.p., sp. gr., and valence unknown. Situated...

gluon

(Encyclopedia)gluon, an elementary particle that mediates, or carries, the strong, or nuclear, force. In quantum chromodynamics (QCD), the quantum field theory of strong interactions, the interaction of quarks (to ...

Decatur

(Encyclopedia)Decatur. 1 City (2020 pop. 57,938), seat of Morgan co., N Ala., on the Tennessee River; inc. 1826. It has shipyards, port traffic, and diverse ...

Feynman, Richard Phillips

(Encyclopedia)Feynman, Richard Phillips fīnˈmən [key], 1918–88, American physicist, b. New York City, B.S. Massachusetts Institute of Technology, 1939, Ph.D. Princeton, 1942. From 1942 to 1945 he worked on the...

pump

(Encyclopedia)pump, device to lift, transfer, or increase the pressure of a fluid (gas or liquid) or to create a vacuum in an enclosed space by the removal of a gas (see vacuum pumps under vacuum). The centrifugal ...

hygrometer

(Encyclopedia)hygrometer hīgrŏmˈətər [key], instrument used to measure the moisture content of a gas, as in determining the relative humidity of air. The temperature at which dew or frost forms is a measure of...

stellar populations

(Encyclopedia)stellar populations, two broadly contrasting distributions of star types that are characteristic of different parts of a galaxy. Population I stars are young, recently formed stars, whereas population...

Tahiti

(Encyclopedia)Tahiti tähēˈtē [key], island (2002 pop. 169.674), South Pacific, in the Windward group of the Society Islands, French Polynesia. The capital is Papeete. Tahiti is the largest (402 sq mi/1,041 sq k...