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virtual observatory

(Encyclopedia)virtual observatory, a collection of integrated astronomical data archives and software tools that utilize computer networks to create an environment in which research can be conducted. Several countr...

chlorophyll

(Encyclopedia)CE5 chlorophyll klôrˈəfĭlˌ [key], green pigment that gives most plants their color and enables them to carry on the process of photosynthesis. Chemically, chlorophyll has several similar forms...

Kelvin temperature scale

(Encyclopedia)Kelvin temperature scale, a temperature scale having an absolute zero below which temperatures do not exist. Absolute zero, or 0K, is the temperature at which molecular energy is a minimum, and it c...

stereochemistry

(Encyclopedia)stereochemistry, study of the three-dimensional configuration of the atoms that make up a molecule and the ways in which this arrangement affects the physical and chemical properties of the molecule. ...

Archimedes

(Encyclopedia)Archimedes ärkĭmēˈdēz [key], 287–212 b.c., Greek mathematician, physicist, and inventor. He is famous for his work in geometry (on the circle, sphere, cylinder, and parabola), physics, mechanic...

Swinburne, Algernon Charles

(Encyclopedia)Swinburne, Algernon Charles, 1837–1909, English poet and critic. His poetry is noted for its vitality and for the music of its language. After attending Eton (1849–53) and Oxford (1856–60) he se...

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 ...

nutrition

(Encyclopedia)nutrition, study of the materials that nourish an organism and of the manner in which the separate components are used for maintenance, repair, growth, and reproduction. Nutrition is achieved in vario...

Dürrenmatt, Friedrich

(Encyclopedia)Dürrenmatt, Friedrich frēˈdrĭkh dürˈənmät [key], 1921–90, Swiss playwright and novelist. Dürrenmatt's writings depict a world both comic and grotesque. As a young German-speaking playwright...

cylinder

(Encyclopedia)CE5 Cylinder cylinder, in mathematics, surface generated by a line moving parallel to a given fixed line and continually intersecting a given fixed curve called the directrix; each line of the fam...