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Kepler's laws

(Encyclopedia)CE5 Schematic representation of Kepler's second law: The areas ABF and A′B′F′ are equal and are swept out in equal intervals of time by a planet orbiting around the sun (at F). Kepler's laws...

Eden, Anthony, 1st earl of Avon

(Encyclopedia)Eden, Anthony, 1st earl of Avon āˈvən [key], 1897–1977, British statesman. After service in World War I ...

binocular

(Encyclopedia)CE5 Binocular binocular, small optical instrument consisting of two similar telescopes mounted on a single frame so that separate images enter each of the viewer's eyes. As with a single telescope...

strength of materials

(Encyclopedia)strength of materials, measurement in engineering of the capacity of metal, wood, concrete, and other materials to withstand stress and strain. Stress is the internal force exerted by one part of an e...

sundial

(Encyclopedia)sundial, instrument that indicates the time of day by the shadow, cast on a surface marked to show hours or fractions of hours, of an object on which the sun's rays fall. Although any object whose sha...

paleomagnetism

(Encyclopedia)paleomagnetism, study of the intensity and orientation of the earth's magnetic field as preserved in the magnetic orientation of certain minerals found in rocks formed throughout geologic time. Paleom...

momentum

(Encyclopedia)momentum mōmĕnˈtəm [key], in mechanics, the quantity of motion of a body, specifically the product of the mass of the body and its velocity. Momentum is a vector quantity; i.e., it has both a magn...

helicopter

(Encyclopedia)helicopter, type of aircraft in which lift is obtained by means of one or more power-driven horizontal propellers called rotors. When the rotor of a helicopter turns it produces reaction torque which ...

foot, in anatomy

(Encyclopedia)CE5 Foot foot, in anatomy, terminal part of the land vertebrate leg. The term is also applied to any invertebrate appendage used either for locomotion or attachment, e.g., the legs of insects and ...

Geiger counter

(Encyclopedia)Geiger counter or Geiger-Müller (G-M) counter gīˈgər-mŭlˈər, –myo͞oˈlər [key], instrument for the detection and quantitative determination of ionizing radiation such as the alpha and beta ...