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specific gravity

(Encyclopedia)specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the t...

specific heat

(Encyclopedia)specific heat, ratio of the heat capacity of a substance to the heat capacity of a reference substance, usually water. Heat capacity is the amount of heat needed to change the temperature of a unit ma...

gravity

(Encyclopedia)gravity: see gravitation.

center of gravity

(Encyclopedia)center of gravity: see center of mass. ...

hydrometer

(Encyclopedia)hydrometer hīdrŏmˈətər [key], device used to determine directly the specific gravity of a liquid. It usually consists of a thin glass tube closed at both ends, with one end enlarged into a bulb t...

pitchblende

(Encyclopedia)pitchblende pĭchˈblĕndˌ [key], dark, lustrous, heavy mineral, a source of radium and uranium. Largely natural uranium oxides, triuranium octaoxide (U3O8) and uranium dioxide (UO2), it usually cont...

‘Oumuamua

(Encyclopedia)‘Oumuamua ōmo͞oˈəmo͞oˈə [key], officially 1I/2017 U1 (‘Oumuamua), interstellar object, the first to be discovered in the solar system. Highly variable in brightness, it also is highly and u...

separator, cream

(Encyclopedia)separator, cream, dairy machine used to separate fresh whole milk into cream and skim milk. Formerly the separation was made by the gravity method, allowing the cream to rise to the top of a pan and t...

gravitation

(Encyclopedia)gravitation, the attractive force existing between any two particles of matter. The term gravitygravity is commonly used synonymously with gravitation, but in correct usage a definite distinction is...

fifth force

(Encyclopedia)fifth force, postulated fifth basic force of nature (the four known forces of nature are gravity, electromagnetism, and the strong and weak interactions). Proposed in 1986 to account for gravitational...