# Solar constant

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Solar constant
Constant Con"stant, n. 1. That which is not subject to change; that which is invariable. [1913 Webster]

2. (Math.) A quantity that does not change its value; -- used in countradistinction to {variable}. [1913 Webster]

3. (Astron.) A number whose value, when ascertained (as by observation) and substituted in a general mathematical formula expressing an astronomical law, completely determines that law and enables predictions to be made of its effect in particular cases. [Webster 1913 Suppl.]

4. (Physics) A number expressing some property or condition of a substance or of an instrument of precision; as, the dielectric constant of quartz; the collimation constant of a transit instrument. [Webster 1913 Suppl.]

5. (Computers) a data structure that does not change during the course of execution of a program. It may be a number, a string, or a more complex data structure; -- contrasted with {variable}. [PJC]

{Aberration constant}, or {Constant of aberration} (Astron.), a number which by substitution in the general formula for aberration enables a prediction to be made of the effect of aberration on a star anywhere situated. Its value is 20[sec].47.

{Absolute constant} (Math.), one whose value is absolutely the same under all circumstances, as the number 10, or any numeral.

{Arbitrary constant}, an undetermined constant in a differential equation having the same value during all changes in the values of the variables.

{Gravitation constant} (Physics), the acceleration per unit of time produced by the attraction of a unit of mass at unit distance. When this is known the acceleration produced at any distance can be calculated.

{Solar constant} (Astron.), the quantity of heat received by the earth from the sun in a unit of time. It is, on the C. G. S. system, 0.0417 small calories per square centimeter per second. --Young. [Webster 1913 Suppl.]

{Constant of integration} (Math.), an undetermined constant added to every result of integration. [1913 Webster + Webster 1913 Suppl.]

The Collaborative International Dictionary of English. 2000.

### Look at other dictionaries:

• solar constant — n. the average amount of solar radiation received normally by a unit area just outside the earth s atmosphere, equal to c. 1.37 x 106 ergs per cm2 per second …   English World dictionary

• solar constant — the average rate at which radiant energy is received from the sun by the earth, equal to 1.94 small calories per minute per square centimeter of area perpendicular to the sun s rays, measured at a point outside the earth s atmosphere when the… …   Universalium

• solar constant — The solar constant (as defined for the planet Earth) is the power collected at the top of the atmosphere by a unit area perpendicular to the light path. In practice, the unit area is 1 m squared (m2). Its value is about 1.98 calories per minute… …   Aviation dictionary

• solar constant —   The strength of sunlight; 1353 watts per square meter in space and about 1000 watts per square meter at sea level at the equator at solar noon.   Solar Electric Glossary …   Energy terms

• solar constant — noun Date: 1869 the quantity of radiant solar energy received at the outer layer of the earth s atmosphere that has a mean value of 1370 watts per square meter …   New Collegiate Dictionary

• solar constant — noun The amount of incoming solar radiation per unit area, measured on the outer surface of Earths atmosphere, in a plane perpendicular to the rays …   Wiktionary

• Solar Constant —   The average amount of solar radiation that reaches the earth s upper atmosphere on a surface perpendicular to the sun s rays; equal to 1353 Watts per square meter or 492 Btu per square foot …   Energy terms

• Solar constant —   The average amount of solar radiation that reaches the earth s upper atmosphere on a surface perpendicular to the sun s rays; equal to 1353 Watts per square meter or 492 Btu per square foot.   U.S. Dept. of Energy, Energy Information… …   Energy terms

• solar constant — so′lar con′stant n. astron. the average rate at which solar radiant energy is received by the earth: 1.94 small calories per minute per sq. cm …   From formal English to slang

• solar constant — noun the rate at which radiant solar energy is received at the outer layer of the earth s atmosphere • Hypernyms: ↑rate …   Useful english dictionary