Hubble's constant

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Hub·ble's constant

A ratio used in Hubble's law to express the rate of apparent expansion of the universe, equal to the velocity at which a typical galaxy is receding from Earth divided by its distance from Earth, approximately 71 kilometers per second per megaparsec.

[After Edwin Powell Hubble.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Hubble's Constant

In 1924, Edwin P. Hubble discovered that the farther away a galaxy is, the faster its apparent speed. The speed-to-distance ratio is the constant, now measured at 30–60 mi/sec (50–100 km/sec) per million parsecs.
Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.Hubble's constant - (cosmology) the ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer; the Hubble constant is not actually a constant, but is regarded as measuring the expansion rate today
cosmogeny, cosmogony, cosmology - the branch of astrophysics that studies the origin and evolution and structure of the universe
constant - a number representing a quantity assumed to have a fixed value in a specified mathematical context; "the velocity of light is a constant"
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
In fitting the Big Bang model universe to concord the observed Hubble's constant and the density of baryon matter two additional physically problematic quantities were introduced, first the presence of dark matter in addition to baryonic matter in the celestial bodies and interstellar space was proposed, and thereafter enigmatic impelling dark energy, described via a newly introduced cosmological constant, was suggested to play the role of observationally lacking matter and to explain the dynamic effects in the universe.
In such a case, the age of universe simply equals the inverse of Hubble's constant (t = [H.sup.-1]).
But tell me, what isn't being said when in the April 23 issue you report the value of Hubble's constant to be 70.4 (+1.3/-1.4), after having reported in a previous issue (SN: 4/9/11, p.
From Plato's erroneous promulgation that the planets have circular orbits to calculation in 2003 of Hubble's constant, Fraser (history and philosophy of science and technology, U.
"Hubble's constant" profoundly effected cosmology (study of the universe).