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critical mass

noun
1.
Physics. the amount of a given fissionable material necessary to sustain a chain reaction at a constant rate.
2.
an amount necessary or sufficient to have a significant effect or to achieve a result:
a critical mass of popular support.
Origin of critical mass
1940-1945
1940-45
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the Web for critical mass
Contemporary Examples
Historical Examples
  • Claire always knew what to do when his temper started climbing to critical mass.

    Null-ABC Henry Beam Piper and John Joseph McGuire
  • What we need is some publicity for it, some critical mass, and some way that we can get ordinary people involved.

  • Too well shielded for the blast to get them, but the heat melted the fissionables down to critical mass.

    Day of the Moron Henry Beam Piper
  • The plutonium bomb worked by compressing the plutonium into a critical mass which sustains a chain reaction.

    Trinity [Atomic test] Site White Sands Missile Range Public Affairs Office
  • First, two or more pieces of plutonium large enough to form a critical mass.

    Rip Foster in Ride the Gray Planet Harold Leland Goodwin
British Dictionary definitions for critical mass

critical mass

noun
1.
the minimum mass of fissionable material that can sustain a nuclear chain reaction
2.
the minimum amount of money or number of people required to start or sustain an operation, business, process, etc: the critical mass for a subscription digital sports channel
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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critical mass in Science
critical mass  
  1. The smallest mass of a fissionable material that will sustain a nuclear chain reaction.

  2. The amount of matter needed to generate sufficient gravitational force to halt the current expansion of the universe. See also big bang, big crunch.


The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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critical mass in Culture

critical mass definition


In physics, the amount of material that must be present before a chain reaction can sustain itself.

Note: The term critical mass is used to refer generally to the minimum amount of something needed to produce a given effect: “The town needs a critical mass of industry to attract more business.”
The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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critical mass in Technology


In physics, the minimum amount of fissionable material required to sustain a chain reaction. Of a software product, describes a condition of the software such that fixing one bug introduces one plus epsilon bugs. (This malady has many causes: creeping featurism, ports to too many disparate environments, poor initial design, etc.) When software achieves critical mass, it can never be fixed; it can only be discarded and rewritten.
[Jargon File]
(1994-12-23)

The Free On-line Dictionary of Computing, © Denis Howe 2010 http://foldoc.org
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