Vacuum (disambiguation): Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>John R. Brews
(disambiguation page)
imported>Howard C. Berkowitz
(Political vacuum, and finishing the lemmas by making the red main page)
Line 1: Line 1:
{{disambig}}
{{disambig}}


{{r|Vacuum (partial)}} The term ''partial vacuum'' refers to real vacuums which can be obtained and observed.
{{r|Vacuum (partial)}}  
{{r|Vacuum (quantum electrodynamic)}} The term ''quantum electrodynamic vacuum'', or QED, refers to refers to the ground state of the [[Electromagnetic wave|electromagnetic field]], which is subject to fluctuations about a dormant zero average-field condition.
{{r|Vacuum (quantum electrodynamic)}}
{{r|Vacuum (partial)}} The term ''partial vacuum'' refers to real vacuums which can be obtained and observed.
{{r|Vacuum (classical)}}  
{{r|Vacuum (classical)}} The term classical vacuum refers to a perfect vacuum (or [[free space (electromagnetism)|free space]]) that is completely empty of matter having a gaseous pressure of exactly zero; as zero pressure cannot be attained in practice, this situation an idealization useful as a reference state, but is not realizable.
{{r|Vacuum (political)}}

Revision as of 13:03, 3 December 2010

This disambiguation page lists articles associated with the same or a similar title.
  • Vacuum (partial) [r]: A realizable vacuum with a gaseous pressure that is much less than atmospheric. [e]
  • Vacuum (quantum electrodynamic) [r]: The term quantum electrodynamic vacuum, or QED vacuum, refers to the ground state of the electromagnetic field, which is subject to fluctuations about a dormant zero average-field condition. [e]
  • Vacuum (classical) [r]: The term classical vacuum as used in classical electromagnetism and in the definition of the SI units refers to an ideal reference medium devoid of all particles, with ideal properties. These ideal properties include: independence from field strengths, direction, frequency, or polarization, and from temperature. [e]
  • Vacuum (political) [r]: A situation in which no power is dominant, and the power balance is in flux. [e]