Vacuum (disambiguation)

This disambiguation page lists articles associated with the same or a similar title.

• Vacuum (science) [r]: A realizable vacuum with a gaseous pressure that is much less than atmospheric. ^[e]
• Vacuum (partial) [r]: A realizable vacuum with a gaseous pressure that is much less than atmospheric. ^[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] The term classical vacuum as used in classical electromagnetism refers to a reference state devoid of all particles, that is, a state with zero pressure obtainable only in principle, and not in practice.
• 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 (political) [r]: A situation in which no power is dominant, and the power balance is in flux. ^[e]