绝对真空

绝对真空（英语：Absolute vacuum），亦作完美真空（Perfect vacuum）^[1]，是指一个理论上没有任何物质的封闭的空间，是一种理论上理想的真空状态（气压＝0），以目前的科技尚难达到。

在压力测量领域，由于现代许多高精密度的产品在制造过程中的某些阶段必需使用程度不一的真空才能制造，绝对真空是真空技术中按照压力的高低而区分的五个级别的最高级别，内里只有0 Torr，比其次一级的超高真空（Ultra-High Vacuum）所要求的10^-7 Torr以下还要严谨。

另外，在古典电磁学的定义，完美真空是电磁效应的一个标准参考媒介^[2][3]，所以亦有作者把这种真空状态称为“古典真空”^[2]，以与量子力学其他有关真空的术语如“量子电动力学真空”（QED vacuum）或“量子色动力学真空”（QCD vacuum）等透过可以产生短暂的虚粒子密度和相对介电常数与相对磁导率两项并不统一的真空波动环境^[4][5][6]区分。

参考资料

1. Definition of Absolute Vacuum [绝对真空的定义]. about.com. [2014-03-29]. （原始内容存档于2014-07-10） （英语）.
2. Werner S. Weiglhofer. § 4.1 The classical vacuum as reference medium. Werner S. Weiglhofer and Akhlesh Lakhtakia, eds (编). Introduction to complex mediums for optics and electromagnetics. SPIE Press. 2003: 28, 34. ISBN 978-0-8194-4947-4.
3. Tom G. MacKay. Electromagnetic Fields in Linear Bianisotropic Mediums. Emil Wolf (编). Progress in Optics, Volume 51. Elsevier. 2008: 143 [2014-04-01]. ISBN 978-0-444-52038-8. （原始内容存档于2021-04-14）.
4. Gilbert Grynberg, Alain Aspect, Claude Fabre. Introduction to Quantum Optics: From the Semi-Classical Approach to Quantized Light. Cambridge University Press. 2010: 341 [2014-04-01]. ISBN 0-521-55112-9. （原始内容存档于2021-04-14）. ...deals with the quantum vacuum where, in contrast to the classical vacuum, radiation has properties, in particular, fluctuations, with which one can associate physical effects.
5. For a qualitative description of vacuum fluctuations and virtual particles, see Leonard Susskind. The cosmic landscape: string theory and the illusion of intelligent design. Little, Brown and Co. 2006: 60 ff [2014-04-01]. ISBN 0-316-01333-1. （原始内容存档于2021-04-14）.
6. The relative permeability and permittivity of field-theoretic vacuums is described in Kurt Gottfried, Victor Frederick Weisskopf. Concepts of particle physics, Volume 2. Oxford University Press. 1986: 389 [2014-04-01]. ISBN 0-19-503393-0. （原始内容存档于2021-04-14）. and more recently in John F. Donoghue, Eugene Golowich, Barry R. Holstein. Dynamics of the standard model. Cambridge University Press. 1994: 47 [2014-04-01]. ISBN 0-521-47652-6. （原始内容存档于2021-04-14）. and also R. Keith Ellis, W. J. Stirling, B. R. Webber. QCD and collider physics. Cambridge University Press. 2003: 27–29 [2014-04-01]. ISBN 0-521-54589-7. （原始内容存档于2021-04-14）. Returning to the vacuum of a relativistic field theory, we find that both paramagnetic and diamagnetic contributions are present. QCD vacuum is paramagnetic, while QED vacuum is diamagnetic. See Carlos A. Bertulani. Nuclear physics in a nutshell. Princeton University Press. 2007: 26 [2014-04-01]. ISBN 0-691-12505-8. （原始内容存档于2021-04-14）.

参看

• 真空
• 真空状态 - 电磁学