Editing Anisotropy (section)

===Physics===<!-- This section is linked from [[Birefringence]] -->
[[File:Plasma-lamp 2.jpg|thumb|300px|right|A [[plasma globe]] displaying the nature of [[plasma (physics)|plasmas]], in this case, the phenomenon of "filamentation"]]

[[Physicist]]s from [[University of California, Berkeley]] reported about their detection of the cosmic anisotropy in [[cosmic microwave background radiation]] in 1977. Their experiment demonstrated the [[Doppler shift]] caused by the movement of the earth with respect to the [[Big Bang|early Universe]] matter, the source of the radiation.<ref>{{cite web |title=Detection of Anisotropy in the Cosmic Blackbody Radiation |publisher=[[Lawrence Berkeley Laboratory]] and [[Space Sciences Laboratory]], [[University of California, Berkeley]] |author1=Smoot G. F. |author2=Gorenstein M. V. |author3-link=Richard A. Muller |author3=Muller R. A. |name-list-style=amp |date=5 October 1977 |url=https://muller.lbl.gov/COBE-early_history/anisotropy-PRL.pdf |access-date=15 September 2013 |url-status=live |archive-url=https://ghostarchive.org/archive/20221009/https://muller.lbl.gov/COBE-early_history/anisotropy-PRL.pdf |archive-date=2022-10-09}}</ref> Cosmic anisotropy has also been seen in the alignment of galaxies' rotation axes and polarization angles of quasars.{{fact|date=March 2025}}

Physicists use the term anisotropy to describe direction-dependent properties of materials. [[Magnetic anisotropy]], for example, may occur in a [[plasma (physics)|plasma]], so that its magnetic field is oriented in a preferred direction. Plasmas may also show "filamentation" (such as that seen in [[lightning]] or a [[plasma globe]]) that is directional.{{fact|date=March 2025}}

An ''anisotropic liquid'' has the fluidity of a normal liquid, but has an average structural order relative to each other along the molecular axis, unlike water or [[chloroform]], which contain no structural ordering of the molecules. [[Liquid crystal]]s are examples of anisotropic liquids.{{fact|date=March 2025}}

Some materials [[heat conduction|conduct heat]] in a way that is isotropic, that is independent of spatial orientation around the heat source.  Heat conduction is more commonly anisotropic, which implies that detailed geometric modeling of typically diverse materials being thermally managed is required. The materials used to transfer and reject heat from the heat source in [[electronics]] are often anisotropic.<ref name="Nature8April2013">{{cite journal |last1=Tian |first1=Xiaojuan |last2=Itkis |first2=Mikhail E |last3=Bekyarova |first3=Elena B |last4=Haddon |first4=Robert C |title=Anisotropic Thermal and Electrical Properties of Thin Thermal Interface Layers of Graphite Nanoplatelet-Based Composites |journal=Scientific Reports |volume=3 |pages=1710 |date=8 April 2013 |doi=10.1038/srep01710 |pmc=3632880 |bibcode=2013NatSR...3.1710T}}</ref>

Many [[crystal]]s are anisotropic to [[light]] ("optical anisotropy"), and exhibit properties such as [[birefringence]]. [[Crystal optics]] describes light propagation in these media. An "axis of anisotropy" is defined as the axis along which isotropy is broken (or an axis of symmetry, such as normal to crystalline layers). Some materials can have multiple such [[optic axis of a crystal|optical axes]].{{fact|date=March 2025}}