Rarefaction is the reduction of a medium's density, or the opposite of compression. Compression in material science, physics or structural engineering, is the stress state of materials where the volume tends to decrease (compaction). ...

A natural example of this is as a phase in a sound wave or phonon. Half of a sound wave is made up of the compression of the medium, and the other half is the decompression or rarefaction of the medium. Waves with the same phase Waves with different phases The phase of a wave relates the position of a feature, typically a peak or a trough of the waveform, to that same feature in another part of the waveform (or, which amounts to the same, on a second waveform). ... This article is about compression waves. ... The phonon is the acoustic analogy to the photon. ... This article is about compression waves. ... The word medium (from Latin, in which it means, the one in the middle) can have different meanings in different contexts. ...

Another natural example of rarefaction is in the layers of our atmosphere. Because what constitutes our atmosphere has mass, it is definite that most of the atmospheric matter will be nearer to the Earth. Therefore, air at higher layers of the atmosphere is considered to have less pressure, or is rarefied in relation to air at lower layers. Layers of Atmosphere (NOAA) Earths atmosphere is a layer of gases surrounding the planet Earth and retained by the Earths gravity. ... Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... Matter is commonly referred to as the substance of which physical objects are composed. ... Pressure (symbol: p) is the force per unit area acting on a surface in a direction perpendicular to that surface. ...

Rarefaction can be easily observed by compressing a spring and releasing it. Springs A spring is a flexible elastic object used to store mechanical energy. ...

Rarefaction is also frequently used in ecology and especially to standardize species richness. Rarefaction allows the calculation of the species richness for a given number of sampled individuals and allows the construction of so called rarefaction curves. This curves plot the number of species in function of the number of individuals sampled. In case of a steep slope a large fraction of the species diversity is not sampled, if the part of the curve is already becoming flat, a reasonable number of individuals is sampled and more intensive sampling will probably only yield a small number of additional species (if any).

rarefaction (tm) is also a Brooklyn, New York based, goth-influenced rock band, comprised of Mad Tristan (prima voce) & Jerold H. (instruments/vox). Gothic woman, trad style, with spikes and piercings This article is about the contemporary goth/gothic subculture. ...

Rarefaction is also a record label specializing in creating sound and sound effect libraries.