==أمثلة في الطبيعة==
يحدث تخلخل للهواء في [[جو الأرض]]. نظرا لأن أغلبية [[كتلة]] الهواء تكون موجودة بالقرب من سطح الأرض أو البحر ، هذا بسبب [[الجاذبية]] .
A natural example of rarefaction occurs in the layers of [[Earth's atmosphere]]. Because the atmosphere has [[mass]], most atmospheric [[matter]] is nearer to the Earth due to the Earth's [[gravitation]]. Therefore, air at higher layers of the atmosphere is less dense, or ''rarefied'', relative to air at lower layers. Thus rarefaction can refer either to a reduction in density over space at a single point of time, or a reduction of density over time for one particular area.
Rarefaction can be easily observed by compressing a [[Spring (device)|spring]] and releasing it. Instead of seeing compressed loops seeming to move through the spring, spaced-out loops move through it: rarefaction waves.