What is Young–Laplace equation?
[[File:Surface_tension_Attension_Theta.png|alt=Surface tension with the pendant drop method.|thumb|562x562px|Optical tensiometers use the Young-Laplace equation to determine liquid surface tension automatically based on pendant droplet shape.]] In [[physics]], the '''Young–Laplace equation''' ({{IPAc-en|l|ə|ˈ|p|l|ɑː|s}}) is a nonlinear [[partial differential equation]] that describes the [[capillary pressure]] difference across the interface between two [[Fluid statics|static fluids]], such as [[water]] and [[air]]. This difference is due to the phenomenon of [[surface tension]] or [[wall tension]]. Wall tension can only be used for very thin walls. The Young–Laplace equation relates the [[pressure]] difference to the shape of the surface or wall. It is very important in the study of static [[Capillary surface|capillary surfaces]]. In physiology it is known as '''Laplace's law'''. It is used to describe the pressure inside hollow organs. The equation is named after [[Thomas Young (scientist)|Thomas Young]], who developed the qualitative theory of surface tension in 1805, and [[Pierre-Simon Laplace]] who completed the mathematical description in the following year. It is sometimes also called the Young–Laplace–Gauss equation: [[Carl Friedrich Gauss]] unified the work of Young and Laplace in 1830. Gauss derived both the differential equation and boundary conditions using [[Johann Bernoulli]]'s [[virtual work]] principles.<ref>{{cite web|url=http://www.ams.org/notices/199907/fea-finn.pdf|title=Capillary Surface Interfaces|author=Robert Finn|year=1999|publisher=[[American Mathematical Society|AMS]]}}</ref> == References == {{reflist}} [[Category:Equations of physics]]