When you squeeze one end of a tube of toothpaste out the other end, you are watching
Pascalï¿½s principle in action. The principle was first stated clearly in 1652 by Blaise
Pascal (for who the unit of pressure is named):
A change in the pressure applied to an enclosed incompressible fluid is transmitted
undiminished to every portion of the fluid to the walls of its container.
Pascalï¿½s principle put more simply, basically means that an incompressible fluid
transmits pressure. This is the basis to hydraulic lever. In a hydraulic lever, for
example, you apply a force to the left-hand piston over a given area, this force is then
transformed in to a pressure which is transmitted through the hydraulic fluid or oil.
This pressure then transforms back in to an output force over another given area for the
Answered by: Dan Summons, Physics Undergrad Student, UOS, Souhampton
'We should take care not to make intellect our god; it has powerful muscles but no personality.'