"Since the virtual photons in between two parallel metal plates placed a short distance apart can exist only when they can form a standing wave, there are fewer photons in each cubic centimeter of vacuum between the plates than there are in the vacuum outside. So, in effect, there is an excess pressure from outside pushing the plates together. This is known as Casimir effect (see Figure 12-03f). The resulting force is very small, but it has been measured (for plates separated by gaps of a few nanometers), proving that quantum fluctuations of the vacuum are a real phenomenon."
"All atoms and molecules -- even inert-gas such as those of helium and argon -- exhibit weak, short-range attractions for one another due to van der Waals forces. These forces are responsible for the condensation of gases into liquids and the freezing of liquids into solids. Such familiar aspects of the behavior of matter in bulk as friction, surface tension, viscosity, adhesion, cohesion, and so on also arise from van der Waals forces.
Quantized Vacuum?
Frederick
