Part of the Casswiki article series Natural science
The term “zero point field” refers to the idea that vacuum is in fact filled with electromagnetic waves of all frequencies but these waves are not normally measurable because they cancel each other out. For any wave of a given frequency and amplitude, there exists another wave of the same frequency, amplitude and plane of polarization but of the opposite phase. When adding up all these waves, we get zero amplitude across all frequencies.
The same idea is found in the notion of vacuum being a boiling sea of virtual particle/antiparticle pairs that constantly materialize and then annihilate each other, fluctuating as it were between a particle and wave manifestation. Again, this is normally undetectable because the waves thus emitted cancel out and the particles annihilate by reacting with their antiparticles, thus returning into the electromagnetic wave manifestation.
The experimental validation of the concept of zero point energy is found with the Casimir effect. This effect is seen when two very smooth metal plates are placed parallel to each other at a distance in the micron range. The plates are pressed together with a force proportional to the inverse of the fourth power of their distance. This can be explained by the close proximity of the plates not leaving space between them for waves whose wavelength is less than the intervening distance. The closer the plates are, the more frequencies waves are excluded from the intervening space. Waves of these frequencies do however push against the plates from either side, thus amounting to unbalanced radiation pressure, pressing the plates together.
While the Casimir effect is a convincing demonstration of the zero point field’s existence, it does not allow extracting energy from this field. Any energy that may be obtained by the plates being pressed together must be expended to get them to separate again. The estimates on the energy density of the zero point field vary wildly but according to some this would be well in excess of what is found with nuclear reactions.
Much speculation has gone into tapping the zero point field as a source of energy, but none of the publicly known work in the field of “free energy” stands to scientific scrutiny.