Vacuum energy

Using the upper limit of the cosmological constant, the vacuum energy of free space has been estimated to be 10−9 joules (10−2 ergs), or ~5 GeV per cubic meter.

[3] However, in quantum electrodynamics, consistency with the principle of Lorentz covariance and with the magnitude of the Planck constant suggests a much larger value of 10113 joules per cubic meter.

Note that this method of computing vacuum energy is mathematically equivalent to having a quantum harmonic oscillator at each point and, therefore, suffers the same renormalization problems.

[citation needed] Additional contributions to the vacuum energy come from spontaneous symmetry breaking in quantum field theory.

In 1948, Dutch physicists Hendrik B. G. Casimir and Dirk Polder predicted the existence of a tiny attractive force between closely placed metal plates due to resonances in the vacuum energy in the space between them.

Essentially, a non-zero vacuum energy is expected to contribute to the cosmological constant, which affects the expansion of the universe.

The study derived a mathematical framework that uses the field strength of vacuum energy as an indicator of the bulk (spacetime) resistance to localized curvature.

However, the outcomes of these experiments have shown significant inconsistencies, making it difficult to reach a definitive conclusion regarding the value of G. This lack of consensus has puzzled scientists and called for alternative explanations.

These conditions aim to achieve consistent outcomes in precision measurements of G. The ultimate goal of such experiments is to either falsify or provide confirmations to the proposed theoretical framework.

The significance of exploring the field strength of vacuum energy lies in its potential to revolutionize our understanding of gravity and its interactions.

In 1934, Georges Lemaître used an unusual perfect-fluid equation of state to interpret the cosmological constant as due to vacuum energy.

However, the exact nature of the particles (or fields) that generate vacuum energy, with a density such as that required by inflation theory, remains a mystery.

The Casimir effect is a physical force affecting macro-size objects and arises from vacuum energy, which are quantized oscillations in the electromagnetic field permeating every microscopic crevice of the Universe that give that field a non-zero energy. When two conductive flat plates of the same material are less than about 1000 nanometers apart (about twice the width of a common bacterium), they begin to form an electromagnetic cavity that excludes larger-wavelength components of vacuum energy. This reduces the energy between the plates, creating a pressure imbalance that pushes them together. Here, the gap permits only excitations with wavelengths no greater those shown in green color to pop into existence between the plates, excluding yellow, orange, red wavelengths.