What is Vacuum fluctuation: Definition and 16 Discussions

In quantum physics, a quantum fluctuation (or vacuum state fluctuation or vacuum fluctuation) is the temporary random change in the amount of energy in a point in space, as prescribed by Werner Heisenberg's uncertainty principle. They are tiny random fluctuations in the values of the fields which represent elementary particles, such as electric and magnetic fields which represent the electromagnetic force carried by photons, W and Z fields which carry the weak force, and gluon fields which carry the strong force. Vacuum fluctuations appear as virtual particles, which are always created in particle-antiparticle pairs. Since they are created spontaneously without a source of energy, vacuum fluctuations and virtual particles are said to violate the conservation of energy. This is theoretically allowable because the particles annihilate each other within a time limit determined by the uncertainty principle so they are not directly observable. The uncertainty principle states the uncertainty in energy and time can be related by




{\displaystyle \Delta E\,\Delta t\geq {\tfrac {1}{2}}\hbar ~}
, where 1/2ħ ≈ 5,27286×10−35 Js. This means that pairs of virtual particles with energy


{\displaystyle \Delta E}
and lifetime shorter than


{\displaystyle \Delta t}
are continually created and annihilated in empty space. Although the particles are not directly detectable, the cumulative effects of these particles are measurable. For example, without quantum fluctuations the "bare" mass and charge of elementary particles would be infinite; from renormalization theory the shielding effect of the cloud of virtual particles is responsible for the finite mass and charge of elementary particles. Another consequence is the Casimir effect. One of the first observations which was evidence for vacuum fluctuations was the Lamb shift in hydrogen. In July 2020 scientists report that they, for the first time, measured that quantum vacuum fluctuations can influence the motion of macroscopic, human-scale objects by measuring correlations below the standard quantum limit between the position/momentum uncertainty of the mirrors of LIGO and the photon number/phase uncertainty of light that they reflect.

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  1. F

    I Non-wave solution to wave equation and virtual particles

    Hello everyone. The 1D wave equation is written: $$ \left( \partial_t^2/c^2 - \partial_x^2 \right) \Psi = 0$$ An electromagnetic wave or matter wave, like free electron (unnormalized here), can be written with the following wave function ##\Psi_m## of energy ## \hbar k c ##: $$ \Psi_m \propto...
  2. S

    I From a false vacuum to a true vacuum?

    In theory (please correct me if I am wrong in any point), if our vacuum were metastable (i.e. in a "false vacuum" state), it could go through a phase transition into a stable state (a "true vacuum" state). Depending on the properties of the new vacuum, fundamental forces and particles could...
  3. R

    Good literature needed (QFT topics)

    Summary:: Trying to find good books so that I can continue writing my paper about the vacuum Hello fellow physics enthusiasts, I require your support to find good and scientific literature about: Lamb Shift Vacuumpolarisation Zero point energy It can be a long source too, so don't be afraid...
  4. Y

    A Contribution of vacuum fluctuation to the self-energy of the electron

    In the book" The Quantum Theory of Radiation", Heitler derived the transverse self-energy of the electron(Chapter III, Section18, Eq.(23)) $$\frac{{{e^2}}}{{\pi m}}\int_{\text{0}}^\infty {kdk} $$ which is the energy of the electron under the action of the vacuum fluctuation of the radiation...
  5. A

    A Quantum vacuum fluctuation in BEC

    Hi, I have some problems with visualization (I'm trying to understand Jeff Steinhauer's experiment, but my questions are general). Why the quantum vacuum fluctuations are guaranteed by the underlying pointlike atoms composing a BEC? And if vacuum fluctuations generate excitations (i.e...
  6. A

    A How, and in what atoms does the Lamb shift occur?

    The Uehling potential due to vacuum polarization by virtual electron-positron pairs is said to be the dominant contribution — 205.0073 meV — to the Lamb shift between the 2P1/22P1/2 and 2S1/22S1/2 states of muonic hydrogen. In the Wikipedia page (https://en.wikipedia.org/wiki/Lamb_shift), it is...
  7. mark!

    B Was the Big Bang a quantum mechanical vacuum fluctuation?

    It has been proposed by Edward P. Tryon that the Universe may be a large scale quantum mechanical vacuum fluctuation where positive mass-energy is balanced by negative gravitational potential energy, as a consequence of the early inflationary launch of the expansion of the Universe, in which...
  8. A. Neumaier

    Insights The Vacuum Fluctuation Myth - Comments

    A. Neumaier submitted a new PF Insights post The Vacuum Fluctuation Myth Continue reading the Original PF Insights Post.
  9. F

    I Relation between quantum fluctuations and vacuum energy?

    As far as I understand it, the non-zero vacuum energy attributed to a quantum field (at each point in space-time) is precisely due to the Heisenberg uncertainty principle (and the fact that the energy of the quantum field at each space-time point is quantised). Accordingly (in order to satisfy...
  10. w0_0dy

    The big bang was a fluctuation of what?

    I have read that the total energy of the universe is zero and that the big bang might have emerged from a quantum fluctuation. Also that there is a chance (extremely low) of another big bang occurring in the quantum vacuum energy fluctuations. As far as I understand the vacuum energy / dark...
  11. H

    No problem, happy to help! Enjoy your vacation!

    I have been going through chapter 2 of Sakurai; the 1967 edition. Chapter 2 gets into the self energy of the electron, the concept of the bare mass of the electron, and vacuum fluctuations. Would these same concepts (self energy, bare mass, and vacuum fluctuations) apply to a scalar field (e g...
  12. H

    Vacuum fluctions and the Casimir Effect

    I don't recall where I saw this...but the author said that the Casimir effect experimentally proved that vacuum fluctuations exist. Does the Casimir effect really prove that or is it consistent with vacuum fluctuations? Thanks for any comments you care to make.
  13. S

    Vacuum Fluctuation: Exploring Interaction with EM Field

    recently i listened something about vacuum fluctuation.i don't know what exactly is it.but from that fluctuation is it possible to say that there is some width of the energy eigenvalue of a system where the particles are interact with em field.i don't know anything about field theory.
  14. C

    Vacuum Fluctuation Dimensional Constraints

    I understand that vacuum fluctuations can spring into and out of existence within a sufficiently short period of time, under the uncertainty constraint. However, I am currently a little confused over how this constraint is applied. 1) Does one use del E.del t = h bar (the commutation...
  15. Y

    Interpretation of vacuum fluctuation

    to preserve commutation relations in the quantized field operators (basically simple harmonic oscillator raising/lowering operators), a vacuum mode must be introduced in the case of a usual 50-50 beam splitter. thus, one has 4 modes: vacuum incident mode reflected mode transmited...
  16. S

    Exploring Vacuum Fluctuations: Particle Creation and the Casimir Effect

    [SOLVED] vacuum fluctuation I have a few questions about this topic. 1. If their is build energy in vacuum (from Heisenberg's uncertainty principle), for example: build: 10 J ==> here for: d(t)=h/(4pi)/10J There must be built a particle and an anti particle ==> particle has 5 J and...