If virtual particles arises all the time, everywhere, wouldn’t an virtual electron-positron pair arise near an real electron; the virtual positron annihilate the real electron (as opposed to the virtual one), then the virtual electron takes the place of the real electron and becomes real itself?

Thus what is more permanent in a sense are the quantum information of the electron, as the electron which replaces the old one very quickly gets replaced itself. And in quantum physics, we calculate and represent these fundamental particles via their quantum information, it’s not possible to tag individual electrons to see if they appear or disappear very rapidly to see if they get replaced by virtual electrons all the time.

So is this possible that real particles get replaced all the time, but we wouldn't know any better? (No way to tell from experiments.) Or is there a real effect which we can calculate if they interact like this? If they do not interact like this, what's preventing this interaction? What conservation law or laws of physics is preventing this seemingly logical, should happen interaction?

P.S. take note that I am not referring the the middle part of Feymann diagram when I said virtual particles, but specifically pair production virtual particles which interacts with a real one.

  • $\begingroup$ I'm confused. Virtual particles are always internal lines in a Feynman diagram. $\endgroup$
    – jinawee
    Jan 15, 2020 at 18:58
  • $\begingroup$ Did you read up on what virtual particles are? en.wikipedia.org/wiki/Virtual_particle $\endgroup$
    – user234190
    Jan 15, 2020 at 18:59
  • $\begingroup$ The word "virtual" is not used on the page on pair production. en.wikipedia.org/wiki/Pair_production $\endgroup$
    – user234190
    Jan 15, 2020 at 19:00
  • $\begingroup$ what is an "individual" electron? $\endgroup$
    – JEB
    Jan 15, 2020 at 19:40
  • $\begingroup$ Sorry pair production is not the right term, it's the pair of virtual particles and its anti to borrow energy from the vacuum and disappear again, according to the constraint of time energy uncertainty principle. $\endgroup$ Jan 18, 2020 at 4:27

1 Answer 1


If you mean the representation of the vacuum as loops of annihilating particle antiparticle pairs, the basic rule which does not allow any real four vectors for these particles is conservation of energy.

These loops are important for corrections in interactions when there are incoming four vectors and outgoing four vectors, and yes, they are important corrections to the calculations. They are also used in the Casimir effect so there is a measurable effect.

And in quantum physics, we calculate and represent these fundamental particles via their quantum information

Not really, we use quantum field theory which is a system where all the particles in the particle table fill the whole space time with a field,an electron field, a neutrino_electron field etc, and creation and annihilation operators generate the particles. They act on the fields, which mathematically are the plane wave solutions of the corresponding differential equations, Dirac for electrons, and the operators are differentials operating on the plane waves. It is the calculation system which the Feynman diagrams economically represent and lead to calculations of scattering interactions and decays.

  • $\begingroup$ So yes or no, do these virtual particles interact with the real ones to replace them? $\endgroup$ Jan 18, 2020 at 4:25
  • $\begingroup$ @NgXinZhao Virtual paraticles are a mathematical instantaneous four vector with the quantum numbers of the particle they are representing, except the mass, they are off mass shell, so it makes no sense to say they replace the real particle, as they are under an integral, while the particle is not. Take a classical example: you throw a ball and its path is a parabola calculated from known physics. Is the parabola the ball? see Feynman diagrams and the virtual defined hyperphysics.phy-astr.gsu.edu/hbase/Particles/expar.html $\endgroup$
    – anna v
    Jan 18, 2020 at 5:16
  • $\begingroup$ @Sofia can you help to see if this particular Feynman diagram is valid? imgur.com/gallery/CrQdLhr Time goes from left to right. An electron is staying still, so from left to right, it's a straight line. A virtual photon got emitted from it, becomes a virtual pair of positron, electron, the virtual position annihilates with the original electron, then the resulting photon got absorbed by the virtual electron, which became real, position of original electron changed. $\endgroup$ Feb 10, 2022 at 9:47
  • $\begingroup$ @NgXinZhao Sofia is not in this thread so will not get your message. $\endgroup$
    – anna v
    Feb 10, 2022 at 11:27
  • $\begingroup$ @NgXinZhao maybe these fourth order contributions to self energy feynman diagrams will help? journals.aps.org/pr/pdf/10.1103/PhysRev.83.1189 d in fig 1 $\endgroup$
    – anna v
    Feb 10, 2022 at 12:17

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