We start the process with gamma rays collision that produces positron electron pair, the pair then annihilates when hit each other and gamma rays are produced again and everything repeats. Sure, in every step we loose energy but can we keep adding energy to keep this process of constant annihilation/creation? just like we can keep oscillations going?

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    $\begingroup$ Typically pair production happens when a gamma ray interacts with an external electric field (colliding gamma rays is unnecessary). The annihilation of an electron and positron (produced from a single gamma ray) produces two gamma rays; otherwise momentum conservation would be violated. Both of these gamma rays necessarily have lower energy than the original gamma ray. If the energy of a given gamma ray is below the mass of two electrons, pair production cannot happen. How do you propose to "add energy" to this process? $\endgroup$ Commented Aug 7, 2018 at 21:23
  • $\begingroup$ yes, how? hmm maybe by superimpose waves? to reinforce gamma for another collision? $\endgroup$
    – szufla
    Commented Aug 7, 2018 at 22:00
  • $\begingroup$ It's true that superimposing two electromagnetic waves (i.e. large collections of photons) creates a single wave (i.e. large collection of photons) with larger amplitude, but the same does not hold for individual photons. Superimposing two photons does not create one bigger photon. Light doesn't interact with itself at that level like that, especially at gamma-ray energies, where the wavelength of the radiation is so small that the wave picture is basically useless. $\endgroup$ Commented Aug 7, 2018 at 22:05
  • $\begingroup$ You mean that gamma rays (produced by positron electron pair annihilation) energy is low but can be reinforced by superimposing another gamma ray (adding energy to wave) yet the individual photons can't be energized "restored" to the state before annihilation, in other words photons coming from pair annihilation are broken beyond repair so they can't create another electron positron pair? $\endgroup$
    – szufla
    Commented Aug 7, 2018 at 23:10

1 Answer 1


The classical electromagnetic wave is a superposition of zillions of photons in the underlying quantum mechanical framework.

Main stream physics at this time accepts that the underlying level is quantum mechanical. How the classical electromagnetic wave emerges is shown mathematically in this link.

This is the mathematical representation, Feynman diagram, that can be used to calculate the probability of a gamma photon interacting with a field and, given enough energy, generate an electron positron pair.


These two particles cannot meet again to interact as they are going off in different directions.

If the gamma rays impinging on the field have a very high energy , it may be possible that by creating a large number of these pairs, the annihilation gammas can again react with the field and generate more pairs with lower energies. It is a process of diminishing returns, at some point the generated photons from pair annihilation will not have enough energy to give more pairs.

Energy and momentum conservation are absolute laws.

  • $\begingroup$ So we cant add more energy to photons? Ok, "These two particles cannot meet again to interact as they are going off in different directions." We can change their trajectories using magnetic fields to make the pair meet and annihilate. I'm interested in the exact moment of annihilation and production, how could we describe the moment of transition? new state of matter or something? $\endgroup$
    – szufla
    Commented Aug 8, 2018 at 10:15
  • $\begingroup$ All we have are the quantum field theoretical models, and the pair creation as sketched happens under an integral over the values allowed by the experiment. Usually this is the energy momentum space, which can be transformed tp position and time, but it has no meaning to speak of an "instant" as it is an integral over instances. quantum mechanics is a probabilistic theory, only probabilities can be predicted. $\endgroup$
    – anna v
    Commented Aug 8, 2018 at 18:25
  • $\begingroup$ Thank you, this is a stuff for a different question/topic but the idea is to "prolong" the state that exists in between the creation/annihilation of antimatter, and mix this transition state with the observer effect to make a "bubble-field" around some space/matter to isolate it from time space continum.In other words, a new independent (from our universe) frame of reference. $\endgroup$
    – szufla
    Commented Aug 8, 2018 at 21:02

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