What is the role of photon-photon collisions in the creation of the universe?

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Discussion Overview

The discussion centers on the role of photon-photon collisions in the context of the creation of the universe, exploring both theoretical implications and experimental observations related to photon interactions in quantum physics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant inquires about the physics of photon collisions and their potential effects in quantum experiments.
  • Another suggests that photon collisions may lead to interference patterns, indicating a wave phenomenon, but expresses uncertainty about the quantum implications.
  • A participant clarifies that photons do not interact directly with each other but can scatter indirectly through virtual particles, noting that such processes have been studied but not observed due to small cross-sections.
  • One participant asserts that photon-photon collisions were common right after the Big Bang, leading to various particle-antiparticle pairs.
  • Another participant requests specific references from Wikipedia regarding photon-photon collisions.
  • A later reply points to Delbrück scattering as related to photon-photon scattering processes.
  • A participant elaborates on the early universe's conditions, discussing the high energy density and the creation of particle-antiparticle pairs, suggesting that photon-photon collisions contributed to the creation process.

Areas of Agreement / Disagreement

Participants express differing views on the nature and implications of photon-photon collisions, with some asserting their significance in the early universe while others emphasize the lack of direct interactions between photons. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

There are limitations regarding the assumptions made about photon interactions and the speculative nature of early universe conditions. The discussion includes references to complex processes that are not universally agreed upon.

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Photon collision physics?

Can anybody explain the physics behind the collision of two photons if they do collide, also what are the phenomenon which arise due to this collision, do such collisions have any impact in experiments in quantum physics involving photons!
 
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hi...
Though i am not sure , but reading your question it occurred to me as if you are talking about two photons hitting each other...May be to interfere (create an interference pattern), though this is a wave phenomenon as per classical physics. But quantum should be able to digest this...
I am looking forward to an answer to your question, because it is definitely interesting.
 


Photons interact directly only with objects that are charged, so there is no direct interaction between two photons. Photon-photon scattering in principle can occur indirectly through the creation of virtual particles such as electron-positron pairs. See this diagram. Such processes have been studied but never observed experimentally since the cross-section is very small.
 


Could you please quote the part in this Wikipedia page where photon-photon collisions are mentioned.
 


Bill_K said:
Could you please quote the part in this Wikipedia page where photon-photon collisions are mentioned.

The earliest phases of the Big Bang are subject to much speculation. In the most common models the Universe was filled homogeneously and isotropically with an incredibly high energy density and huge temperatures and pressures and was very rapidly expanding and cooling. Approximately 10−37 seconds into the expansion, a phase transition caused a cosmic inflation, during which the Universe grew exponentially.[18] After inflation stopped, the Universe consisted of a quark–gluon plasma, as well as all other elementary particles.[19] Temperatures were so high that the random motions of particles were at relativistic speeds, and particle–antiparticle pairs of all kinds were being continuously created and destroyed in collisions. At some point an unknown reaction called baryogenesis violated the conservation of baryon number, leading to a very small excess of quarks and leptons over antiquarks and antileptons—of the order of one part in 30 million. This resulted in the predominance of matter over antimatter in the present Universe.[20]

My underline. Creation resulted from photon-photon collisions.
 

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