Calculating Particle-Antiparticle Rates in Vacuum Space w/ QT

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Discussion Overview

The discussion centers on the rate of formation of particle-antiparticle pairs in vacuum space according to Quantum Theory, specifically focusing on calculations for various particles such as electrons, positrons, photons, and gravitons. The conversation explores the implications of virtual particles and their role in these processes.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about the specific rates of formation of particle-antiparticle pairs in vacuum space, seeking numerical values for different particles.
  • Another participant suggests that the concept of virtual particles may be an artifact of the perturbation formalism in Quantum Field Theory (QFT), complicating the calculation of these rates.
  • Concerns are raised about the existence of virtual particles, with references to Hawking Radiation and the Casimir Effect as phenomena that may challenge this view.
  • It is mentioned that there are methods to calculate phenomena like Hawking Radiation and the Casimir Effect without invoking virtual particles, although these methods are less developed and understood.
  • A participant expresses gratitude for the clarification regarding virtual particles and suggests ending the discussion, indicating a desire to explore further questions in new threads.

Areas of Agreement / Disagreement

Participants express differing views on the existence and relevance of virtual particles, with some arguing they do not exist while others question how certain phenomena can be explained without them. The discussion remains unresolved regarding the implications of these differing perspectives.

Contextual Notes

The conversation reflects limitations in understanding the role of virtual particles and the complexities involved in calculating particle-antiparticle formation rates in vacuum space. There is an acknowledgment of the infancy of non-perturbative methods in this context.

Jim Hasty
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I am interested specifically in the rate of formation of particle-antiparticle pairs in the empty void of vacuum space according to Quantum Theory? For example: for any given cubic centimeter of empty vacuum space, the rate of formation of electron-positrons is X pairs per second; the rate of formation of photons, or gravitons, is Y and Z pairs per second, and so on. The term "RATE" would include a complete cycle such as the creation-pairing-annihilation. How would these numbers be calculated according to QT?
 
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Jim Hasty said:
I am interested specifically in the rate of formation of particle-antiparticle pairs in the empty void of vacuum space according to Quantum Theory?

The issue is complicated by the fact its now thought virtual particles are simply an artefact of the perturbation formalism used in QFT - they don't really exist.

Its a bit hard to calculate what you are asking for things that are mathematical artefacts.

Thanks
Bill
 
bhobba said:
The issue is complicated by the fact its now thought virtual particles are simply an artefact of the perturbation formalism used in QFT - they don't really exist.

Its a bit hard to calculate what you are asking for things that are mathematical artefacts.

Thanks
Bill
 
If they do not exist - then what explains Hawking Radiation or the Casamir Effect ?
 
Jim Hasty said:
If they do not exist - then what explains Hawking Radiation or the Casamir Effect ?

We don't know at this stage because non-perturbative methods are still in their infancy. We simply know when they are not used virtual particles do not appear.

Check out:
http://arnold-neumaier.at/physfaq/topics/virtual

'The collection of Feynman diagrams without loops describes exactly the scattering of classical fields in a perturbation theoretic treatment; the diagrams with k loops describe quantum corrections of order O(hbar^k). If virtual particles had a meaning, then they would already exist in classical field theory, since tree diagrams have internal lines. But nobody ever claimed that predictions of classical field theories bare caused by virtual particles.'

Thanks
Bill
 
Jim Hasty said:
If they do not exist - then what explains Hawking Radiation or the Casamir Effect ?

As I understand it, there are ways of calculating both of these that do not involve virtual particles.
 
jtbell said:
As I understand it, there are ways of calculating both of these that do not involve virtual particles.

That's correct.

Its just they are not as advanced as the pertubative methods and not understood as well since they are done on computer.

Thanks
Bill
 
OK. Thank you for enlightening me about "virtual particles" - they don't exist. I would like to propose we end this discussion. I do have more questions that I will pose in some new threads. Thanks to all. Special thanks to Bhobba for the VP reference.
 

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