Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Chicken or the Egg

  1. Feb 24, 2011 #21
    Then perhaps you can tell me what the radii are for quarks and electrons?

    QFT may not predict that electrons and quarks are point particles, but, as far as I am aware it doesn't predict that they are not point particles either, and physics has no size for either of these.
     
  2. Feb 25, 2011 #22
    Nice quote. One I appreciate. However, I would say that Russell was philosophizing, but doing a better job of it. Do you happen to know what publication was this from?
     
  3. Feb 25, 2011 #23
    Sorry, I can't recall where I first came across it - I just googled it.
     
  4. Feb 25, 2011 #24
    How can people state that virtual particles are not real? Of course they are real. They have calculatable effects on the energy levels of atoms. It is a small energy, but such an energy has been measured. How can you measure something that is not real?
     
  5. Feb 25, 2011 #25
    I'd say particles came from virtual particles. It is the only logical order, as it is with Chicken producing an egg.

    Before any real matter was about, the vacuum was teeming with virtual particles. They live inside the vacuum, and is what makes up zero-point energy or even a Dirac sea if one can picture it.
     
  6. Feb 25, 2011 #26
    It strikes me that elementary particles such as electrons and quarks have no real existence of their own. They are essentially defined by their field effects, which are mediated by virtual particles.

    No one has ever observed either, they have no descernible size, their existence is inferred from observed macroscopic effects. The same can be said of virtual particles of course, but, with both being mathematical models to help explain observable phenomena, I would suggest that virtual particles have primacy and it would be more sensible to look for a description of electrons and quarks in terms of virtual particles popping into and out of existence, than describe virtual particles in terms of what electrons and quarks are doing. Bottom up rather than top down.
     
  7. Feb 25, 2011 #27

    A. Neumaier

    User Avatar
    Science Advisor

    Only people informed primarily by lay men's literature claim that. See Chapter A7 of my theoretical physics FAQ at http://www.mat.univie.ac.at/~neum/physfaq/physics-faq.html#A7 and the PF thread https://www.physicsforums.com/showthread.php?t=460685
    The Casimir energy has been measured, not a virtual particle.
     
  8. Feb 25, 2011 #28

    A. Neumaier

    User Avatar
    Science Advisor

    See the entry ''Are electrons pointlike/structureless?'' of Chapter B2 of my theoretical physics FAQ at http://www.mat.univie.ac.at/~neum/physfaq/physics-faq.html#pointlike
     
  9. Feb 25, 2011 #29
    Well, aren't we just being a little pedantic however?

    The Casimir Force, or more specifically the Lamb shift is caused by virtual particle energies. The Casimir force is in fact nothing more than an increasingly negative energy density between two plates in a vacuum via the interaction of virtual particles.

    So I am interested how you can say what you say?
     
  10. Feb 25, 2011 #30

    A. Neumaier

    User Avatar
    Science Advisor

    Didn't you complain about others being patronizing? Practice yourself what you preach!
    No. http://lanl.arxiv.org/abs/hep-th/0503158 derives and calculates the Casimir effect without the use of virtual particles. Thus the latter cannot be their cause.
    I gave references for that. If you really are interested, read them!
     
  11. Feb 25, 2011 #31

    DarMM

    User Avatar
    Science Advisor

    You can derive the Casmir force nonperturbatively, in fact I think it's done in introductory textbooks like "Quantum Field Theory in a nutshell" by A. Zee. In such a derivation there are no "virtual particles".
     
  12. Feb 25, 2011 #32

    Demystifier

    User Avatar
    Science Advisor
    2018 Award

    That's true. In fact, I have never seen a derivation of the Casimir effect with virtual particles. The issue is not whether Casimir effect proves the reality of virtual particles (which it certainly doesn't), but whether it proves the reality of the zero-point energy (which is controversial, especially after the Jaffe's paper). Contrary to a frequent misconception, zero-point energy has absolutely nothing to do with virtual particles.
     
  13. Feb 25, 2011 #33
    For the last few posts, especially A. Neumaier's response, this is all down to interpretation.

    Quantum mechanics directly predicted the existence of virtual particles long before any other explanations where concocted - and really were only created because certain scientists did not fully appreciate this existence which seems to have been for all practical terms, has been proven experimentally. Inviting new interpretations because people do not like the idea of virtual particles seems superfluous and redundant.
     
  14. Feb 25, 2011 #34
  15. Feb 25, 2011 #35
    You sure???

    I'd agree that zero point energy ISN'T virtual particles and doesn't derive from virtual particles or what they are doing, but I wouldn't say it has nothing to do with them. More like the virtual particles are "anomalies" within the zero point energy field.
     
  16. Feb 25, 2011 #36
    except that this guy has recorded it.....

    http://www.geo600.org/documents/audio-files [Broken]

    http://arxiv.org/PS_cache/arxiv/pdf/0709/0709.0611v1.pdf

    http://en.wikipedia.org/wiki/GEO_600

    http://www.fnal.gov/directorate/program_planning/Nov2009PACPublic/holometer-proposal-2009.pdf

    http://holometer.fnal.gov/
     
    Last edited by a moderator: May 5, 2017
  17. Feb 25, 2011 #37
    This is partially right. Zero point energy actually has a lot to do with our understanding of virtual particles when viewed as a vacuum which spontaneously bubbles energy at very small quantum levels. you try and remove all the energy from a part of space by cooling it down, you will never reach zero temperatures. What is left is an intrinsic energy which may as well be seen in terms of a virtual particle couldron boiling from the vacuum.
     
  18. Feb 26, 2011 #38

    A. Neumaier

    User Avatar
    Science Advisor

    According to the mainstream view, yes. Whereas virtual particles and imaginary electrons don't.
     
  19. Feb 28, 2011 #39
    consensus reality - have you ever seen an electron, I know I haven't. It seems that scientists are just as capable of believing in their invisible imaginary friends as deists are, lol.

    I've found reference to research on 'wet electrons' that claim to have isolated electrons in a sort of limbo state, but still no piccie.

    For something to exist - in any meaningful sense - it ought to at least have a shape and definable size.

    Now that doesn't dismiss the usefulness and validity of the concept of an electron within physics and its function in the world, but, by the same token, the usefulness and validity of virtual particles would be no less valid. If it works, use it.

    Re: size of an electron.
    This looked promising until I realiseed who the author was.............lol.
    http://prola.aps.org/abstract/PR/v14/i1/p20_1
     
  20. Feb 28, 2011 #40
    Which is the size and shape of the wind? And of a collection of sea waves? So they don't exist?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook