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

Help with vacuums and particles

  1. Dec 10, 2005 #1
    Can ya'll help me with this one:


    Vacuums (in space) are regions of space absent of [this is where I am uncertain] elements(?) but which contain subatomic particles like leptons, baryons, etc(?){how can this be right?} as well as photons and anti-photons(?).


    Please help clarify what exists in a vacuum and what doesn't. I know that photons and anti-photons must exist because light can travel through a vacuum, but beyond that, I am lost.

  2. jcsd
  3. Dec 10, 2005 #2
    Ok, we have debated this many times here and i suggest you do a search for "vacuum fluctuations" on this forum or consult my journal or the "elementary particles presented" thread.

    Meanwhile i suggest you look at following NASA-site and scroll down to the text on http://www.nasa.gov/centers/glenn/research/warp/possible.html#vac [Broken]. It gives a good introduction on what is going on. feel free to ask more questions if something is not clear



    ps : there is no anti-photon, a photon is its own anti-particle. QM is strange, isn't it :)
    Last edited by a moderator: May 2, 2017
  4. Dec 10, 2005 #3
    ...tangent question while reading bout vacuums...

    Are these unrelated statements correct?

    Leptons and neutrinos both exert gravitational force.

    Photons do not exert gravitational force.

    Photons cannot become neutrinos, leptons, baryons, or fermions.

  5. Dec 11, 2005 #4
    YES they do

    yes they do exert gravitational force. energy is mass remember ?

    photons when coupled to the appropriate massive object (to obey to momentum conservation) will be able to take part in interactions (weak interaction, hadronization, excitations,...) that emit hadrons and leptons. Fermions are particles with odd spin that can either be a member of the hadron (quarks, neutron,...) or the lepton (eg electron) family. Neutrino's are member of the lepton family.

    Last edited: Dec 11, 2005
  6. Dec 12, 2005 #5

    So would this statement be correct then:


    A photon has all its energy in the form of light and none in mass. However, photons may take part in interactions (as mentioned above) which may result in a larger particle, which must have some of its energy in the form of mass.


    Beyond that, what branch of science is looking into how these "fundamental particles" were created, or came to be?
  7. Dec 12, 2005 #6
    A photon indeed has no restmass and for that reason, it always moves at the speed of light.

    Photons indeed take part into interactions between MATTER particles.

    high energy physics, Quantum Field Theory (ie the theoretical formalism). Look at the "elementary particles presented" thread here

    err dare i say string theory ???

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook