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

Electron annihilation - what happens to gravity

  1. Jun 15, 2012 #1
    It is my understanding (?) that, when an electron is annihilated, the resulting photons do not react with gravity. Why isn't that quality conserved?
     
  2. jcsd
  3. Jun 15, 2012 #2

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Your understanding is incorrect. Where did you read that?
     
  4. Jun 15, 2012 #3

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    Gravitation acts on energy. An electron+positron-annihilation produces photons, which have energy, too.
     
  5. Jun 15, 2012 #4
    I must be misinterpretating the thing about photons not having mass - that electrons interact with gravitons but photons do not.
     
  6. Jun 16, 2012 #5

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    As mfb said, "gravitation acts on energy". The fact that photons have 0 mass does NOT mean they are not affected by gravity.
     
  7. Jun 16, 2012 #6
    The title of the thread stands as an interesting question.

    A particle-antiparticle pair is hald apart by a magic thread. The system has an almost exactly spherical gravitational field.

    At the moment of anhiliation, a pair of photons fly away is opposite directions to preserve momentum, spin, charge and everything else.

    A gravity wave should expand spherically outward from the moment of anhilation to terminate the gravitation from the defunct particles.

    Does this wave contain the binding energy of the particle pair or is it a fraction of their rest masses? Or does it coincide with and somehow represent the outgoing electromagnetic front which is also spherical (even though the two photons will eventually be detected in some colinear trajectory.)

    I think I know the answer but I'd like an expert opinion.
     
  8. Jun 17, 2012 #7
    Is there a quadrupole moment in this case?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Electron annihilation - what happens to gravity
  1. Annihilation operators (Replies: 18)

  2. Detection Annihilation (Replies: 3)

  3. Particle Annihilation (Replies: 4)

Loading...