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Dramatic Difference In Matter Vs. Antimatter

Posted by michael on from the things-that-go-bang dept.

jma34 writes "The Stanford Linear Accelerator Center (SLAC) recently put up a press release announcing a 13% asymmetry between the interactions of matter and anti-matter. In most interactions matter and antimatter are mostly interchangeable, however our universe is matter dominated. This research helps to answer the question of where did all the antimatter go. PRL article here."

3 of 45 comments (clear)

  1. Re:why not? by Anonymous Coward · · Score: 5, Informative

    photons are their own antiparticles in the standard model.

  2. Re:why not? by jerde · · Score: 5, Informative

    Because once the antiphotons hit our eyes we'd all annihilate

    No such thing. Or, at least, the photon is its own anti-particle, as far as I can find. I am not a particle physicist, nor do I play one on TV, but my limited understanding is that matter is a type of "frozen" energy with certain charge and spin, and anti-matter is the same phenomenon but with opposite charge and spin.

    Photons are just energy, with no properties you can put backwards as in anti-matter. I did find a number of pages out there that talk about anti-photons as somehow photons moving backwards in time, but I can't quite wrap my mind around that one.

    Anti-matter would "look" the same as matter from a distance, I think. The glow of an anti-matter star would be pretty and warm, until you got close enough for the anti-matter solar wind to start annihilating you.

    - Peter

    --
    INsigNIFICANT
  3. Re:We can also conclude . . . by rangek · · Score: 4, Informative

    since the area around the Sand Hill Road exit on I-280 in Menlo Park still exists, SLAC has *not* yet succeeded in bringing matter and amtimatter together.

    Huh? SLAC's whole purpose in life is to fire electrons and positrons at each other. The resulting collisions create the deacys they study. Why would this make "the area around the Sand Hill Road exit on I-280 in Menlo Park" no longer exist?

    If all of the energy of one positron and one electron were released in a collsion in the SLAC, something like 3 billionths of a Joule. Well, there could be a lot of particles... Hrm... digging around http://www.slac.stanford.edu/ and crunching their numbers... I get a total output on the order of 3000 kJ/s if all of their particles collide with each other. Gasoline has a heat of combustion of about 43MJ/kg, so that is the same amount as burning 7 thousandths of a kilo of gas per second.

    I think Menlo Park and the surrounding are are quite safe.