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Is this a real graph or is it made up?

  1. Jul 17, 2014 #1
    http://ypelletier.wordans.ca/t-shirt/feynman-gildan-homme-man-81965

    Is this just a cool design or is it a real physics expression (or something that makes sense)?

    I figure it might be something like velocity is converted to work and "e-," and work plus "n" equals pressure, or something...
     
    Last edited: Jul 17, 2014
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  3. Jul 17, 2014 #2

    Nathanael

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    It's a feynman diagram. I don't know about them (except what they look like) but I'm pretty sure that is a real diagram. (Although, I don't know what the physics means.)

    P.S.
    I'm pretty sure the colors are just for the shirt (the colors aren't important to the physics)


    Edit:
    I'm speaking out of ignorance, but:
    I think that feynman diagrams are supposed to represent interactions between particles. Beyond that I do not know any details.
     
  4. Jul 17, 2014 #3

    Drakkith

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  5. Jul 17, 2014 #4

    Nugatory

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    It's a Feynman diagram of a beta decay (a neutron converts to a proton while emitting a neutrino and an electron), rearranged to fit nicely on the T-shirt.
     
  6. Jul 17, 2014 #5

    OmCheeto

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    Too bad they couldn't at least point the arrow in the correct direction.

    http://upload.wikimedia.org/wikipedia/commons/8/89/Beta_Negative_Decay.svg

    Perhaps it's a nerd test.

    "Hey! That should be a positive W-boson. And that should be an anti-electron neutrino. And the arrow implies non-compliance of conservation of charge. Your shirt is not even wrong!"
     
  7. Jul 17, 2014 #6
    Wow, thanks everyone. What a neat diagram.
     
  8. Jul 17, 2014 #7
    Yeah, this makes sense, I think. A neutron separates into two particles, +1 proton and -1 electron. The added neutrino's mass might contribute to the electron's mass. By E=MC^2, the negative work, might contribute to the remaining mass needed for the electron.

    What do you all think?
     
    Last edited: Jul 17, 2014
  9. Jul 17, 2014 #8

    Nugatory

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    Nope. The neutron has greater mass than the proton, the neutrino has negligible mass, and the neutrino is emitted in the reaction (the backwards arrow on the neutrino just indicates that it's an anti-particle instead of a particle). So we start with a neutron, it decays into a lighter proton, the missing mass goes into producing an electron and an anti-neutrino.
     
  10. Jul 18, 2014 #9

    sophiecentaur

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    It's worth noting that the Feynman diagram is purely symbolic. It doesn't show the geometry of a situation, or what an interaction 'looks like'. Many people seem to treat those diagrams as if they actually do.
     
  11. Jul 18, 2014 #10

    CWatters

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