Gamma radiation speed

Discussion in 'Physics & Math' started by Xelios, Oct 6, 2002.

  1. Xelios We're setting you adrift idiot Registered Senior Member

    Messages:
    2,447
    I was sitting through another boring gr. 12 Chem class when my teacher said something that interested me. He said that gamma radiation travels at the speed of light, or higher. Now, since gamma radiation is made up of matter particles, how can it travel faster than c?
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Crisp Gone 4ever Registered Senior Member

    Messages:
    1,339
    Hi Xelios,

    I think your teacher was wrong. Gamma radiation is plain high-energetic photon radiation, and hence it travels at the speed of light (in the medium it is travelling through).

    Bye!

    Crisp
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Prosoothus Registered Senior Member

    Messages:
    1,973
    Xelios,

    Crisp is right, gamma radiation can't travel faster than c. But it can travel faster than the speed of light of the medium that it is travelling through.

    Tom
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. c'est moi all is energy and entropy Registered Senior Member

    Messages:
    583
  8. (Q) Encephaloid Martini Valued Senior Member

    Messages:
    20,834
    Prosoothus and Cest Moi

    I'm not sure whether to label you guys, " Rebels without a Cause," or "Rebels without a Clue."

    Please Register or Log in to view the hidden image!



    I'm almost positive if I were to ask you what it is about science you feel the need to rebel against, you're answer would be:

    "Whadda ya got?"

    Please Register or Log in to view the hidden image!

     
  9. Prosoothus Registered Senior Member

    Messages:
    1,973
    Q,

    Don't you call yourself "The Dissident"??? Maybe you should change it to "The Conformist".

    Please Register or Log in to view the hidden image!



    Tom
     
  10. Crisp Gone 4ever Registered Senior Member

    Messages:
    1,339
    Hi Tom,

    " But it can travel faster than the speed of light of the medium that it is travelling through."

    Ehrrrrr.... I think not. Gamma radiation *is* light, and hence bound by all the restrictions that come with being light. One of those is that it travels at the speed of light (even in the medium it is travelling through). Other radioactive radiations (that are particle based, such as alpha or beta radiation) can travel faster, leading to all kinds of exotic effects like Cherenkov radiation

    Please Register or Log in to view the hidden image!

    .

    Bye!

    Crisp
     
  11. Prosoothus Registered Senior Member

    Messages:
    1,973
    Crisp,

    Your right, and I'm wrong.

    I thought that Cerenkov Radiation can be caused by gamma rays.

    Tom
     
  12. c'est moi all is energy and entropy Registered Senior Member

    Messages:
    583
    doesn't this contradict relativity? has this speed been measured?
     
  13. chroot Crackpot killer Registered Senior Member

    Messages:
    2,350
    No.
    Of course.

    - Warren
     
  14. Xelios We're setting you adrift idiot Registered Senior Member

    Messages:
    2,447
    Thought so =)
     
  15. c'est moi all is energy and entropy Registered Senior Member

    Messages:
    583
    chroot, it seems to these days on this board, no explanation is needed any longer. oh well..
     
  16. thed IT Gopher Registered Senior Member

    Messages:
    1,105
    It was predicted within the realms of known physics by a chap called Cerenkov. As you well know the speed of light is slower in mediums other than a vacuum. Photons emitted by nuclear fission processes are emitted at the speed of light in vacuo. Being as the material sits in a water bath, having a lower speed of light than in vacuo, the particles HAVE to slow down. Which they do by giving energy off. That is what we see as Cerenkov radiation.

    has this speed been measured?

    If you mean, has some gone into the reaction chamber with a pencil and ruler and actually measured a single photon given off by a radioactive nucleus, no. If you mean, does the spectrum of the radiation exactly match, within error bars, the prediction of the model used by Cerenkov based on models of nuclear decay, the energies involved and how light/photons interacts with a medium as per accepted physics. Then yes, it has been measured.

    I've had the fortune of actually seeing Cerenkov radiation. A truly awesome sight.
     
    Last edited: Oct 7, 2002
  17. c'est moi all is energy and entropy Registered Senior Member

    Messages:
    583
    Ah Thed,

    don't understand this piece
    Crisp said that the radiation travels faster than Gamma radiation. Does he and you mean, that when ordinary gamma radiation travels through some medium, going slower than its speed in vacuum, that the radioactive radiation DOES reach the speed of light (in vacuum) regardless of that medium?
     
  18. thed IT Gopher Registered Senior Member

    Messages:
    1,105
    C'est moi

    Have a read of this, http://nova.nuc.umr.edu/~ans/cerenkov.html

    It's a better description than I gave. My description was badly worded, that'll teach me to speed type when management are watching over my shoulder.

    ------------------------------------------------------------------------

    Edit to add, the description I gave was just plain wrong. The daft thing is some one asked the same question on uplink.space.com this morning and I gave them the correct explanation. Wierd.

    --------------------------------------------------------------------------
     
    Last edited: Oct 7, 2002
  19. c'est moi all is energy and entropy Registered Senior Member

    Messages:
    583
    Thed, I missed you too

    Please Register or Log in to view the hidden image!

    Think I'd like to have some talk with you with a nice lager. should be nice
     
  20. Emfuser Registered Senior Member

    Messages:
    90
    Well yes, in a way. Cerenkov radiation occurs when electrons exceed the local speed of light. Those electrons can be accelerated to that speed by gammas.
     

Share This Page