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

Different speeds of light

  1. Apr 13, 2004 #1
    has anything been written about the idea that light may always be measured as C, becuase that is the only speed at which it is detectable.

    eg, photons go slower - we can't detect them
    photons go faster - we can't detect them

    photons go at c, we can see and detect them.

    in what ways has this idea been dismissed,

  2. jcsd
  3. Apr 13, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    In general, I believe physicists to be very reluctant to assume the existence of unobservables (for example particles which are in principle unobservable/undetectable).
  4. Apr 13, 2004 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Its more of a question of philosophy I believe anyway. Do things exist if we can't detect that they exist? Maybe a more important question is do they matter if we can't detect them? Or it may simply be that we have not discovered the means of detecting a certain phenomena yet, such as when the existance of light beyond both extremes of the visible was first discovered.
  5. Apr 13, 2004 #4
    Do they matter if we can't detect them? Yes, There are more questions than answers in all of sciences. To get answers we need to learn as much as posible and observer all we can. I think that too many people working in sciences dismiss things that they don't understand reather than investigate them.
  6. Apr 13, 2004 #5


    User Avatar
    Science Advisor

    As I understand it, virtual photons are not restricted to speed c. This is important in using quantum electrodynamics to calculate things such as the scattering of an electron off of another electron. If the calculation was restricted to keeping virtual photons at speed c, the result would not match experiment.
  7. Apr 14, 2004 #6


    User Avatar

    Staff: Mentor

    If can't detect them, why do they matter? Any examples of questions an undetectable particle could answer?

    To avoid the inevitable: we're not talking about technology here (ie, we may eventually figure out how to detect it), we're talking about something that by its nature is completely undetectable.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?