1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Proper Length and Photons

  1. Jun 5, 2005 #1
    Hi all,

    If I have a length [itex]L_p[/itex] of an object which is at rest in my frame of reference, it will have length [itex]L = L_p (1 - \frac {V^2}{c^2})[/itex] in an inertial reference frame moving with speed [itex]V[/itex] relative to me. If this frame is following a photon at speed [itex]c[/itex], that makes [itex]L = 0[/itex].

    If my object is the universe, it seems like my photon thinks it is everywhere at the same time, because the distance to anywhere in its IFR is zero. How does that work?

  2. jcsd
  3. Jun 6, 2005 #2

    Meir Achuz

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    You cannot make a LT to the rest frame of a photon.
    A photon does not have a rest frame.
    You have given some reasons why.
  4. Jun 6, 2005 #3

    James R

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    "LT" = "Lorentz transformation", by the way.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Proper Length and Photons
  1. Proper length (Replies: 9)

  2. Spacetime/Proper Length (Replies: 14)