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

Absolute or relative TIME

  1. Aug 21, 2009 #1
    According to Special Theory of Relativity nothing is absolute in this universe, but relative to each other. as we know that Einstein told me that speed of light is max. Now i'm little bit confuse if speed of light is absolute or relative i.e it may be max. for initial reference frame but for any other frame it may/should be change from the value of 3 X 108 m/s. can anyone give me the reason for this.
  2. jcsd
  3. Aug 21, 2009 #2


    Staff: Mentor

    That is not correct at all. There are many things which are absolute in SR. E.g. the spacetime interval, proper time, mass, the norm of the 4-acceleration, etc.
  4. Aug 21, 2009 #3


    User Avatar

    Staff: Mentor

    And it is probably more correct to say that the speed of light is a constant, not an "absolute" or a relative thing. Ie, it is a constant relative to any inertial observer.
  5. Aug 21, 2009 #4

    George Jones

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Actually the locally measured speed of light is constant relative to any observer, inertial or not, in both special and general relativity.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Absolute relative Date
I Energy of Relativistic Particles Jan 21, 2018
B Relative rotation Oct 10, 2017
I Absolute Energy in General Relativity? Jan 26, 2017
I Relative velocity time dilation Aug 5, 2016
B How can we tell that "fictitious forces" are not real? Apr 25, 2016