1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

A If light transmitting without media, then

  1. Sep 6, 2015 #1
    then where light transmits to in the universe? Does that mean the universe expanding speed is at least light-speed? Because we know light is energy, it is part of our universe. As if it is like this, the universe expands endless and will become cold and dark.

    It sounds impossible to me
  2. jcsd
  3. Sep 6, 2015 #2
    Turn on a lamp. Notice the room gets brighter. That has nothing to do with the expansion of the universe. Light does not require a medium---that's just a fact of physics.
  4. Sep 6, 2015 #3


    User Avatar

    Staff: Mentor

    Asked, answered, locked.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook