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

Energie lost of the universe

  1. Jun 16, 2004 #1
    I am wonderring is there a known solution to the problem that all the light emitted by the stars must come out of the univers (if it is finite). All the energie is then lost and if the univers loses energie, it loses mass hence is bound to disappear someday... *if there will be an end, there was a begining*

    In other words is the univers subject to the laws of conservation of energie, mass and even momentum? Is there a shape or any property of the univers that eliminates this problem of energie loss?
  2. jcsd
  3. Jun 17, 2004 #2
    Why do you say the energy 'was lost' when light is emitted by the stars - it isn't, it just travels through the Universe as Photons of light.

    Energy is conserved in the Universe as a whole, yes. Don't forget, Energy and mass can be seen as the same thing (E=mc^2), and changing mass to energy does not therefore break conservation laws.

    The latest evidence for the future of the Universe is continual expansion for infinite time.
  4. Jun 17, 2004 #3


    User Avatar
    Science Advisor

    I think the biggest problem with your question is in understanding the concept that the light does not have to leave the universe just because the universe is finite. If the universe is finite, its boundaries are defined by how far its farthest component has traveled, and this includes the photons emitted by Stars.
  5. Jun 17, 2004 #4


    User Avatar
    Science Advisor

    It is quite possible for the universe to be finite and still have no boundaries in the same way the surface of a sphere is finite but has no boundaries.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook