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

Energy and Mass

  1. Nov 18, 2014 #1
    I am just very curious if anybody could help me figure out which dimensions
    actually entail energy and matter axis. Also since colors are absorbed are there residual colour energies if so is there a known half-life? Any feedback would be greatly appreciated, thank you.
  2. jcsd
  3. Nov 18, 2014 #2


    User Avatar
    Science Advisor
    Gold Member

    The only way it makes sense to talk about dimensions of energy and matter is in the context of dimensional analysis. That is, basically what units are the two expressed in. Mass is then its own fundamental dimension and is expressed in kg, while energy is expressed in Joules and in terms of fundamental dimensions it is m*kg*m/s^2.

    If you were thinking more about dimensions like those of space and time, then they have none, as they are scalars(have only magnitude, no direction).

    As for colours, I'm not sure what you meant by "colours are absorbed". The perception of colours is the result of parts of the visible spectrum being absorbed by the material on which white light shines, or the source emitting light of different than solar spectrum(e.g., only blue, or less red). In the narrower physical sense, a given colour is just a shorthand for a range of wavelengths of the electromagnetic radiation in the visible region.
    Absorption is the result of chemicals in the material having vibrational frequencies matching those of a given light frequency, which allows the incoming photons to be converted into more vibration(heat up the material), rather than just being reflected.
    There are no "residual colour energies" in current physics (which is all we can talk about on this forum), and it makes no sense to talk about half-life in this context.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook