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

Planck size and Heisenberg and relativity

  1. Jan 21, 2007 #1
    Is the Planck time/length/mass affected by relativity, or are they constant (independent of relative velocity and/or gravitation field)?

    Same question for the Heisenberg Uncertainty Relation. Is it observer dependent?
  2. jcsd
  3. Jan 21, 2007 #2


    User Avatar
    Science Advisor

    The planck units are absolute in their definition. They have nothing to do with observers or reference frames.

    Heisenberg principle is implicitly in the frame of the observer.
  4. Jan 23, 2007 #3

    Gib Z

    User Avatar
    Homework Helper

    Planck units are constant, thats why the can be used as Natural Units. The Uncertainty Principle describes the uncertainty of certain variables. These variables are measured differently from different observers, so it is dependent.
  5. Jan 25, 2007 #4
    Planck units are a curosity - but they smack of cosmological numerology. Other thought to be constants such as the electron charge can be combined with G and c to lead to different magnitudes for the so called fundamental units. Moreover, if any of the constants picked for the game turn out to be long term variables, the whole notion is lost.
  6. Jan 25, 2007 #5
    Heisenberg's uncertainty in variables (position and momentum and energy and time) shouldn't depend on observer is just a Quantum property in the same sense that Planck Constant or Planck's lenght/time, if relativity predicts the cntrary it should be modified (at least to match quantum scales).
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook