Classical physics vs quantum physics

  1. Why do we say that classical physics is a lot different from quantum physics?

    The laws that determine the macroscopic world should be derivable from quantum laws. So in a way the Newtonian or classical laws are basically quantum laws( maybe a bit approximated)
    So why differentiate between macroscopic and microscopic world?
  2. jcsd
  3. Simon Bridge

    Simon Bridge 15,471
    Science Advisor
    Homework Helper
    Gold Member

    We don't (except by mistake). We say that quantum physics is different from classical physics :)

    All dogs may be animals but not all animals are dogs.
    All classical physics is a consequence of quantum - but not all quantum physics can be described classically.

    Technically - classical physics is what QM does on average ... so the math is different.
Know someone interested in this topic? Share this thead via email, Google+, Twitter, or Facebook

Have something to add?