Re: why is S used for displacement

From: george murphy (gmurphy@raex.com)
Date: Tue Jun 25 2002 - 07:29:54 EDT

  • Next message: Sondra Brasile: "Re: Middle East oil supply; alternatives"

    Darryl Maddox wrote:

    > Does anyone on this list know why the symbol s is used for displacement =
    > in physics? If I had to guess I would guess that is to differentiate it =
    > from the concept of distance which is not a vector. But it looks to me =
    > like it would be much less confusing to the students if we used d for =
    > the scaler quantity distance and d for the vector quantity displacement.

             Usually r, in boldface or with an arrow over it, is used for the
    displacement vector while s is often used for its magnitude, though I don't
    know of any compelling reason for either. d isn't so good for either because
    it's a standard symbol for differentiation and something like dd/dt is
    confusing.
             Once you get to discussions of any complexity it's not feasible to try
    to have a different symbol for every quantity. r is a radial coordinate and s
    is also the 4-dimensional interval in relativity (more precisely, ds is the
    infinitesimal interval) as well as specific entropy - & is sometimes used for
    the speed of sound.
             Something that might be a bit easier to track down historically is the
    rationale for the symbols used for fundamental constants. G for the
    gravitational constant is obvious (at least in English) - but why c for the
    speed of light?

    Shalom,

    George

    George L. Murphy
    http://web.raex.com/~gmurphy/
    "The Science-Theology Interface"



    This archive was generated by hypermail 2b29 : Tue Jun 25 2002 - 23:18:14 EDT