Re: Kraft

["Donald E. Simanek" <dsimanek@eagle.lhup.edu>]

On Mon, 3 Mar 1997, Igal Galili wrote:

> > > Can someone please give the transliteration of the german word
> > >
> > > Kraft
> > >
> > > together with some possible connotations.
>
> > M.A. Santos
>
>         My dictionary also mentions "power", as a second synonym, and
> "energy", as  a meaning  for "Kraft" in physics (!).  It is natural to have
> such a mixture of meanings in language though it is totally unacceptable
> today in physics.  But look at the free use of these notions by Galileo.
> And I would, of course, ask our colleague Hans Niedderer
> (niedderer@physik.uni-bremen.de)  from the University of Bremen.
>
> Igal.

The word "kraft" was commonly used in the 18th century, and is seen in the
papers (and titles) of works on thermodynamics by Clausius and others.
Bear in mind that Carnot's papers were written with the implicit
assumption of a substance of heat (caloric), and that in works by Joule
the words for power, force, energy and momentum seemed to be casually
interchangeable. 

Totally unacceptable today, you say? Ha! I hear physics teachers
frequently speaking of "electromotive force" which isn't a force, talking
about "flow of current" (current *is* a flow of charge), and refering to
"voltage, amperage and wattage" instead of "potential, current and power". 
Many of these are historic relics. While they will say "mileage", they
will never say "kilometerage", and they speak of "percentage" when
"percent" would do just fine.  They talk of ratios of unlike things as in
"the ratio of charge to mass of the electron" (should be "specific charge
of the electron"). Consistent? Logical? Hardly. 

	-- Donald