Re: Physics Definition of Work -- Quis custodiet ipsos custodes?

[kowalskil <kowalskil@MAIL.MONTCLAIR.EDU>]

"John S. Denker" wrote:

> 1) There are many situations where sign conventions are well
> established.  For instance, electrical engineers take the sign
> of the electron to be negative, just to be compatible with
> physics and with long-standing tradition -- even though the
> opposite sign would be more convenient.

YES, I WOULD SUPPORT A CONVENTION IN WHICH ELECTRONS ARE
POSITIVE, PROTONS ARE NEGATIVE, ETC.. IT WOULD BE MUCH
EASIER TO IMPLEMENT THAN CHANGING THE CONVENTION ABOUT
THE ELECTRIC CURRENT. THE SITUATION WE NOW HAVE IS NOT
DESIRABLE, FROM THE PEDAGOGICAL STANDPOINT.

> 4) There is no standard definition of "physics work" and probably
>    never will be.  There are in fact two competing notions:
>   -- work done _by_ the system
>   -- work done _on_ the system
> and the over-abbreviated phrase "physics work" is just guaranteed
> to be ambiguous.

On the other hand we do have a standard definition of "work
done by a force' or "work done by the net force". It a dot
product of F and dX; I am never confused about the sign.

I am aware of the dilemma "Work done on a piston (by a gas) or
work done by the piston (on the gas)? If one is positive then
the other must be negative. But which one?" I WOULD SUPPORT
ANY CONVENTION DESIGNED TO ELIMINATE PRESENTLY EXISTING AMBIGUITY.
Who should we ask for changes of conventions (for the sake of
pedagogical and practical convenience)?
Ludwik Kowalski