Re: EPSILON_ZERO, OK ?

[Jack Uretsky <jlu@HEP.ANL.GOV>]

        F = K*Q1*Q2/r^2  puts electricity, magnetism and gravity on the
same footing.  K is Newton's G for gravity, K_e for electricity, K_m for
magnetism.  The "charge" of gravity is mass, coulomb for electricity, and
coulomb (hidden from view) for magnetism.  The magnetic coulomb may be
like the color charges of QCD, hidden from public view.
        I do not apologize to all who have seen this before.
                                Regards,
                                        Jack

Adam was by constitution and proclivity a scientist; I was the same, and
we loved to call ourselves by that great name...Our first memorable
scientific discovery was the law that water and like fluids run downhill,
not up.
                          Mark Twain, <Extract from Eve's Autobiography>

On Wed, 1 Mar 2000, Daniel L. MacIsaac wrote:

> > Let us invent our own unit of Q and call it S (after Satan). The
> > immediate consequence of this is that the unit of k must be
> > N*m^2/S^2. What is the numeric value of k? It depends on
> > how large is one S. If S is large then k is small, and vice versa.
>
> HA ha ha :^).
>
> > Please verify that the above definition of Coulomb implies that
> > k=8.99*10^9 N*m^2/C^2. It turns out that 4*Pi can be eliminated
> > from some derived formulas if k is written 1/(4*Pi*epsilon_zero),
> > where epsilon_zero is 8.8542*10^-12 C^2/(N*m^2). The name
> > given to epsilon_zero, "permittivity of free space", can not be
> > appreciated in this introductory physics course.
> > Ludwik Kowalski
>
> Ahhh, but you can relate epsilon_zero to something: mu_zero.  You will
> have to explain mu_zero later in your same course.  After that you will
> have to discuss the relationship between mu_zero and epsilon_zero and
> the speed of light c as was (perhaps I am wrong here) discovered by
> Maxwell while playing with the units of epsilon_zero and mu_zero
> and trying to make a constant with units of velocity.  So you have
> a complete and coherent story line for epsilon_zero across three
> chapters.  This puts you ahead of most intro physics texts, which
> have problems maintaining notation (let alone a conceptual story line)
> across chapters.
>
> I'd encourage you to do a little hand-waving on Gauss' law, which ties
> epsilon_zero to k and starts the chain.  And definitely keep the
> Satan system; I'll have to try that myself :^).
>
> Dan, who has no real intention of going to Law School although he
> is often encouraged to develop precision in language in a lawyerly
> fashion.
>
> Dan MacIsaac, Assistant Professor of Physics and Astronomy, Northern AZ Univ
> danmac@nau.edu          http://purcell.phy.nau.edu         PHYS-L list owner