Re: [Phys-L] Nme of a surface integral

[John Denker <jsd@av8n.com>]

On 06/20/2012 08:00 PM, Aburr@aol.com wrote:
>  
> In elementary electrostatics what do you  call the two following ys. 
> y = (surface Integral of )D .  dS                      [1]
> andy  =  (surface Integral of )E .  dS                 [2]

They're both called flux.   Reference:  Feynman volume 2 chapter 4
("Electrostatics"), chapter 5 ("Application of Gauss' Law"), 
chapter 18 ("The Maxwell Equations"), and elsewhere.

By the same token we also have magnetic flux, neutron flux, and
lots of other fluxes.

Also, again:  In "elementary electrostatics" the D-field does not
appear.  You can cover all the elementary stuff ... and even some 
not-so-elementary stuff such as the Clausius-Mossotti equation, in 
terms of E.  Reference: volume 2 chapter 11 ("Inside Dielectrics").

If you ever need to distinguish [1] from [2], you should say "flux
of D" or "flux of E".

==========

I am quite aware that in some of the older engineering literature
D is called "the" electric flux density (whereas E is not) ... but 
that is a bad idea.  Don't go there.

As I've said before:  I reckon everybody on this list should reread
Feynman every few years.  There's a lot of good physics in there.
Physics with style, with panache.