Re: Current is a vector

From: César Sirvent (8umucsxySPA_at_M_MAPSterraReMoVeThIs.es)
Date: 06/03/04 

Date: Thu, 03 Jun 2004 19:21:00 GMT

"shuba" <tim.shuba@eudoramail.com> escribió en el mensaje
news:tim.shuba-C83A53.14041403062004@cp-news.centix.net...
> César Sirvent wrote:
>
> > Not admiting that he could be wrong at least once in his life?
>
> I did. I don't have Griffiths' text. So the mistake still made
> its way into the third edition. Big deal. As a said, there are
> many mistakes even in good books. Ensle, apparently unaware of
> that fact, would rather purposefully pertetuate an error than
> learn about the subject. Nothing new there, as he has been
> spreading misinformation about relativity for years. Ensle
> likely doesn't need an errata list for his own vanity press book,
> since the entire thing almost certainly qualifies as errata.
>
> It's easy to verify that current is not a vector. I gave a link
> to NIST, which has the official definition of current. Or one
> can look at myriad of texts and presentations that don't make the
> mistake of referring to a current density as a current. It's
> Ensle in fact that is refusing to admit that he is wrong.
>
>
> ---Tim Shuba---

In fact, all depends on what you define as current. In every textbook I have
seen, it is defined as a scalar, and later the (volumetric) densiy of
current is introduced, which is a vector. Even for some of the derivations
that need to know the direction of the current, it is used I * ds, with ds
being the infinitesimal element of line.

Whether you re-define vectorial I as I * ds is just a convention, and I
would not consider it an error. In any case, I have always seen I as a
scalar, and the only doubt I had was dissipated by checking the source,
Wangsness' textbook.

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