Re: mag. force on wire?

[Leigh Palmer <palmer@SFU.CA>]

At 07:01 -0800 11/3/99, Chuck Britton wrote:
> At 9:33 PM -0800 11/2/99, Leon Leonardo wrote:
> > Another question: HOw can the Hall effect distinguish
> > hole-flow (P's) from 'N's in a semi-conductor when in
> > either it is electrons that are actually flowing?
>               ^^^^^^^^^          ^^^^^^^^
>
> You mustn't 'reify' the electrons. 'Holes' are just as 'real'. (at
> least in a solid)

Right on, Chuck! I might add to this important observation that
the fact that electrons are indistinguishable from one another
ought to reinforce their abstract nature. The "fact" that in
solids electrons usually have different masses than they have
in free space should also give one a clue.

An abstract idea can be very useful. One must remember always
that utility does not confer reality. Diffraction of electrons
becomes quite upsetting if one becomes too comfortable with the
concrete electron.

Leigh