Re: [Phys-l] "filling" the space in an atom

[Roger Haar <haar@physics.arizona.edu>]

Hi,
	Please recall that electrons are not particles in the classical sense 
nor are they waves.  They are totally something else which reveals 
itself as sometimes particle-like and sometimes wave-like. In an atom, 
the other electrons respond as if any given electron is distributed as 
the square of its wave function.  One does not treat electrons as 
point-like "planets" when calculating atomic energy levels or transition 
probabilities.  They are not in one spot.

	In some collision work the electron can briefly be treated as a point. 
 But recall if at one instant you know the position "exactly" then you 
know nothing of it momentum, and thus one will not have an exact 
position the next instant unless you make another measurement.

	I do not see how electrons not being points, means that the mass of the 
universe would be infinite.  The number of electrons would be the same.

Thanks
  Roger Haar
   U of AZ

*****************************************************************************
Richard Tarara wrote:
> > [Original Message]
> > From: Robert Cohen <Robert.Cohen@po-box.esu.edu>
>
> > Subject: Re: [Phys-l] "filling" the space in an atom
> >
> > I think the question is trying to address the misconception that air is
> filling the space between the electrons, protons and neutrons.  How would
> you word the question to identify whether students had this misconception?
> > -----Original Message-----
> > From: phys-l-bounces@carnot.physics.buffalo.edu on behalf of Karim Diff
>
> I think the question is fine.  That the space is filled with fields is
> really not an issue--so is everything we think of as 'empty space.'  The
> electrons don't fill the space either.  We may not know where they are, but
> (a) they are the closest thing we know to a point particle--so they don't
> occupy any space and (b) wherever they are, they can only be at one place
> at one instant in time--otherwise all of space would be simultaneously
> filled with electrons and the mass of the universe would be infinite.  Now
> I recall that Feynman did play around with the idea that there was only one
> electron that could be anyplace AND anytime and thus helped produce all
> matter, but that is equivalent to the idea that each electron is a complete
> universe made up of electrons that also are complete universes--etc.  Fun,
> but pointless.  ;-)
>
> Rick 
>
>
>
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