Re: [Phys-l] BEC

[Ludwik Kowalski <kowalskil@mail.montclair.edu>]

It is not my cup of tee but I have a comment. You are saying that atoms 
are bosons, not naked nuclei. Consider a molecule, in which electrons 
are said to be "shared" between atoms. Which electrons should be 
counted? If atoms are treated as single bosons then why not molecules? 
And if molecules then why not groups of molecules, for example a 
nonocrystal, or a much larger object?

On May 16, 2006, at 11:59 PM, Aloysius Rusli wrote:

> Thank you. I  will look into this again; but all these isotopes have 
> odd
> numbers of nucleons, so it looks difficult to get integer spins for
> them. The other answer from New Zealand counts in the electrons, and
> that will do the job. . . .
>
> Sincerely,        A Rusli        17 May 2006
>
> Jack Uretsky wrote:
>
> > Hi Aloysius-
> > 	The criterion is the nuclear spin.  Bosons have integer spin,
> > fermions have half-odd-integer spin.  The isotopes you named all have
> > integer spin.
> > 		Regards,
> > 				Jack
> >
> > On Tue, 16 May 2006, Aloysius Rusli wrote:
> >
> > > Dear friends,                    16 May 2006
> > >
> > > I would like to ask on the recent discoveries of Bose-Einstein
> > > Condensates : It is reported that Rb-85, Rb-87, NA-23, Li-7, are 
> > > bosons,
> > > while to my understanding they contain odd numbers of protons and/or
> > > neutrons, which should cause them to be fermions instead.
> > >
> > > Could anybody give some explanation? Thank you.
> > >
> > > A Rusli
> > > Physics Department
> > > Parahyangan Catholic University
> > > Bandung, Indonesia

Ludwik Kowalski
Let the perfect not be the enemy of the good.