Re: Query about intrinsic verus orbital angular momentum

<torre@xxxxxxxxxx> wrote in message
news:bf3701bb-6d34-47f3-a243-ed29a81a1d39@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Related to this, how do we "know" that intrinsic spin does not in
fact
involve rotation on an exceptionally small scale beyond the direct
reach
of our experimentation? =A0Is this just supposition?


Ultimately, one should address these issues from the
point of view of quantum field theory.

But, I think a decisive argument - strictly in the context
of non-relativistic quantum mechanics - is simply that one
can show angular momentum of the r x p type (associated
with rotation) can have only integer quantum numbers. The
electron, of course has half-integer quantum numbers; its
spin angular momentum must therefore be interpreted in some
other way.

charlie

Hi Charlie,

Thank you for the post. What you have done, effectively, is asserted as
an answer, the main query I am posing. You say "one can show angular
momentum of the r x p type (associated with rotation) can have only
integer quantum numbers." My question simply, is, HOW does one show
this? Especially, how does one *exclude* spin 1/2 from also being of
the rxp type?

As a counterpoint, take a look at Hans Devries' Figure 1.5 at
http://physics-quest.org/Book_Chapter_EM_basic.pdf. This seems to
suggest that one can also consider half-integer spins to also be of the
rxp type. You thoughts?

Thanks,

Jay

.

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