Subject: Re: CCL:orbitals and reality

From: Eric Scerri <scerri{at}chem.ucla.edu>
Date: Wed, 23 Feb 2005 00:36:09 -0800

>
>It doesn't seem inconceivable to me that one day high-energy 
>physicist  will decompose the electron in the same way as they 
>decomposed the  proton. Would you then still say that electrons are 
>"real"?
>--
>------------------------------------------------------------------------ 
>-------
>Konrad Hinsen

With all respect Konrad, this is reductionism taken to a ridiculous extreme.

Do the beloved molecules of the chemist cease to exist just because 
they can be decomposed into atoms?  No they dont!

Molecules are just as real as atoms, organism are just are real as 
molecules and societies are just as real as individuals. Or is there 
just one reality which keeps shrinking down to smaller and smaller 
dimensions?

eric scerri

-- 

Dr. Eric Scerri ,
UCLA,
Department of Chemistry & Biochemistry,
607 Charles E. Young Drive East,
Los Angeles,  CA 90095-1569
USA

E-mail :   scerri{at}chem.ucla.edu
tel:  310 206 7443
fax:  310 206 2061
Web Page:    http://www.chem.ucla.edu/dept/Faculty/scerri/index.html

Editor  of  Foundations of Chemistry
http://www.kluweronline.com/issn/1386-4238

Also see International Society for the Philosophy of Chemistry
http://ispc.sas.upenn.edu/

---

From: khinsen_at_cea.fr
Date: Wed, 23 Feb 2005 09:22:26 +0100

On 20.02.2005, at 00:13, Eric Scerri wrote:

> To my mind this is a rather disappointing attitude.  The emergence of  
> philosophical discussions among scientists is surely a sign of change  
> occurring and should be welcomed as a respite from the day-to-day work  
> and as an opportunity for practitioners from different parts of the  
> field to engage in fruitful discussion, more widely than in the normal  
> course of events.

I agree!

> It seems to be that there are some rather formidable grounds for  
> believing in the real physical existence of electrons as opposed to  
> orbitals even though neither are directly observable. Yes we only  
> observe properties of electrons but we then infer the existence of a  
> particle that gives rise to these properties.

What I wanted to point out is that there is no *fundamental* difference  
between electrons and orbitals as far as their "existence" is  
concerned. The difference is one of quantity rather than quality,  
although I agree of course that the difference is huge.

I could have taken a more extreme example than electrons. My office  
chair, for example. The "office chair" model explains a huge number of  
my personal sensorial experiences, and also agrees with the experience  
of other people as they communicate it to me. For all practical  
purposes it "exists", but still it is just a mental model that helps me  
organize my impressions.

> Starting with J.J. Thomson in 1897, if not before, many properties of  
> electrons have been 'observed' such as its mass, charge and spin.  
> Would it not be a miracle if all these experiments pointed towards the  
> existence of the electron and yet there was no such particle (The no  
> miracle argument for realism).

Define "particle" and "miracle"...

> There have been a number of very influential theories of the electron  
> starting with Thomson, Rutherford, Bohr, Schrodinger, Dirac etc. Even  
> though these theories may have described the electron in different  
> ways there is little doubt about the continuity of reference.  In  
> other words there is

No, because all those theories are built on the same mental image of a  
"particle".

> In addition there has never been any feature within these theories  
> that have specifically ruled out the physical existence of the  
> electron.

There couldn't be according to my view, as "physical existence" is not  
a property that can be verified and thus has no place in a scientific  
theory.

Perhaps electrons are not the best illustration of what I am trying to  
get at. Let's consider protons. Do they "exist"? Or are they merely a  
convenient label for bound states of three quarks? Do the quarks  
"exist", or are they merely a convenient concept for explaining the  
properties of protons and neutrons, given that there is no evidence for  
quarks in isolation?

It doesn't seem inconceivable to me that one day high-energy physicist  
will decompose the electron in the same way as they decomposed the  
proton. Would you then still say that electrons are "real"?
--
------------------------------------------------------------------------ 
-------
Konrad Hinsen
Laboratoire Leon Brillouin, CEA Saclay,
91191 Gif-sur-Yvette Cedex, France
Tel.: +33-1 69 08 79 25
Fax: +33-1 69 08 82 61
E-Mail: khinsen_at_cea.fr
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---

From: khinsen #%# cea.fr
Date: Wed, 23 Feb 2005 20:03:14 +0100

> they can be decomposed into atoms?  No they dont!

They are certainly less fundamental for being decomposable. But then, I  
am a physicist, so my view on molecules is probably different from a  
chemist's view.

> just one reality which keeps shrinking down to smaller and smaller  

The point I am trying to make is that "reality" has no place in a  
scientific theory. The concept belongs to the realm of metaphysics. In  
my personal metaphysical world view, molecules, atoms, organisms, and  
societies are real, part of one single reality of which we only get  
imperfect information through observation. But there are other  
metaphysical world views which are just as compatible with the current  
set of scientific knowledge. By questioning the reality of things like  
electrons, I was mostly playing devil's advocate. I believe that when  
discussing a controversial issue such as the reality of orbitals, it is  
best to leave metaphysical issues aside and concentrate on what one can  
or cannot say about orbitals within a scientific theory.
--
------------------------------------------------------------------------ 
-------
Konrad Hinsen
Laboratoire Leon Brillouin, CEA Saclay,
91191 Gif-sur-Yvette Cedex, France
Tel.: +33-1 69 08 79 25
Fax: +33-1 69 08 82 61
E-Mail: khinsen #%# cea.fr
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