Dear John,
What is wrong with honouring Sohnke by using his name for something
that he first saw a point in defining, and in investigating the properties
resulting from that definition? Why insist that we should instead replace
his name by an adjective or a circumlocution? What would we say if someone
outside our field asked us not to talk about a Bragg reflection, or the
Ewald sphere, or the Laue method, but to use instead some clever adjective
or a noun-phrase as long as the name of a Welsh village to explain what
these mean?
Again, I think we should have a bit more respect here. When there are
simple adjectives to describe a mathematical properties, the mathematical
vocabulary uses it (like a "normal" subgroup). However, when someone has
seen that a definition by a conjunction of properties (i.e. something
describable by a sentence) turns out to characterise objects that have much
more interesting properties than just those by which they were defined, then
they are often called by the name of the mathematician who first saw that
there is more to them than what defines them. Examples: Coxeter groups, or
Lie algebras, or the Leech lattice, or the Galois group of a field, the
Cayley tree of a group ... . It is the name of the first witness to a
mathematical phenomenon, just as we call chemical reactions by the name of
the chemist who saw that mixing certain chemicals together led not just to a
mixture of those chemicals.
So why don't we give Sohnke what belongs to him, just as we expect
other scientists to give to Laue, Bragg and Ewald what we think belongs to
them? Maybe students would not be as refractory to the idea as might first
be thought.
With best wishes,
Gerard.
--
On Fri, May 02, 2014 at 05:42:34PM +0100, Jrh Gmail wrote:
> Dear George
> My student class would not find that IUCr dictionary definition helpful. What
> they do find helpful is to state that they cannot contain an inversion or a
> mirror.
> To honour Sohnke is one thing but is it really necessary as a label? You're
> from Huddersfield I am from Wakefield ie let's call a spade a spade (not a
> 'Black and Decker').
> Cheers
> John
>
> Prof John R Helliwell DSc
>
> > On 2 May 2014, at 17:01, George Sheldrick <gshe...@shelx.uni-ac.gwdg.de>
> > wrote:
> >
> > In my program documentation I usually call these 65 the Sohnke space
> > groups, as defined by the IUCr:
> > http://reference.iucr.org/dictionary/Sohnke_groups
> >
> > George
> >
> >
> >> On 05/02/2014 02:35 PM, Jim Pflugrath wrote:
> >> After all this discussion, I think that Bernhard can now lay the claim
> >> that these 65 space groups should really just be labelled the "Rupp" space
> >> groups. At least it is one word.
> >>
> >> Jim
> >>
> >> From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Bernhard
> >> Rupp [hofkristall...@gmail.com]
> >> Sent: Friday, May 02, 2014 3:04 AM
> >> To: CCP4BB@JISCMAIL.AC.UK
> >> Subject: Re: [ccp4bb] Confusion about space group nomenclature
> >> ….
> >>
> >> Enough of this thread.
> >>
> >> Over and out, BR
> >
> >
> > --
> > Prof. George M. Sheldrick FRS
> > Dept. Structural Chemistry,
> > University of Goettingen,
> > Tammannstr. 4,
> > D37077 Goettingen, Germany
> > Tel. +49-551-39-33021 or -33068
> > Fax. +49-551-39-22582
