Dear Gerard I am duly reprimanded . You are quite correct . Have a good weekend John
Prof John R Helliwell DSc > On 2 May 2014, at 18:16, Gerard Bricogne <[email protected]> wrote: > > 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 <[email protected]> >>> 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 [[email protected]] on behalf of Bernhard >>>> Rupp [[email protected]] >>>> Sent: Friday, May 02, 2014 3:04 AM >>>> To: [email protected] >>>> 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
