The Oxford Science Lecture Series

Professor Eleanor Dodson FRS

University of York

“Mathematics in the Service of Crystallography”

 Dorothy Hodgkin Memorial Lecture 2011

University Museum, Oxford, 10th March 2011

The 2011 Dorothy Hodgkin Lecture was given by Prof. Eleanor Dodson FRS on the topic of mathematics in crystallography. Prof Dodson is an Emeritus Professor at the University of York having moved there from Oxford along with her husband, Prof. Guy Dodson who is also a crystallographer, and their 4 children. Despite science taking second place to raising her family, Prof. Dodson is one of the roughly 100 women to be appointed as a Fellow of the Royal Society (FRS).

Having worked alongside Dorothy from her arrival in the UK from Melbourne, Australia, Prof. Dobson was able to liberally pepper her lecture with both personal anecdotes and photographs of her time spent with Dorothy. A common theme was the inspiration that Dorothy provided at a time when the technical challenges were arriving thick and fast in virtually everything they did. The camaraderie generated within the group kept everyone going and getting along with people was a pre-requisite skill given the many night shifts spent trying to work things out from first principles. Emails and data exchange via USB stick to avoid personal interactions was simply not an option at the time. Everything tackled by the group was to achieve Dorothy’s aim of wanting to see the atoms. Thus Prof. Dodson felt that a more suitable and exciting secondary title for her talk would be:  “The joy of “seeing” and how to achieve it”.

In a fascinating talk that spanned a timescale from the 16th century to the present day, Prof. Dodson highlighted the mathematical concepts that form the basis of crystallography including those established when scientists examined the morphology of crystals using a visible light microscope. In this way space groups were defined long before an X-ray was ever incident on a crystal. In more recent times finite group theory has established the 230 space groups, building on this original work in the early 1800’s. Indeed, Katherine Lonsdale, another pioneering female crystallographer, and one of the first female FRS’s, systemised the space groups into a tabulated and publishable form and copies of her work in the International Tables are in daily demand by crystallographers worldwide.

Prof. Dodson highlighted many concepts that modern day crystallographers take for granted but which caused her many sleepless nights as she attempted to establish ways to systematically treat their data – positioning of the origin and the unit cell within a lattice being cases in point. She also placed in context the key developments which now form the basis of the technique – the Fourier series and the Patterson construction. The impact of even the early days of computing was brought home forcibly by the comment that solving the structure of penicillin (22 atoms and a rubidium) by hand took 4-5 years whereas a few years later B12 with its 54 atoms took 6 days.  Prof. Dodson was recruited to the Oxford group in the early 1960’s to provide a mathematical treatment of the matrices required for the most complex structure solution attempted to date – insulin with its 800 atoms, truly a protein rather than a small molecule and with the standard poor data that even now plague twenty first century protein crystallographers (some things don’t change!). With Prof. Dodson’s input the finals insulin maps were beautiful and at a resolution which allowed water molecules to be placed within the structure. Dorothy’s ultimate aim to see atoms had been achieved!

The talk ended on a lighter note with a variety of photographs of people associated with Dorothy’s work – a wonderful meander through the history of crystallography worldwide as seen from an Oxford perspective. 

The evening concluded with the Principal of Somerville College, Dr. Alice Prochaska,  thanking Prof. Dodson for her lecture and after questions the audience and speaker enjoyed a glass of wine amongst the museum exhibits.

Dr. Liz Duke,    Diamond Light Source.