SENIORS GROUP
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LUNCHTIME RENDEZVOUS: Clubhouse
Wednesday the 26th of March 14
From 1000 to 1500 hours
Location:
Clubhouse, Daniel Stewart’s and Melville College
Inverleith Playing Fields, 523 Ferry Road, Edinburgh
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Programme:
1000
1025
1030
Arrival and coffee/tea [first floor]
Welcome and Introduction by the Seniors Group Coordinator [ground floor]
Lecture Who was James Clerk Maxwell? by Dr John Arthur, Past Technical
Director of Thales MESL and currently Trustee, The James Clerk Maxwell
Foundation, 14 India Street, Edinburgh, Scotland [ground floor].
1125 Lecture Rectifying the Brewster Kaleidoscope by Mr Philip Bradfield, formerly
Senior Lecturer in Physics and Computer Science, The University of
Wolverhampton, England [ground floor].
1220 Four Course Lunch with Wine (Waitress Service) with partners and friends [first
floor].
1500 Finish
This Lunchtime Rendezvous is primarily a social occasion for the Seniors Group but the
talks are intended to be of interest to all. Over coffee and lunch there will be an
opportunity to discuss possible future events of interest to Members.
The cost is given on the Booking Form and includes coffee and a four course lunch with
wine. Non Members are most welcome to attend. Please note that the completed
Booking Form must be received by the Seniors Group Coordinator by the date shown on
the Booking Form.
Abstracts:
Who was James Clerk Maxwell? by Dr John Arthur, BSc, PhD, FRSE, FREng, FInstP,
CPhys, FIET, CEng, SMIEEE, Past Technical Director of Thales MESL and currently
Trustee, The James Clerk Maxwell Foundation, 14 India Street, Edinburgh, Scotland.
While the name James Clerk Maxwell is familiar to everyone who has studied university
physics, he is largely unknown to the general public. Few of those who have actually
heard of him know that he was a Scot, let alone one who was born in Edinburgh and also
went to school and university there. He was a direct descendant of Lords and Baronets,
three family members were the close friends of Sir Walter Scott, and his relatives
managed to occupy a score or so of the most desirable residences in Edinburgh's New
Town. As well as other high achievements, his family circle brimmed with artistic and
mathematical genius, and more than a few were elected Fellows of the Royal Society of
Edinburgh. Although his most exalted legacy has been Maxwell's Equations, he also
solved the problem of the stability of Saturn's rings, derived ab initio the form of the
Maxwell-Boltzmann distribution, put the understanding of colour vision on a sound
footing, invented an ophthalmoscope, reproduced the first photographic colour image,
and showed engineers how to calculate the stresses in bridge structures, and much more.
The talk will delve into some interesting aspects of his family background, and of course,
some of his physics.
Rectifying the Brewster Kaleidoscope by Mr Philip Bradfield, MA, MSc, MInstP, CPhys,
FHEA, formerly Senior Lecturer in Physics and Computer Science, The University of
Wolverhampton, England.
Brewster did not really "invent" multi-mirror systems with his kaleidoscope (looking at
beautiful forms) - the pattern-generating properties of these had been known long before
his (ineffectual) Patent of 1817. Brewster was a very important figure in his time - a truly
prodigious experimenter, writer, publisher and proponent of educational and
social change. He successively achieved the posts of Principal of the United Colleges of
St Leonard and St Salvator, University of St Andrews, and Principal and Vice-Chancellor
of the University of Edinburgh.
In this lecture-demonstration, I intend to introduce both the wider history of the
kaleidoscope, and a novel graphical solution giving the results of the "awkward" generalangle case, not previously published. There will be an opportunity to "play"
(intelligently) with simple kaleidoscopes, and to enjoy a display of kaleidoscopes,
teleidoscopes and associated literature.
There is now a strong "crafts" interest, particularly in the USA, the late (Ms) Cozy Baker
being a leading figure, and with a USA-based Brewster Kaleidoscope Society. A taste of
these vigorous activities may be found at
http://www.thekaleidoscopebook.com/thescopebook/
The common treatments of the two-mirror dihedral (Brewster) kaleidoscope do
not tackle the general-angle case with much physical insight: Brewster himself
used the words "imperfect junction".
Just as W L Bragg clarified, with a physics perspective (c. 1912), Laue's Xray diffraction
by crystals, so I propose a more insightful analysis of the generalised kaleidoscope. The
great geometer Coxeter gave attention to the kaleidoscope problem, but without a
physics-based perspective, and Southall and others have presented laborious arguments,
but without much illumination.
The generation of yet more and more images as the dihedral angle closes will be fully
explained and illustrated. The crux is that the final images seen in the one or other of
the two mirrors generally DIFFER: the physical analysis I propose considers - as the
essence - the identification of the EXIT mirror for each image. We will indeed
understand Brewster's "imperfect junction".