Elegance in Science: The beauty of simplicity

290 Pages·2010·2.35 MB·English

by  Ian Glynn

ELEGANCE IN SCIENCE
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the beauty of
simplicity
ian glynn
1
3
Great Clarendon Street, Oxford ox26dp
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© Ian Glynn 2010
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First published 2010
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Library of Congress Control Number: 2009943759
Typeset by SPI Publisher Services, Pondicherry, India
Printed in Great Britain
on acid-free paper by
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ISBN 978–0–19–957862–7
1 3 5 7 9 10 8 6 4 2
contents
Illustrations vii
Preface xv
1. The meaning of elegance 1
2. Celestial mechanics: the route to Newton 18
3. Bringing the heavens down to earth 37
4. So what is heat? 61
5. Elegance and electricity 87
6. Throwing light on light: with the story of
Thomas Young 106
7. How do nerves work? 140
8. Information handling in the brain 170
9. The genetic code 196
10. Epilogue: a cautionary tale 232
Appendix to Chapter 4 235
Notes 245
Index 263
v
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illustrations
1. Covering a grid with dominoes. 2
2. Pythagoras’ theorem. 5
3. Egyptian tile pattern. 5
4. Construction necessary for Euclid’s proof of
Pythagoras’ theorem. 6
5. Elegant proof of Pythagoras’ theorem. 6
6. Archimedes’ proof that the area of a circle is equal to pr2. 7
7. An Archimedean screw used for pumping water. From
Chambers’ Encyclopaedia,1875. 10
8. Olbers’ paradox. 11
9. William Harvey’s demonstration that blood circulates.
From Harvey’s De Motu Cordis et Sanguinis,1628. 14
10. Kepler’s diagram showing that the relative sizes of
circles that circumscribe a triangle, and that can just
be inscribed in that triangle, are much the same as
the relative sizes of the orbits of Saturn and Jupiter. 23
11. The fi ve ‘Platonic solids’. 23
12. An elliptic orbit with the Sun at one of the foci. 32
13. Diagram illustrating Kepler’s second law. 32
14. Galileo’s experiments, with balls rolling down smooth
almost friction-free planes, that led him to the
concept of inertia. 42
15. Galileo’s experiment showing parabolic motion. 44
vii
illustrations
16. Diagram illustrating Newton’s law of universal
gravitation. 56
17. Diagram showing the three kinds of motion
of the Earth. 58
18. Plan of fi replace modifi ed by Rumford. From Of Chimney
Fireplaces, in The Collected Works of Count Rumford, ed.
Sanborn C. Brown, 1968–70, vol. II, pp. 221–95. 70
19. Rumford’s modifi cation of a chimney. From Of Chimney
Fireplaces, in The Collected Works of Count Rumford, ed.
Sanborn C. Brown, 1968–70, vol. II, pp. 221–95. 71
20. Rumford’s cannon-boring experiments. From Rumford’s
account in Philosophical Transactions of the Royal Society,
London (1798)88:80–102. 74
21. Joule’s determination of the mechanical equivalent of heat.
From A.W. Barton (1938)A Text Book on Heat, p. 167,
Figure 59, Longmans Green & Co. Reproduced with
permission of Pearson Education, Harlow. 85
22. The fi rst two electric motors. From M. Faraday (1844)
Experimental Researches in Electricity, vol. II, Plate IV,
Figure 1. John Edward Taylor, London. 93
23. The fi rst induction coil. Based on a drawing in
M. Faraday (1832)Philosophical Transactions of the
Royal Society, London,116:125–62. 95
24. ‘Arago’s wheel’. 97
25. The top of a page of Faraday’s diary showing a sketch
of the fi rst dynamo. From Faraday’s diary of
28 October 1831. Reproduced with permission of the
Royal Institution, London. 98
26. Faraday found that a galvanometer connected between
the rim of the disc and its rotating axle showed a strong
current. 98
27. Faraday’s experiment to investigate the relation between
the chemical change occurring in an electrolytic
cell and the total charge passed through the cell. 101
viii
illustrations
28. Experiments with a ripple tank showing the behaviour
of straight waves when they meet a barrier with narrow
or wide openings. From P.A. Tipler and G. Mosca (2008)
Physics for Scientists and Engineers,6th edn, Figures 15-23
&25. Reproduced with permission of
W.H. Freeman, New York. 115
29. The behaviour of a refl ected beam of light. 115
30. The behaviour of a refracted beam of light. 116
31. Huygens’ construction explaining the propagation of a
primary wavefront. From P.A. Tipler and G. Mosca
(2008)Physics for Scientists and Engineers,6th edn,
Figure 31-7. Reproduced with permission of
W.H. Freeman, New York. 117
32. A diagram, based on Huygens’ construction,
showing how the slowing of light waves as they
obliquely enter a denser medium changes the
direction of the wavefronts. 117
33. Longitudinal and transverse waves. 119
34. The addition of two similar waves with slightly different
frequencies to give ‘beats’. 121
35. Newton’s arrangement for producing a fi lm of air that is
thin but of known thickness. 122
36. Diagram from Newton’s Opticks showing the arrangement
of colours in Newton’s rings. 123
37. Thomas Young’s explanation of the effects of phase
difference on the interference between two identical
waves. 124
38. Interference between two equal sets of water waves.
The left-hand side is from a drawing by Thomas Young.
From T. Young (1807)A Course of Lectures on Natural
Philosophy and the Mechanical Arts, vol. 1, Plate XX,
Figure 267. The right-hand side is a photograph of a
modern ripple tank. From A.W. Barton (1939)Text Book
of Light, Plate IV, Figure 3, Longmans Green & Co,
ix