A History of the Theories of Aether and Electricity

A History of the Theories of Aether and Electricity  (1910) 
by Edmund Taylor Whittaker

Authoritative reference work covering the development of electromagnetism, optics, and the aether theories prior to the development of relativity and quantum mechanics

DUBLIN UNIVERSITY PRESS SERIES.


A HISTORY

OF THE

THEORIES OF AETHER AND ELECTRICITY

FROM THE AGE OF DESCARTES TO THE CLOSE OF
THE NINETEENTH CENTURY
.

BY
E. T. WHITTAKER,
Hon. Sc. D. (Dubl.); F. R. S.; Royal Astronomer of Ireland.

LONGMANS, GREEN, AND CO.,
39 PATERNOSTER ROW, LONDON,
NEW YORK, BOMBAY, AND CALCUTTA.
HODGES, FIGGIS, & CO., Ltd., DUBLIN.
1910.

DUBLIN:
PRINTED AT THE UNIVERSITY PRESS,
BY PONSONBY AND GIBBS.

The author desires to record his gratitude to Mr. W. W. Rouse Ball, Fellow of Trinity College, Cambridge, and to Professor W. McF. Orr, F. R. S., of the Royal College of Science for Ireland; these friends have read the proof-sheets, and have made many helpful suggestions and criticisms.

Thanks are also due to the Board of Trinity College, Dublin, for the financial assistance which made possible the publication of the work.

Contents.

The Theory of the Aether in the Seventeenth Century.

Page

Matter and aether,
....................................................................................................................................................................................................................................................
1
The physical writings of Descartes,
....................................................................................................................................................................................................................................................
2
Early history of magnetism : Petrus Peregrinus, Gilbert, Descartes,
....................................................................................................................................................................................................................................................
7
Fermat attacks Descartes' theory of light: the principle of least time,
....................................................................................................................................................................................................................................................
10
Hooke's undulatory theory: the advance of wave-fronts,
....................................................................................................................................................................................................................................................
11
Newton overthrows Hooke's theory of colours,
....................................................................................................................................................................................................................................................
15
Conception of the aether in the writings of Newton,
....................................................................................................................................................................................................................................................
17
Newton's theories of the periodicity of homogeneous light, and of fits of easy transmission,
....................................................................................................................................................................................................................................................
20
The velocity of light: Galileo, Roemer,
....................................................................................................................................................................................................................................................
21
Huygens' Traité de la lumière: his theories of the propagation of waves, and of crystalline optics,
....................................................................................................................................................................................................................................................
22
Newton shows that rays obtained by double refraction have sides: his objections to the undulatory theory,
....................................................................................................................................................................................................................................................
28

Electric and Magnetic Science, Prior to the Introduction of the Potentials.

The electrical researches of Gilbert: the theory of emanations,
....................................................................................................................................................................................................................................................
29
State of physical science in the first half of the eighteenth century,
....................................................................................................................................................................................................................................................
32
Gray discovers electric conduction: Desaguliers,
....................................................................................................................................................................................................................................................
37
The electric fluid,
....................................................................................................................................................................................................................................................
38
Du Fay distinguishes vitreous and resinous electricity,
....................................................................................................................................................................................................................................................
39
Nollet's effluent and affluent streams,
....................................................................................................................................................................................................................................................
40
The Leyden phial,
....................................................................................................................................................................................................................................................
41
The one-fluid theory: ideas of Watson and Franklin,
....................................................................................................................................................................................................................................................
42
Final overthrow by Aepinus of the doctrine of effluvia,
....................................................................................................................................................................................................................................................
48
Priestley discovers the law of electrostatic force,
....................................................................................................................................................................................................................................................
50
Cavendish,
....................................................................................................................................................................................................................................................
51
Michell discovers the law of magnetic force,
....................................................................................................................................................................................................................................................
54
The two-fluid theory: Coulomb,
....................................................................................................................................................................................................................................................
56
Limited mobility of the magnetic fluids,
....................................................................................................................................................................................................................................................
58
Poisson's mathematical theory of electrostatics,
....................................................................................................................................................................................................................................................
59
The equivalent surface- and volume-distributions of magnetism: Poisson's theory of magnetic induction,
....................................................................................................................................................................................................................................................
64
Green's Nottinghamn memoir,
....................................................................................................................................................................................................................................................
65

Galvanism, from Galvani to Ohm.

Sulzer's discovery,
....................................................................................................................................................................................................................................................
67
Galvanic phenomena,
....................................................................................................................................................................................................................................................
68
Rival hypotheses regarding the galvanic fluid,
....................................................................................................................................................................................................................................................
70
The voltaic pile,
....................................................................................................................................................................................................................................................
72
Nicholson and Carlisle decompose water voltaically,
....................................................................................................................................................................................................................................................
75
Davy's chemical theory of the pile,
....................................................................................................................................................................................................................................................
76
Grothuss' chain,
....................................................................................................................................................................................................................................................
78
De La Rive's hypothesis,
....................................................................................................................................................................................................................................................
79
Berzelius' scheme of electro-chemistry,
....................................................................................................................................................................................................................................................
80
Early attempts to discover a connexion between electricity and magnetism,
....................................................................................................................................................................................................................................................
83
Oersted's experiment: his explanation of it,
....................................................................................................................................................................................................................................................
85
The law of Biot and Savart,
....................................................................................................................................................................................................................................................
86
The rescarches of Ampère on electrodynamics,
....................................................................................................................................................................................................................................................
87
Seebeck's phenomenon,
....................................................................................................................................................................................................................................................
90
Davy's researches on conducting power,
....................................................................................................................................................................................................................................................
94
Ohm's theory: electroscopic force,
....................................................................................................................................................................................................................................................
95

The Luminiferous Medium, from Bradley to Fresnel.

Bradley discovers aberration,
....................................................................................................................................................................................................................................................
99
John Bernoulli's model of the aether,
....................................................................................................................................................................................................................................................
100
Maupertuis and the principle of least action,
....................................................................................................................................................................................................................................................
102
Views of Fuler, Courtivron, Melvill,
....................................................................................................................................................................................................................................................
104
Young defends the undulatory theory, and explains the colours of thin plates,
....................................................................................................................................................................................................................................................
105
Laplace supplies a corpuscular theory of double refraction,
....................................................................................................................................................................................................................................................
109
Young proposes a dynamical theory of light in crystals,
....................................................................................................................................................................................................................................................
110
Researches of Malus on polarization,
....................................................................................................................................................................................................................................................
111
Recognition of biaxal crystals,
....................................................................................................................................................................................................................................................
113
Fresnel successfully explains diffraction,
....................................................................................................................................................................................................................................................
113
His theory of the relatire motion of aether and matter,
....................................................................................................................................................................................................................................................
115
Young suggests the transversality of the vibrations of light,
....................................................................................................................................................................................................................................................
121
Fresnel discusses the dynamics of transverse vibrations
....................................................................................................................................................................................................................................................
123
Fresnel's theory of the propagation of light in crystals,
....................................................................................................................................................................................................................................................
123
Hamilton predicts conical refraction,
....................................................................................................................................................................................................................................................
131
Fresnel's theory of reflexion,
....................................................................................................................................................................................................................................................
133

The Aether as an Elastic Solid.

Astronomical objection to the elastic-solid theory: Stokes' hypothesis.
....................................................................................................................................................................................................................................................
137
Navier and Cauchy discover the equation of vibration of an elastic solid,
....................................................................................................................................................................................................................................................
139
Poisson distinguishes condensational and distortional waves,
....................................................................................................................................................................................................................................................
141
Cauchy's first and second theories of light in crystals,
....................................................................................................................................................................................................................................................
143
Cauchy's first theory of reflexion,
....................................................................................................................................................................................................................................................
145
His second theory of reflexion,
....................................................................................................................................................................................................................................................
147
The theory of reflexion of MacCullagh and Neumann,
....................................................................................................................................................................................................................................................
148
Green discovers the correct conditions at the boundaries,
....................................................................................................................................................................................................................................................
151
Green's theory of reflexion : objections to it,
....................................................................................................................................................................................................................................................
152
MacCullagh introduces a new type of elastic solid,
....................................................................................................................................................................................................................................................
154
W. Thomson's model of a rotationally-elastic body,
....................................................................................................................................................................................................................................................
157
Cauchy's third theory of reflexion: the contractile aether,
....................................................................................................................................................................................................................................................
158
Later work of W. Thomson and others on the contractile aether,
....................................................................................................................................................................................................................................................
159
Green's first and second theories of light in crystals,
....................................................................................................................................................................................................................................................
161
Influence of Green,
....................................................................................................................................................................................................................................................
167
Researches of Stokes on the relation of the direction of vibration of light to its plane of polarization,
....................................................................................................................................................................................................................................................
168
The hypothesis of aeolotropic inertia,
....................................................................................................................................................................................................................................................
171
Rotation of the plane of polarization of light by active bodies,
....................................................................................................................................................................................................................................................
173
MacCullagh's theory of natural rotatory power,
....................................................................................................................................................................................................................................................
175
MacCullagh's and Cauchy's theory of metallic retlexion,
....................................................................................................................................................................................................................................................
177
Extension of the elastic-solid theory to metals,
....................................................................................................................................................................................................................................................
179
Lord Rayleigh's objection,
....................................................................................................................................................................................................................................................
181
Cauchy's theory of dispersion,
....................................................................................................................................................................................................................................................
182
Boussinesq's elastic-solid theory,
....................................................................................................................................................................................................................................................
185

Faraday.

Discovery of induced currents: lines of magnetic force,
....................................................................................................................................................................................................................................................
189
Self-induction,
....................................................................................................................................................................................................................................................
193
Identity of frictional and voltaic electricity: Faraday's views on the nature of electricity,
....................................................................................................................................................................................................................................................
194
Electro-chemistry,
....................................................................................................................................................................................................................................................
197
Controversy between the adherents of the chemical and contact hypotheses,
....................................................................................................................................................................................................................................................
201
The properties of dielectrics,
....................................................................................................................................................................................................................................................
206
Theory of dielectric polarization : Faraday, W. Thomson, and Mosgotti,
....................................................................................................................................................................................................................................................
211
The connexion between magnetism and light,
....................................................................................................................................................................................................................................................
213
Airy's theory of magnetic rotatory polarization,
....................................................................................................................................................................................................................................................
214
Faraday's Thoughts on Ray-Vibrations,
....................................................................................................................................................................................................................................................
217
Researches of Faraday and Plücker on diamagnetism,
....................................................................................................................................................................................................................................................
218

The Mathematical Electricians of the Middle of the Nineteenth Century.

F. Neumann's theory of induced currents: the electrodynamic potential,
....................................................................................................................................................................................................................................................
222
W. Weber's theory of electrons,
....................................................................................................................................................................................................................................................
225
Riemann's law,
....................................................................................................................................................................................................................................................
231
Proposals to modify the law of gravitation,
....................................................................................................................................................................................................................................................
232
Weber's theory of paramagnetism and diamagnetism: later theories,
....................................................................................................................................................................................................................................................
234
Joule's law: energetics of the voltaic cell,
....................................................................................................................................................................................................................................................
239
Researches of Helmholtz on electrostatic and electrodynamic energy,
....................................................................................................................................................................................................................................................
242
W. Thomson distinguishes the circuital and irrotational magnetic vectors,
....................................................................................................................................................................................................................................................
244
His theory of magnecrystallic action,
....................................................................................................................................................................................................................................................
245
His formula for the energy of a magnetic field,
....................................................................................................................................................................................................................................................
247
Extension of this formula to the case of fields produced by currents,
....................................................................................................................................................................................................................................................
249
Kirchhoff identifies Ohm's electroscopic force with electrostatic potential,
....................................................................................................................................................................................................................................................
251
The discharge of a Leyden jar: W. Thomson's theory,
....................................................................................................................................................................................................................................................
253
The velocity of electricity and the propagation of telegraphic signals,
....................................................................................................................................................................................................................................................
254
Clausius' law of force between electric charges : crucial experiments,
....................................................................................................................................................................................................................................................
261
Nature of the current,
....................................................................................................................................................................................................................................................
263
The thermo-electric researches of Peltier and W. Thomson,
....................................................................................................................................................................................................................................................
264

Maxwell.

Gauss and Riemann on the propagation of electric actions,
....................................................................................................................................................................................................................................................
268
Analogies suggested by W. Thomson,
....................................................................................................................................................................................................................................................
269
Maxwell's hydrodynamical analogy,
....................................................................................................................................................................................................................................................
271
The vector potential,
....................................................................................................................................................................................................................................................
273
Linear and rotatory interpretations of magnetism,
....................................................................................................................................................................................................................................................
274
Maxwell's mechanical model of the electromagnetic field,
....................................................................................................................................................................................................................................................
276
Electric displacement,
....................................................................................................................................................................................................................................................
279
Similarity of electric vibrations to those of light,
....................................................................................................................................................................................................................................................
281
Connexion of refractive index and specific inductive capacity,
....................................................................................................................................................................................................................................................
283
Maxwell's memoir of 1864,
....................................................................................................................................................................................................................................................
284
The propagation of electric disturbances in crystals and in metals,
....................................................................................................................................................................................................................................................
288
Anomalous dispersion,
....................................................................................................................................................................................................................................................
291
The Maxwell-Sellmeier theory of dispersion,
....................................................................................................................................................................................................................................................
292
Imperfections of the electromagnetic theory of light,
....................................................................................................................................................................................................................................................
295
The theory of L. Lorenz,
....................................................................................................................................................................................................................................................
297
Maxwell's theory of stress in the electric field,
....................................................................................................................................................................................................................................................
300
The pressure of radiation,
....................................................................................................................................................................................................................................................
303
Maxwell's theory of the magnetic rotation of light,
....................................................................................................................................................................................................................................................
307

Models of the Aether.

Analogies in which a rotatory character is attributed to magnetism,
....................................................................................................................................................................................................................................................
310
Models in which magnetic force is represented as a linear velocity,
....................................................................................................................................................................................................................................................
311
Researches of W. Thomson, Bjerknes, and Leahy, on pulsating and oscillating bodies,
....................................................................................................................................................................................................................................................
316
MacCullagh's quasi-elastic solid as a model of the electric medium,
....................................................................................................................................................................................................................................................
318
The Tall effect,
....................................................................................................................................................................................................................................................
320
Models of Riemann and FitzGerald,
....................................................................................................................................................................................................................................................
324
Vortex-atoms,
....................................................................................................................................................................................................................................................
326
The vortex-sponge theory of the aether: researches of W. Thomson, FitzGerald, and Hicks,
....................................................................................................................................................................................................................................................
327

The Followers of Maxwell.

Helmholtz and H. A. Lorentz supply an electromagnetic theory of reflexion,
....................................................................................................................................................................................................................................................
337
Crucial experiments of Helmholtz and Schiller,
....................................................................................................................................................................................................................................................
338
Convection-currents: Rowland's experiments,
....................................................................................................................................................................................................................................................
339
The moving charged sphere: researches of J.J. Thomson, FitzGerald, and Heaviside,
....................................................................................................................................................................................................................................................
310
Conduction of rapidly-alternating currents,
....................................................................................................................................................................................................................................................
344
FitzGerald devises the magnetic radiator,
....................................................................................................................................................................................................................................................
345
Poynting's theorem,
....................................................................................................................................................................................................................................................
347
Poynting and J.J. Thomson develop the theory of moving lines of force,
....................................................................................................................................................................................................................................................
349
Mechanical momentum in the electromagnetic field,
....................................................................................................................................................................................................................................................
352
Now derivation of Maxwell's equations by Hertz,
....................................................................................................................................................................................................................................................
333
Hertz's assumptions and Weber's theory,
....................................................................................................................................................................................................................................................
356
Experiments of Hertz on electric waves,
....................................................................................................................................................................................................................................................
357
The memoirs of Hertz and Heaviside on fields in which material bodies are in motion,
....................................................................................................................................................................................................................................................
365
The current of dielectric convection,
....................................................................................................................................................................................................................................................
367
Kerr's magneto-optic phenomenon,
....................................................................................................................................................................................................................................................
368
Rowland's theory of magneto-optics,
....................................................................................................................................................................................................................................................
369
The rotation of the plane of polarization in naturally active bodies,
....................................................................................................................................................................................................................................................
370

Conduction in Solutions and Gases, from Faraday to J. J. Thomson.

The hypothesis of Williamson and Clausius,
....................................................................................................................................................................................................................................................
372
Migration of the ions,
....................................................................................................................................................................................................................................................
373
The researches of Hittorf and Kohlrausch,
....................................................................................................................................................................................................................................................
374
Polarization of electrodes,
....................................................................................................................................................................................................................................................
375
Electrocapillarity,
....................................................................................................................................................................................................................................................
376
Single differences of potential,
....................................................................................................................................................................................................................................................
379
Helmholtz' theory of concentration-cells,
....................................................................................................................................................................................................................................................
381
Arrhonius' hypothesis,
....................................................................................................................................................................................................................................................
383
The researches of Nernst,
....................................................................................................................................................................................................................................................
386
Earlier investigations of the discharge in rarefied gases,
....................................................................................................................................................................................................................................................
390
Faraday observes the dark space,
....................................................................................................................................................................................................................................................
391
Researches of Plücker, Hittorf, Goldstein, and Varley, on the cathode rays,
....................................................................................................................................................................................................................................................
393
Crookes and the fourth state of matter,
....................................................................................................................................................................................................................................................
394
Objections and alternatives to the charged-particle theory of cathode rays,
....................................................................................................................................................................................................................................................
395
Giese's and Schuster's ionic theory of conduction in gases,
....................................................................................................................................................................................................................................................
397
J.J. Thomson measures the velocity of cathode rays,
....................................................................................................................................................................................................................................................
400
Discovery of X-rays : hypotheses regarding them,
....................................................................................................................................................................................................................................................
401
Further researches of J.J. Thomson on cathode rays: the ratio m/e,
....................................................................................................................................................................................................................................................
404
Vitreous and resinous electricity,
....................................................................................................................................................................................................................................................
406
Determination of the ionic charge by J. J. Thomson,
....................................................................................................................................................................................................................................................
407
Becquerel's radiation: discovery of radio-active substances,
....................................................................................................................................................................................................................................................
408

The Theory of Aether and Electrons in the Closing Years of the Nineteenth Century.

Stokes' theory of aethereal motion near moving bodies,
....................................................................................................................................................................................................................................................
411
Astronomical phenomena in which the velocity of light is involved,
....................................................................................................................................................................................................................................................
413
Crucial experiments relating to the optics of moving bodies,
....................................................................................................................................................................................................................................................
416
Lorentz' theory of electrons,
....................................................................................................................................................................................................................................................
419
The current of dielectric convection: Röntgon's experiment,
....................................................................................................................................................................................................................................................
426
The electronic theory of dispersion,
....................................................................................................................................................................................................................................................
428
Deduction of Fresnel's formula fron the theory of electrons,
....................................................................................................................................................................................................................................................
430
Experimental verification of Lorentz' hypothesis,
....................................................................................................................................................................................................................................................
431
FitzGerald's explanation of Michelson's experiment,
....................................................................................................................................................................................................................................................
432
Lorentz treatise of 1895,
....................................................................................................................................................................................................................................................
433
Expression of the potentials in terms of the electronic charges,
....................................................................................................................................................................................................................................................
436
Further experiments on the relative motion of earth and aether,
....................................................................................................................................................................................................................................................
437
Extension of Lorentz transformation : Larmor discovers its connexion with FitzGerald's hypothesis of contraction,
....................................................................................................................................................................................................................................................
440
Examination of the supposed primacy of the original variables: fixity relative to the aether: the principle of relativity,
....................................................................................................................................................................................................................................................
444
The phenomenon of Zeeman,
....................................................................................................................................................................................................................................................
449
Connexion of Zeeman's effect with the magnetic rotation of light
....................................................................................................................................................................................................................................................
452
The optical properties of metals,
....................................................................................................................................................................................................................................................
454
The electronic theory of metals,
....................................................................................................................................................................................................................................................
456
Thermionics,
....................................................................................................................................................................................................................................................
464
Index,
....................................................................................................................................................................................................................................................
470

Memorandum on Notation


Vectors are denoted by letters in clarendon type, as E.

The three components of a vector E are denoted by Ex, Ey, Ez, and the magnitude of the vector is denoted by E, so that

The vector product of two vectors E and H, which is denoted by [E.H], is the vector whose components are (EyHz - EzHy, EzHx - ExHz, ExHy - EyHx). Its direction is at right angles to the direction of E and H, its magnitude is represented by twice the area of the triangle formed by them.

The scalar product of two vectors E and H is ExHx + EyHy + EzHz. It is denoted by (E.H).

The quantity is denoted by div E.

The vector whose components are

[errata 1]

is denoted by curl E.


If V denote a scalar quantity, the vector whose components are is denoted by grad V.

The symbol ∇ is used to denote the sector operator whose components are , , .

Differentiation with respect to the time is frequently indicated by a dot placed over the symbol of the variable which is differentiated.

This work is in the public domain in the United States because it was published before January 1, 1926.


The author died in 1956, so this work is also in the public domain in countries and areas where the copyright term is the author's life plus 60 years or less. This work may also be in the public domain in countries and areas with longer native copyright terms that apply the rule of the shorter term to foreign works.

 


NotesEdit

  1. Original:   was amended to