Lodge-O · Source catalogue

A 14-page scan (JSTOR) of Lodge's article in The North American Review, Vol. 187, No. 630 (May 1908), pp. 724-736, a printed version of his Friday evening discourse at the Royal Institution on 21 February 1908 [read: p.1-2]. Lodge argues that action at a distance is impossible and that a connecting medium, the ether, must exist. He cites Newton's remark that a pressure deficit in a medium near bodies would give gravitation, the wave theory of light (Young), and Faraday and Maxwell for the electric and magnetic roles of the ether. He quotes J. J. Thomson that all mass, momentum and kinetic energy are those of the ether carried along by Faraday tubes. He distinguishes ether from matter: matter moves, the ether is strained and stationary, and all potential energy is in the ether. To explain how a perfect fluid could make solids, he cites Kelvin and examples of 'kinetic elasticity' (rigid spinning cord, water jet, spinning disc, vortex ring). He reports that spinning steel discs a yard across at 4,000 rpm produced no perceptible effect on light passing between them [read: p.9]. He holds that the ether near a charge and a magnetic pole spins with moment of momentum e*m (Thomson), argues by gyroscope analogy and Faraday's magnetic rotation, and presents Current, Magnetism and Motion (E, H, V) as three mutually perpendicular vectors linking electricity, magnetism and mechanics. He then states that inertia could be explained electromagnetically if the ether density is of the order 10^12 g/cm^3, giving elasticity of order 10^33 c.g.s. and an internal whirl speed of the order of the speed of light, and that each cubic millimetre then holds the mass equivalent of a thousand tons and energy equal to a million-horsepower station running for forty million years [read: page image p.10-11]. A 'Supplementary Remarks' section answers a critic: the ether is a perfect plenum of uniform density, matter is an aggregate of electron singularities, and matter is 'millions of times rarer' than ether only in average density. Lodge uses Kelvin's figures (1.5e36 tons in 1.12e59 m^3, about 1e-23 of the density of water) and a 1705 passage from Hooke (found by Poynting). He says his estimate rests on measured electron mass and a calculated electron volume, and that the order of magnitude is independent of the model of electron mass [read: p.14]. He does not show the density calculation here; the footnote on p.7 refers to his Philosophical Magazine paper of April 1907 [read: p.7]. He also raises, tentatively, that the ether may have 'psychical significance' and may be the organism of beings with life and mind (Unseen Universe) [read: p.7-8, p.11]. Digest corrections: the digest gave the telescope parallax as 1/2 arc-second (page image: 1/1000 second of arc), and the p.5 disruption stress as 10^88 dynes/cm^2 (page image, 400 dpi, and the 1909 book App. 1: 10^33 dynes/cm^2) [read: page image p.5]. From p.11 on the digest's page labels run one page late (the Supplementary Remarks begin on PDF p.11). Pages 2-9 detail (deep read, verbatim from text layer): p.2 Lodge, citing Maxwell's lecture 'Action at a Distance', denies action across empty space but says 'I am not denying telepathy' [read: p.2]. p.4 Newton's 'Optical Queries': lower medium pressure near bodies drives them together, and a pressure diminution 'inversely as the distance' gives the law of gravitation [read: p.4]. p.4: the force holding the moon 'would be great enough to tear asunder a steel rod four hundred miles thick, with a tenacity of 30 tons per square inch'; 'Maxwell calculates that the gravitational stress near the earth ... is 3,000 times greater than what the strongest steel could stand; and near the sun it should be 2,500 times as great' [read: pp.4-5]. p.5: if the visible universe (Kelvin: about a thousand million suns) were concentrated in one body, the interior tension 'rose to the value of 10^33 dynes per square centimetre, something would have to happen' (an ethereal disruption); footnote: 'On doing the arithmetic, however, I find the necessary concentration absurdly great, showing that such a mass is quite insufficient' [read: page image p.5]. p.7-8: the Unseen Universe (Balfour Stewart and Tait) and Maxwell's tentative quotation that the ether might be 'the material organism of beings exercising functions of life and mind as high or higher than ours', which Maxwell calls 'far transcending the limits of physical speculation' [read: p.7]. p.8: 'ether is strained ... it may vibrate, and it may rotate, but as regards locomotion it is stationary ... absolutely stationary, so to speak; our standard of rest' [read: p.8]. p.8-9 kinetic-elasticity examples: spoked wheel, silk cord (wave speed equals cord speed), spinning chain, water jet, spinning paper disk (Sir William White: naval steel plates cut by a fast soft-iron disk), vortex ring from an elliptical orifice, Kelvin's spring balance of spinning rigid bodies (Popular Lectures vol.1 p.239, 1884 BA address) [read: pp.8-9]. p.9: 'I have spun steel disks, a yard in diameter, 4,000 times a minute, have sent light round and round between them, and tested carefully for the slightest effect on the ether. Not the slightest effect was perceptible. We cannot spin ether mechanically.' No data are given in the article [read: p.9]. p.9: 'Not speed, but sudden change of speed, is the necessary condition for generating waves in the ether by electricity', illustrated by X-rays from sudden stoppage of a charge [read: p.9]. Density derivation (outside the article): it is printed in Lodge, Phil. Mag. April 1907 (sect. 12) and in the 1909 book 'The Ether of Space' App. 2; the reviewers read it there. It reduces to electromagnetic mass plus an assumed electron radius, with w0 = u [read: reviewers' reads of research/files]; exponents in the 1907 djvu OCR are garbled and were reconstructed from context [read: OCR garbled, reconstructed]. Moon-rod check [computation]: Earth-Moon force 1.98e20 N against a 400-mile-diameter rod at 30 tons/in^2 (about 1.5e20 N) is consistent within about 30%; Maxwell's '3,000 times' and '2,500 times' do not reproduce from g^2/(8 pi G) (about 125 times and about 780 times); Maxwell's own text was not read [computation; memory medium for Maxwell's source]. Disc experiment, primary sources: Lodge's own 1893 Phil. Trans. paper says 'hitherto I have not spun them at more than 3000 revolutions to the minute' (makers 'recommend no speed over 4000'), the disks being two steel circular-saw plates one yard across; the 1893 conclusion already says ('either the ether between the disks is quite unaffected by their motion, or, if affected at all, ... by something less than the thousandth part'), while 'for rigorous proof' he preferred to assert only a larger bound, printed garbled in the 1893 OCR; the 1909 book (ch. V) gives it as 1/200 [read: Phil. Trans. A 184 pp.758, 777-778; read: 1909 book lines 2093-2100 per QE]. The 1897 abstract: disks 'chiefly at 3000 revolutions a minute', also a half-ton iron mass, a magnetised mass and an electrified third disk, all null; Lodge concludes 'no viscous connexion between the ether and matter of observable magnitude, i.e. that whatever motion moving matter may confer upon the ether must be of an irrotational kind. It was demonstrated theoretically in the previous memoir that no optical experiments could be competent to detect motion of this latter character' [read: philtrans08143045.pdf]. So the documented speed is about 3,000 rpm (edge speed about 144 m/s [computation]); 4,000 rpm is the 1908 lecture figure. Positive-charge escape clause (p.14): the only way out of the density estimate would be 'the discovery that the negative electron is not the real or the main matter-unit ... whereas the main mass is the more bulky positive charge', which would 'probably land us in much the same sort of ethereal density' [read: p.14]. Related work: Lodge's 1920 note in Phil. Mag. v.39 (pp.~161-174) comments on Silberstein's Stokes-Planck condensed-ether paper; Silberstein finds an optical index reproducing 'Einstein's formula (quite apart from his theory)', and Lodge writes that the index needed is 1 + 2*gamma*M/(r c^2), the dielectric constant ratio 1 + 4*gamma*M/(r c^2) ('the second term being Einstein's deflexion'), and that an electron might be 'a small region in which intrinsic circulation has ceased' [read: philmag-1920 txt]. For this index the ray deflection is 4GM/(c^2 b), the full Einstein value (1.75 arcsec at the Sun's limb) to first order [computation; QE correction of the mathematician's 'half']; it is an effective, fitted index equivalent to weak-field general relativity, not an independent prediction. Digest-only items also in the article: the Hooke (1705) and Poynting continuum-denser-than-aggregate argument (Lodge says his estimate does not rest on it) and the argument that finite light speed implies finite ether density [read: pp.13-14].

Key claims

• Matter acts on matter only through a continuous medium, the ether; action across truly empty space does not occur.
• All strain, cohesion and potential energy reside in the ether, and the ether itself is absolutely stationary (it strains, vibrates and may rotate, but has no locomotion).
• All mass, momentum and kinetic energy of a body are those of the ether carried along by the Faraday tubes of its atoms (quoted from J. J. Thomson, endorsed by Lodge).
• Matter is made of the ether: an electron is a singularity or strain centre in an ether of perfectly uniform density, not a local rarefaction.
• The ether density is of the order of 10^12 g/cm^3, from the measured electron mass divided by the calculated effective electron volume, and this order of magnitude is the same whether the electron mass is electrostatic, magnetic or hydrodynamic.
• With that density the ether's elasticity is of the order 10^33 c.g.s., and if this is intrinsic turbulence the internal whirl speed is of the order of the velocity of light.
• Each cubic millimetre of ether holds the mass equivalent of about a thousand tons and energy equal to a million-horsepower station running for forty million years.
• Inertia could be explained electromagnetically if the ether density is of the order 10^12 g/cm^3 (stated, not demonstrated in this article; the derivation is in Phil. Mag. April 1907 sect. 12 and the 1909 book App. 2, reducing to electromagnetic mass plus w0 = u and an assumed electron radius).
• The ether near a charge e and a magnetic pole m spins about the line joining them with moment of momentum exactly e*m (J. J. Thomson), and Faraday's magnetic rotation is a gyrostatic action revealing this otherwise unrecognizable spin.
• Current, Magnetism and Motion (E, H, V) are three mutually perpendicular vectors, any two of which imply the third, and this may underlie all physical science and the three dimensions of space.
• Spinning steel discs a yard in diameter at 4,000 rpm (the 1908 figure; the 1893 and 1897 papers document runs chiefly at 3,000 rpm) showed no perceptible effect on light passing between them, so the ether cannot be spun mechanically (Lodge's own negative result, reported without data in 1908; his 1893-1897 papers conclude 'no viscous connexion' and say optical experiments cannot detect irrotational ether motion).
• A fluid in motion can imitate solid rigidity and elasticity (kinetic elasticity), so a fluid ether could constitute solid matter (Kelvin).
• The visible cosmos has an average density of about 1e-23 of water (Kelvin's figures: 1.5e36 tons in 1.12e59 m^3), so matter is far rarer in aggregate than the ether it is made of.
• The ether may have psychical significance, as matter constitutes the brain (speculative aside; Lodge disagrees with anyone who thinks it probably has none).
• If the whole visible universe (Kelvin: about a thousand million suns) were concentrated in one body, the interior gravitational tension might reach 10^33 dynes/cm^2 and cause ethereal disruption; Lodge's footnote says the arithmetic shows the needed concentration 'absurdly great', so the mass is insufficient.
• The only way out of the 10^12 density estimate would be if the main matter-unit were the bulkier positive charge rather than the negative electron, which Lodge says would 'probably' give 'much the same sort of ethereal density' (p.14).
• Gravitation can arise from a diminution of ether pressure (increase of tension) near each electron, falling off inversely as distance (Newton's Optical Queries); the Moon's pull would break a steel rod 400 miles thick, and Maxwell's gravitational stress is stated as 3,000 times (Earth) and 2,500 times (Sun) the strongest steel's strength.
• Not speed but sudden change of speed of an electric charge generates waves in the ether (X-rays from sudden stoppage).
• Lodge denies action at a distance across empty space but does not deny telepathy.

Relevance: This is the only document in the project, and it gives Lodge's late statement of a dense, stationary, perfect-fluid ether from which matter is made. It carries the numerical ether figures (density, elasticity, energy per mm^3) that any review of Lodge's ether work turns on. It also records his own spinning-disc null result and his attributions to Thomson, Kelvin, Faraday, Hooke and Poynting. The derivation of the headline density is cited to the April 1907 Phil. Mag. paper, which is not in the project folder but was downloaded by the Investigator (research/files) and read by the reviewers; the disc-experiment primary reports (Phil. Trans. 1893, 1897) and the 1920 Phil. Mag. exchange were read in the QE remediation.

Mainstream conflict: Mainstream physics since special relativity (1905) and the Michelson-Morley result does not use a material ether as a mechanical medium, and treats the electromagnetic field as having its own degrees of freedom. A stationary ether of density 1e12 g/cm^3 and the claim that all mass is ether mass conflict with that view, and the claim that the ether is both absolutely stationary and a source of inertia raises questions that reviewers must address. Electromagnetic-mass models of the electron have also been superseded. The field angular momentum of a charge-pole pair is a real result in standard electrodynamics (the reviewers confirmed it in Step 2; see arbiter.md). 'Sudden change of speed, not speed, radiates' is correct standard physics (radiation from an accelerated charge). Lodge's 1920 ether refractive index n = 1 + 2GM/(rc^2) reproduces the full first-order Einstein light deflection (an effective description equivalent to weak-field general relativity). Lodge's positive-charge clause points to a matter-unit density near 10^14 g/cm^3 (nuclear-scale, [computation]/[memory high]), a density of matter units, not of empty space. The 1e-23 density figure for the visible cosmos and the Kelvin inputs are checkable astronomical estimates; the density figure is internally consistent, though the solar mass used is about 25% low by the modern value.