Project Gutenberg: 2026-10-04
Site: https://www.gutenberg.org/ebooks/40911. Lodge, The Ether of Space (London: Harper, 1909), plain text.
How found: Google result for Lodge "density of the aether" ... and the archive.org listing "theetherofspace40911gut".
Copy: research/files/lodge-1909-ether-of-space-gutenberg40911.txt (fetched with curl).
What it is
The 1909 book expands the 1908 Royal Institution discourse into ten chapters and three appendices. Several passages of the project document reappear almost word for word: - spinning discs at 4,000 rpm (line about 3083) - the psychical significance passage (lines about 3156-3159) - 1,000 tons per mm³, and a million horse-power for forty million years (lines about 2680-2686) - Kelvin's 1/1000 arc-second parallax (lines about 2452, 4013)
Chapters VI ("Etherial Density") and VII ("Further Explanations concerning the Density and Energy of the Ether") are the long form of claims 2-3.
Findings (Priority 1: the inventor's own work)
- Appendix 2, "Calculations in connexion with Ether Density" [web] (lines 4039-4227). This is a clean, typeset version of the 1907 Phil. Mag. derivation. - Sphere in a perfect liquid: effective mass 2πρa³. - Magnetic circulation: ½ρw² = μH²/8π, with H = eu sinθ / r². - Hence w/u = √(μ/4πρ)·e sinθ/r², energy (4/3)πρa³w₀², and m = (8/3)πρa³(w₀/u)². - Taking w₀ = u gives e = a²√(4πρ/μ), and m = twice the spherical mass. - "the linear dimension of an electron is 10⁻¹³ centimetre diameter, and its mass is of the order 10⁻²⁷ gram. Consequently the density of its material must be of the order 10¹² grams per cubic centimetre." - Lodge: "any reduction in the estimate of the circulation-speed, below that of an electron, would only go to increase it."
This fills the gap noted in claims.md and in the deep read ("Lodge does not show how 10^12 was derived"). The derivation rests on the classical electron size and on the stated assumption w₀ ≈ u. 2. Appendix 1, "On Gravity and Etherial Tension" [web] (lines 3944-4038). - Gravity is an ether "tension" T = γM/r; at the earth's surface it is about 6×10¹¹ c.g.s. - The "critical, or presumably disruptive, stress in the ether" is 10³³ c.g.s., equal to the intrinsic energy density. This resolves the garbled "108S dynes per square centimetre" on p.5 of the project document as 10³³ (to be confirmed from the page image). - Kelvin's 10⁹ suns could not reach it "unless it were concentrated to an absurd degree". A uniform average density of 1.6×10⁻²³ g/cc would reach the disruptive tension at a radius of about 10¹³ light years, and a free-fall speed equal to light at about 10⁷ light years. - The free-fall-equals-c condition is the classical "dark star" condition. That link is not stated by Lodge. 3. Chapter V / whirling machine [web] (lines about 1997-2110). - Lodge quotes his 1893 Phil. Trans. vol.184 p.777 conclusion: velocity of light between plates "not increased or diminished by so much as the 1/200th part of their velocity". - He adds: "since then observations have been continued, and it is now quite safe to change the 1/200th into 1/1000th". - Spin was continued up to three hours. The motor drew up to nine horse-power. Figures 11-13 show photographs of the machine. - This gives a quantitative bound for the spinning-disc result (claim 5) that the 1908 article reports without numbers. 4. Longitudinal magnetic drift [web] (lines about 2280-2310). - The negative result is summarised and referred to Phil. Mag. April 1907 pp.495-500. - Discrepancy to note: the book gives the bound as "1/9th of a millimetre per second, or 16 miles per hour, for each C.G.S. unit". The 1907 paper says "16 inches an hour". 1/9 mm/s is about 0.4 m/h, about 16 inches an hour [computation], so "miles" in the book is apparently a slip.
Bearing on claims
- Claims 2-3: the derivation, with its assumptions, is now available.
- Claim 5: a quantitative bound of 1/1000 of the disc speed.
- Claim 6 and p.5 of the project document: the disruptive-stress threshold.