2026-10-08 Other sites visited (single checks)
ADS (NASA Astrophysics Data System), 1927 Mount Wilson conference: partial
URL: https://articles.adsabs.harvard.edu/full/1928ApJ....68..341M redirects to https://ui.adsabs.harvard.edu/scan/manifest/1928ApJ....68..341M (Scan Explorer). The page images load in an image viewer with no text layer reachable from the page tools, and the scripted fetch returned an empty file. Lorentz's remarks (ApJ 68, pp.345-351 per Wikipedia) were not read. Next run: read the page images for pp.345-351 (Scan Explorer page navigation), or the IOP free-access copy, doi 10.1086/143148.
PubMed Central: Bischoff van Heemskerck (2023/2024), related work (priority 3)
D. Bischoff van Heemskerck, "A Lorentz variant theory that passes fundamental tests of special relativity and makes diverging, testable but as of yet untested predictions", F1000Research 12:407 (version 2, "peer review: 2 approved"), doi 10.12688/f1000research.129133.2, PMC11318248 [web] https://pmc.ncbi.nlm.nih.gov/articles/PMC11318248/. Abstract (quoted): "A variant theory is outlined where relativistic effects such as length contraction and time dilation are purely local consequences of the relative velocity between a system and its medium." "...although this alteration does not align with the principle of relativity, it quantitatively aligns with the experimental results of the fundamental tests of special relativity and their modern variations, and makes diverging, testable but as of yet untested predictions concerning Doppler shift and time dilation." "A modified Ives-Stilwell experiment is proposed to test between this model and special relativity." Bearing: this is a modern descendant of Lorentz's physical (medium-caused) contraction and dilation (claims 2 and 5). Unlike Lorentz in §§192-193 and in 1913, it gives up full reciprocity and proposes a test.
PhilSci-Archive: J. Potters (2023), history of the electron-mass experiments (priority 4)
J. Potters, "Hazy Spots on Photographic Plates: On the Measurement of the Velocity-Dependency of the Electron's Mass", Historical Studies in the Natural Sciences 53(1) (2023) 1-34; preprint https://philsci-archive.pitt.edu/22988/ (PDF 479 kB, not downloaded) [web]. Abstract: it covers the experiments of Kaufmann, Bucherer, Neumann, and Guye with Lavanchy, 1901-1916, all recorded on photographic plates. It distinguishes "two different approaches to the production of precise photographic plates": precision through qualitative plates versus precision through quantity. It argues that these were shaped by the radiating materials at hand and by the intellectual context. Bearing: claim 3, i.e. what the plates Lorentz relied on (Kaufmann 1906, then Bucherer 1908 and the others) could show.
Einstein Papers Project (Princeton): partial
https://einsteinpapers.press.princeton.edu/vol2-doc/308 redirected to the database landing page; no document text was reached. CPAE vol. 2 docs 306 and 308 (Einstein 1907, the review that discusses Kaufmann) and vol. 8 docs 129 and 177 (Einstein-Lorentz 1915-1916) remain to be read.
AMS Bulletin: E. B. Wilson's 1917 review of the 2nd edition: partial
https://www.ams.org/journals/bull/1917-24-02/S0002-9904-1917-03025-X (landing page; "The AMS does not provide abstracts of book reviews"). The free PDF did not come through a scripted fetch (HTML returned) and was not opened in Chrome. Next run: open the PDF in Chrome. It is a contemporary reading of the 1916 edition by a mathematical physicist (E. B. Wilson, who also wrote with G. N. Lewis on relativity [memory, medium]).
UvA-DARE: A. J. Kox, chapter on the 1909 edition
A. J. Kox, "H.A. Lorentz, Lectures on electron theory, First edition (1909)", in I. Grattan-Guinness (ed.), Landmark Writings in Western Mathematics 1640-1940 (Amsterdam: Elsevier 2005), pp.778-783 [web] https://dare.uva.nl/id/5e78aafb-f04e-44b2-980d-cd9aa34ff281. Record only; no full text on the page. This is a scholarly history of this very book by the editor of Lorentz's correspondence.
KNAW Digital Library (DWC)
Lorentz, "Electromagnetic phenomena in a system moving with any velocity smaller than that of light", Proc. KNAW 6 (1904): https://dwc.knaw.nl/DL/publications/PU00014148.pdf. Reachable (HTTP 200, 982,745 bytes); not downloaded. This is the 1904 original of Chapter V §§169-178, so l and the deformable electron can be compared between the paper and the lectures.
GBV (Gemeinsamer Bibliotheksverbund) table of contents: negative
https://www.gbv.de/dms/tib-ub-hannover/1029674280.pdf (Kox vol. 2 TOC) lists only the front matter (Introduction, Biographical sketch, List of Letters, Letters 1-814, Bibliography, Index).
Wikisource
Einstein, "Ether and the Theory of Relativity" (1920): quoted in 2026-10-08-wikipedia.md.