5.2.1 Origins of Special Relativity

Or How to Hide Your Sources

If your email server truncates this post, click on the headline to view online.

“It was Ernst Mach who, in his History of Mechanics, shook this dogmatic faith [in classical mechanics],” a 67-year-old Einstein declared. “[T]his book exercised a profound influence upon me in this regard while I was a student,” he continued [[i]], although in his later career, Einstein ultimately rejected much of Mach [[ii], [iii]]. We know that Einstein and his classmates were enthused with Henri Poincaré (1854–1912) [[iv], [v], [vi]]. So, on whose shoulders did Einstein stand in devising and presenting his theory of special relativity? A logical first step would be to review the sources Einstein cites in his paper. Therein lies a problem. Einstein’s friend, physicist Max Born (1882–1970), explains:

Many of you will have looked up his [Einstein’s] paper… and you will have noticed some peculiarities. The striking point is that it contains not a single reference to previous literature. It gives you the impression of quite a new venture. But that is, of course, as I have tried to explain, not true [[vii]].

“The secret of creativity is knowing how to hide your sources,” Einstein allegedly said [[viii]]. While that quote might be apocryphal, Einstein excused not providing a “thoroughly pedantic survey of the literature” in a later paper on the dubious grounds that what he was about to present “had already been partly solved by other authors” [[ix]]. A more generous but still not exculpatory hypothesis was that somehow Einstein was emulating the practice of the patents he was reviewing which tended not to include any references [[x]].

Courtesy, azquotes.com.

Einstein’s 1905 paper appeared not long after that of Lorentz, raising the question of whether Einstein may have plagiarized the Dutch scientist and his famous Lorentz transformations. Physicist and historian, Hans Christoph Ohanian (1941–   ), observes:

…the internal evidence from the papers speaks against plagiarism: Lorentz and Einstein used completely different methodologies, and, besides, their papers contain discordant technical mistakes… Concordance of these mistakes would have been strong evidence of plagiarism; discordance is not strong evidence of anything, but it entitles Einstein to the benefit of doubt [[xi]].

Figure 5.12: Henri Poincaré (1854–1912), seated, explains something to Marie Curie (1867–1934) in a photo taken at the 1911 Solvay Conference in Brussels, Belgium. Atomic physicist, Ernest Rutherford (1871–1937), 1911 Nobel Laureate in Physics for the liquification of helium [NOT for the discovery of superconductivity; see note], Heike Kamerlingh Onnes (1853–1926), and Albert Einstein (1879–1955) stand left-to-right, behind [[xii]]. Poincaré died about nine months after this photo was taken.

On the other hand, Einstein confirmed in his paper the “Lorentz’s theory … is in agreement with the principle of relativity” [[xiii]]. Perhaps the evidence is only circumstantial that Einstein plagiarized relativity, but should we extend the benefit of the doubt to one who has clearly hidden the evidence?

By failing to note his influencers and predecessors, like Poincaré and Hendrik Antoon Lorentz (1853–1928), Einstein created lasting disputes about the extent to which his thinking was original and how much it was derivative. Max Born shared Einstein’s account, decades after the fact, of what Einstein recalled as his influencers [[xiv]], and historians have done extensive detective work to piece together the sources and references on which Einstein may have relied [[xv]]. The point is, they should not have had to do this. Einstein exhibited a shockingly cavalier attitude toward citing references throughout his career.

For instance, concurrently with his work on relativity, Einstein presented a formula for the proportionality of mass (m) and energy (E), with the speed of light squared (c²) as the constant of proportionality. It was mathematically equivalent to what would become the renowned relation: “E = mc²” [[xvi]]. The speed of light squared is a very big number and implies that a little bit of mass may be equivalent to a great deal of energy. This would ultimately have obvious implications for atomic weapons, and nuclear power, as well as the gravitational bending of light.

There was a long road to E = mc², however. English engineer and physicist, Samuel Tolver Preston (1844–1917), proposed matter and energy might be equivalent in his book Physics of Ether in 1875 [[xvii]]. Preston hypothesized that matter divided infinitesimally finely would move at the speed of light, implying a kinetic-energy-derived mass-energy relation equivalent to E = ½ mc². British physicist J.J. Thomson (1856–1940) argued that a moving conductor exhibits an extra mass proportional to its electrostatic energy, suggesting E = ¾ mc² [[xviii]]. Canadian-American astronomer, Simon Newcomb (1835–1909) discussed the relativistic nature of energy in 1889 [[xix]]. In 1900, Poincaré also suggested that electromagnetic energy had a mass associated with it, implying E = mc² [[xx]], and as earlier noted, we have the memoirs of Einstein’s friends who shared that they and Einstein were reading Poincaré. Italian geologist, physicist, and businessman, Olinto De Pretto (1857–1921), proposed E = mc² in 1903 [[xxi]], drawing upon the archaic concept of vis viva [[xxii]]. It has been argued that Einstein’s close friend, “[a] Swiss Italian named Michele Besso (1873–1955) alerted Einstein to the research” [[xxiii]]. Some dispute crediting De Pretto on the grounds that his derivation is mathematically questionable [[xxiv]].

However, Einstein’s own derivation of E = mc² in 1905 was similarly flawed and limited in applicability. Einstein’s result was only valid in the low velocity limit, and he failed to generalize it to all velocities [[xxv]]. Max Planck (1858–1947) correctly called Einstein’s result an “assumption permissible only in the first approximation” [[xxvi]], but Planck’s comment appeared in a footnote that was widely ignored.

Figure 5.13: A 1931 photograph of Nobel Laureates (from left to right), Walther Nernst (1864–1941), Albert Einstein (1879–1955), Max Planck (1858–1947), Robert Andrews Millikan (1868–1953), and Max von Laue (1879–1960), at a 1931 party hosted by von Laue in Berlin [[xxvii]].

Finally, it was German physicist Max von Laue (1879–1960), winner of the 1914 Nobel Prize in Physics for his pioneering work on the diffraction of x-rays [[xxviii]], who offered the first complete and comprehensive proof of E = mc² in 1911 [[xxix]].

There were many milestones along the road to E = mc², and I’ve merely presented a summary of those I thought most important. Who first suggested matter-energy equivalence? Preston in 1875. Or the relativistic nature of energy? Newcomb in 1889. A correctly derived result in a limited case? Poincaré in 1900. The actual formula? De Pretto in 1903. The correct result in a different limited case and arguing it should be generalized outside the context of electromagnetic energy? Einstein in 1905. The correct result rigorously proven to be generally applicable? That was von Laue in 1911. Einstein’s work was an important milestone but it was neither the only one nor the final conclusive one. And Einstein cited none of these predecessors. As Ohanian notes, “Oddly, even today von Laue’s general proof of the E = mc² relation is not widely known, and it is rarely mentioned in physics textbooks, which mostly content themselves with some handwaving arguments about E = mc² and some version of Einstein’s defective proofs” [[xxx]].

A postscript, courtesy of Ohanian [[xxxi]]: in 1912, Einstein adapted von Laue’s proof for an omnibus volume on recent advances in physics. The war delayed publication until 1924. Einstein’s contribution was not included, because he refused the publisher’s request to update it. Einstein reused his submission in a 1914 paper and in his Princeton lectures in 1921, published later that year as The Meaning of Relativity. Nowhere did he acknowledge von Laue. What’s more, Einstein’s paraphrase of von Laue included what Ohanian characterized as “the zaniest mistake in his entire oeuvre, an absolutely nonsensical mistake.”

We have a word for Einstein’s pattern of behavior. That word is “plagiarism.” Christopher Jon Bjerknes (1965–  ) expounds at length upon the misdeeds of “the incorrigible plagiarist” [[xxxii]]. By passing off the work of others as his own and without acknowledgement, Einstein enhanced his own reputation for genius while denigrating the contributions of his colleagues.

This is just the tip of the iceberg, however. Did Einstein write his own papers by himself? Or did he have help? “Oh, that Einstein,” his math professor, Hermann Minkowski (1864–1909) declared, “always cutting lectures — I really would not have believed him capable of it” [[xxxiii]]. Einstein was able to skip class because his good friend, Swiss mathematician Marcel Grossmann (1878–1936), shared his meticulous notes [[xxxiv]]. ‘‘For me it [Einstein’s success] came as a tremendous surprise,” Minkowski explained to his former student Max Born, “for in his student days Einstein had been a lazy dog. He never bothered about mathematics at all” [[xxxv]].

Some speculate Einstein’s fellow student and mathematically inclined wife, Mileva Marić (1875–1948), contributed to his work. “How happy and proud I will be when the two of us together will have brought our work on relative motion to a victorious conclusion,” Einstein wrote Marić in 1901 [[xxxvi]]. “My wife solves all my mathematical problems,” he is reputed to have said [[xxxvii]]. Marić soon became pregnant by him. Einstein refused to marry her. Marić gave birth to their daughter, Liserl, in 1902. Liserl’s fate is unknown, perhaps given up to adoption. Her very existence was unknown until thirty years after Einstein’s death [[xxxviii], [xxxix]].

Figure 5.14: A 1912 photograph of Mileva Einstein-Marić (1875–1948) and Albert Einstein (1879–1955) [[xl]].

Einstein ultimately married Marić in 1903, and they had their first son, Hans Albert, in 1904 [[xli]]. There is much contemporary evidence of the depths of their collaboration during the period when Einstein’s famous papers were written. “If it were not for the cultural imperialism of the U.S. academic establishment, it might be known in Princeton what is known in Novi-Sad – Einstein-Marić was the scientific collaborator of her husband” [[xlii]]. Other critics dispute that she made significant contributions [[xliii], [xliv]]. A recent comprehensive examination concludes she did not significantly contribute [[xlv]]. Either way, the collaboration would not last. The Einsteins’ second son, Eduard, was born in 1910.

In 1912, Einstein began an affair with his first cousin, Elsa. Marić left Einstein in Berlin and returned to Zurich with her two sons in 1914. In 1919, she agreed to a divorce with the stipulation that if Einstein won the Nobel Prize, she would receive the money. Einstein floated the notion of marrying Elsa’s twenty-year-old daughter, Ilse (who spurned her forty-year-old suitor [[xlvi]]), but ultimately, he married Elsa in 1919 after the divorce was final. When Einstein won the 1921 Nobel Prize, he gave Marić only half the winnings he’d promised, and he invested the rest, losing it in the 1929 crash. Marić invested her partial share in an apartment and lived off the modest rent, taking care of Eduard who developed schizophrenia and who eventually required institutionalization [[xlvii]].

Figure 5.15: A 1921 photograph of Albert Einstein (1879–1955) and Elsa Einstein (1876–1936), his first cousin and second wife [[xlviii]].

Einstein’s attitude toward his own disabled son is reflected in the advice he offered his long-time close friend, Austrian physicist Paul Ehrenfest (1880–1933). He advised Ehrenfest to abandon his own Down-syndrome-afflicted son, saying “valuable persons should not be sacrificed to hopeless causes.” Unwilling to do so, yet overwhelmed by the situation, Ehrenfest, recently separated from his wife, shot and killed his son before ending his own life with the same revolver [[xlix], [l]].

Hebrew University of Jerusalem, an institution Einstein co-founded in 1918, zealously guards the popular image of Einstein as sage and savant, as a wise and gentle genius, absent-minded yet approachable. The university has earned an estimated quarter billion dollars from licensing Einstein’s name and image [[li]]. Yet that image is grossly at odds with his actual behavior. Whatever the extent of Einstein’s collaboration and troubled relationship with Mileva Marić, his (their?) work would eventually have a profound impact.

Next time: 5.2.2 The “Annus Mirabilis:” It Was Only 'Mirabilis' With Benefit of Hindsight

Enjoyed the article, but maybe not quite enough to spring for a paid subscription?
Then click on the button below to buy me a coffee. Thanks!

Full Table of Contents [click here]

Follow Online:

You may follow me online in other places as well:

• Telegram: 𝔸𝕖𝕥𝕙𝕖𝕣𝕔𝕫𝕒𝕣'𝕤 𝔸𝕖𝕥𝕙𝕖𝕣𝕤𝕥𝕣𝕖𝕒𝕞

• Gab: @aetherczar

• Twitter: @aetherczar

• Amazon: Hans G. Schantz

• Wise of Heart Substack

• ResearchGate

• Google Scholar

• ORCID

---

References

---

[[i]]         Einstein, Albert, “Autobiographical Note,” collected in Albert Einstein: Philosopher-Scientist, 2^nd ed., Paul Arthur Schlipp, editor, New York: Tudor Publishing Company, 1951, p. 21.

[[ii]]        Isaacson, Walter, Einstein: His Life and Universe, New York: Simon & Schuster, 2007, p. 92. See: https://amzn.to/3UW0fyw

[[iii]]       Berkson, Willaim, Fields of Force: The Development of a World View from Faraday to Einstein, New York: John Wiley & Sons, 1974, pp. 294-295. See: https://amzn.to/4fxTXgC

[[iv]]        Darrigold, Oliver, “The Mystery of the Einstein- Poincaré Connection,” Isis, 95(4), December 2004, pp. 614-626. DOI: 10.1086/430652.

[[v]]        Gingras, Y.. “The Collective Construction of Scientific Memory: The Einstein-Poincare Connection and its Discontents, 1905-2005,” History of Science, vol. 46, no. 1, 2008, pp. 75–114. doi:10.1177/007327530804600103.

[[vi]]        Rothman, Tony, Everything’s Relative: and Other Fables from Science and Technology, New York: John Wiley & Sons, 2003, pp. 73. See: https://amzn.to/4eyEWdm

 “George Sudarshan … insists not only that Einstein must have known about Bachelier’s work [on Brownian motion] but that documentary evidence exists proving that around 1905 Einstein attended a seminar at University of Bern dedicated to Poincaré’s theory of relativity, and that thus Einstein knew about it. If true, this would be an important development in the history of science, and so I put two colleagues at Bern, Hans Bebie and Viktor Gorge, on the hunt. However, after a fairly thorough search, they turned up nothing.”

[[vii]]       Born, Max, Physics in my Generation, London: Pergamon Press, 1956, p. 193. See: https://amzn.to/3YX12Ai

[[viii]]      Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 91. O’Hanian acknowledges that while this is widely attributed to Einstein, “…there seems to be no paper trail for it.” See: https://amzn.to/3Cs5Bek

[[ix]]       Einstein, A., “Über die vom Relativitätspringzip geforderte Trägheit der Energie,” Annalen der Physik, vol. 23, no. 4, 1907, pp. 371-384. Quote on p. 373. “… the nature [of physics is] that what follows has already been partly solved by other authors. I am [therefore] entitled to leave out a thoroughly pedantic survey of the literature…”

[[x]]        Galison, Peter, Einstein’s Clocks, Poincaré’s Maps: Empires of Time, New York: W.W. Norton, & Company, 2004, p. 259. See: https://amzn.to/40RAXFn

“…read Einstein’s contribution through the eyes of the patent world and suddenly the paper looks far less idiosyncratic, at least in style. Patents are precisely characterized by their refusal to lodge themselves among other patents by means of footnotes. If you aim to demonstrate the utter originality of your new machine (and upon originality hinges the patent), you can hardly do worse than shower the inspector with a storm of footnotes to prior work. In the fifty or so Swiss electric clock patents granted in the years around 1905, for example (they are typical), there is not a single footnote either to another patent or to a scientific or technical article.110 This comparison does not prove, of course, why Einstein did not cite others in that first paper. But it may help make sense of why a young patent officer in a hurry may not have felt impelled to situate his work in the matrix of papers by a Lorentz, a Poincaré, an Abraham, or a Cohn. After three years of evaluating hundreds of patents under Haller’s rigorous demands for analysis and presentation, the specificities of patent work had become, for Einstein, a way of life, a form of work, and (as he suggested to Zangger) a precise and austere style of writing.”

[[xi]]       Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 84. See: https://amzn.to/3Cs5Bek

[[xii]]       Cropped from a larger photo of the attendees of the first Solvay Conference in 1911. See: https://upload.wikimedia.org/wikipedia/commons/c/ca/1911_Solvay_conference.jpg

Check any encyclopedia (even books about the Nobel prize) about who discovered it, and you will find it attributed to Heike Kamerlingh Onnes in 1911, a discovery for which he won the coveted award. In fact, Kamerlingh Onnes won the prize for the liquefaction of helium. Judging from reports by those close to the work, there can be no question that it was an assistant, Gilles Holst, who first observed that near absolute zero the element mercury lost all electrical resistance. It is also true that Holst’s name never appeared on the paper. As to the rest—rumors about injured pride, about professional misconduct, and that Kamerlingh Onnes initially disbelieved Holst’s results and had to be persuaded by repeated trials (they all did)—all this seems to be unverifiable.

See: Rothman, Tony, Everything’s Relative: and Other Fables from Science and Technology, New York: John Wiley & Sons, 2003, p. 3.

[[xiii]]      Rothman, Tony, Everything’s Relative: and Other Fables from Science and Technology, New York: John Wiley & Sons, 2003, pp. 72-73. See: https://amzn.to/4eyEWdm

[[xiv]]      Born, Max, Physics in my Generation, London: Pergamon Press, 1956, pp. 193-194. See: https://amzn.to/3YX12Ai

[[xv]]       Miller, Arthur I., Albert Einstein’s Special Theory of Relativity: Emergence (1905) and Early Interpretation (1905-1911), Springer, Paperback, 1997, p. 80-86. See: https://amzn.to/3AN2z3W

[[xvi]]      Einstein, Albert, “Ist die Trägheit eines Körpers von seinem Energieinhalt abhängig?,” (“Does the Inertia of a Body Depend Upon Its Energy Content?”), Annalen der Physik, vol. 18 no. 13, 1905, pp. 639–641.

[[xvii]]      Preston, Samuel Tolver, Physics of the Ether, 1875, p. 115. See: https://archive.org/details/physicsether00presgoog

“165. To give an idea, first, of the enormous intensity of the store of energy attainable by means of that extensive state of subdivision of matter which renders a high normal speed practicable, it may be computed that a quantity of matter representing a total mass of only one grain, and possessing the normal velocity of the ether particles (that of a wave of light), encloses a store of energy represented by upwards of one thousand millions of foot tons, or the mass of one single grain contains an energy not less than that possessed by a mass of forty thousand tons, moving at the speed of a cannon ball (1200 feet per second); or otherwise, a quantity of matter representing a mass of one grain endued with the velocity of the ether particles, encloses an amount of energy which, if entirely utilized, would be competent to project a weight of one hundred thousand tons to a height of nearly two miles (1.9 miles).

“This remarkable result may serve to illustrate well the intense mechanical eflfect derivable from small quantities of matter possessing a high normal velocity, the extremely high value of the effect depending on the fact that energy rises in the rapid ratio of the square of the speed.”

Noting that a grain is 6.48×10⁻⁵ kg, we obtain 5.83×10¹² J from E = mc² and  2.72×10¹² J from E = ½mc² . The energy to lift 100,000 tons 1.9 miles is 2.72×10¹² J. Preston implies E = ½mc² .  

[[xviii]]     Whittaker, Edmund, A History of the Theories of Æther and Electricity, vol. 2, (New Tork: Harper and Brothers, 1960), p. 51. Originally published 1953.

[[xix]]      Newcomb, Simon, “On the Definition of the Terms ‘Energy’ and ‘Work,’” LONDON EDINBURGH AND DUBLIN PHILOSOPHICAL MAGAZINE AND JOURNAL OF SCIENCE, Vol. XXVII; Fifth Series, January-June 1889, pp. 115-117. See: https://books.google.com/books?id=s65JAQAAMAAJ&newbks=1&newbks_redir=0&dq=philosophical%20magazine%201889%20newcomb%20energy%20work&pg=PA115#v=onepage&q&f=false

[[xx]]       Whittaker, Edmund, A History of the Theories of Æther and Electricity, vol. 2, (New Tork: Harper and Brothers, 1960), p. 51. Originally published 1953.

[[xxi]]      De Pretto, Olinto, “Ipotesi dell'etere nella vita dell'universo (Hypothesis of Aether in the Life of the Universe),” Reale Istituto Veneto di Scienze, Lettere ed Arti (The Royal Veneto Institute of Science, Letters and Arts), vol. LXIII (II), 1904, pp. 439–500. (Accepted November 23, 1903 and printed February 27, 1904).

[[xxii]]     Smith, George E., “The Vis Viva Dispute: A Controversy at the Dawn of Dynamics,” Physics Today, vol. 59, Issue 10, October 2006, pp. 31–36. Doi:10.1063/1.2387086

[[xxiii]]     Carroll, Rory, “Einstein’s E=mc² ‘was Italian’s idea,’” The Guardian, November 9, 1999. See: https://www.theguardian.com/world/1999/nov/11/rorycarroll

[[xxiv]]     Valente, Luco, “De Pretto come Albert Einstein? ‘No definitive,’” Italy: Università degli Studi di Bari "Aldo Moro", archived 2006. See: https://archive.is/cIjFZ 

“According to De Pretto, ‘the particles of the ether communicate impulses to the molecule of matter by means of vibratory motions’, an axiom from which his intuition derives that the immense living force contained in the latent state in a kilogram of matter, quantifiable with the formula mv² -where m is the mass and v the speed of vibration of the ether, perhaps equal to the speed of light-, is ‘equivalent to that obtainable from millions and millions of kilograms of coal’. In comment he wrote: ‘This idea will certainly be judged by madmen’.”

[[xxv]]      Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 151. See: https://amzn.to/3Cs5Bek

[[xxvi]]     Planck, M. Ann d. Physik 26, 1, 1908, as quoted by Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 151. See: https://amzn.to/3Cs5Bek

[[xxvii]]    From left to right: W. Nernst, A. Einstein, M. Planck, R.A. Millikan and von Laue at a dinner given by von Laue on 12 November 1931 in Berlin. See: https://en.m.wikipedia.org/wiki/File:Nernst,_Einstein,_Planck,_Millikan,_Laue_in_1931.jpg

[[xxviii]]    Whittaker, Edmund, A History of the Theories of Æther and Electricity, vol. 2, (New Tork: Harper and Brothers, 1960), pp. 18-19. Originally published 1953.

[[xxix]]     Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 149. See: https://amzn.to/3Cs5Bek

[[xxx]]     Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 162. See: https://amzn.to/3Cs5Bek

[[xxxi]]     Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, pp. 162-164. See: https://amzn.to/3Cs5Bek

[[xxxii]]    Bjerknes, Christopher Jon, Albert Einstein the Incorrigible Plagiarist, Downers Grove, IL, XTX, Inc., 2002. A qualified recommendation, because Bjerknes presents the case for plagiarism without presenting any of the potentially exculpatory evidence.

[[xxxiii]]   Miller, Arthur I., Albert Einstein’s Special Theory of Relativity: Emergence (1905) and Early Interpretation (1905-1911), Springer, Paperback, 1997, p. 225. See: https://amzn.to/3AN2z3W

[[xxxiv]]    Miller, Arthur I., Albert Einstein’s Special Theory of Relativity: Emergence (1905) and Early Interpretation (1905-1911), Springer, Paperback, 1997, p. xxviii. See: https://amzn.to/3AN2z3W

[[xxxv]]    Seelig, Carl, Albert Einstein: A Documentary Biography, translated by Mervyn Savill, London: Staple Press Limited, 1956, p. 28.

[[xxxvi]]    Troemel-Ploetz, Senta, “Mileva Einstein-Marić: The Woman Who Did Einstein’s Mathematics,” Women’s Studies Int. Forum, vol. 13, no. 5, 1990, pp. 415–432. Quoting Einstein’s Collected Papers, Vol. 1 1987:282. doi:10.1016/0277-5395(90)90094-E See: https://journals.sagepub.com/doi/epdf/10.1080/03064229008534960

[[xxxvii]]   Troemel-Ploetz, Senta, “Mileva Einstein-Marić: The Woman Who Did Einstein’s Mathematics,” Women’s Studies Int. Forum, vol. 13, no. 5, 1990, pp. 415–432. doi:10.1016/0277-5395(90)90094-E See: https://journals.sagepub.com/doi/epdf/10.1080/03064229008534960

[[xxxviii]]  Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 13. See: https://amzn.to/3Cs5Bek

[[xxxix]]   Zackheim, Michele, Einstein’s Daughter: The Search for Lieserl, New York: Riverhead Books, 1999. See: https://amzn.to/40x8vIH

[[xl]]       See: https://infogalactic.com/info/File:Albert_Einstein_and_his_wife_Mileva_Maric.jpg

[[xli]]       Gagnon, Pauline, “The Forgotten Life of Einstein's First Wife: She was a physicist, too—and there is evidence that she contributed significantly to his groundbreaking science,” Scientific American, December 19, 2016. See: https://archive.is/x9kuf

[[xlii]]      Troemel-Ploetz, Senta, “Mileva Einstein-Marić: The Woman Who Did Einstein’s Mathematics,” Women’s Studies Int. Forum, vol. 13, no. 5, 1990, pp. 415–432. doi:10.1016/0277-5395(90)90094-E See: https://journals.sagepub.com/doi/epdf/10.1080/03064229008534960

[[xliii]]     Walker, Evan Harris, John Stachel, “Did Einstein Espouse his Spouse's Ideas?” Physics Today, vol. 42 no. 2, 1989, pp. 9–13. doi:10.1063/1.2810898

[[xliv]]      Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 86. See: https://amzn.to/3Cs5Bek

[[xlv]]      Esterson, Allen, “The story of Mileva Marić: Did Einstein’s first wife contribute to his scientific work?” Mètode Science Studies Journal, vol. 10, pp. 6-12, 2020. See: https://www.redalyc.org/journal/5117/511767145014/html/

[[xlvi]]      Isaacson, Walter, Einstein: His Life and Universe, New York: Simon & Schuster, 2007, pp. 130-131. See: https://amzn.to/3UW0fyw

[[xlvii]]     Gagnon, Pauline, “The Forgotten Life of Einstein's First Wife: She was a physicist, too—and there is evidence that she contributed significantly to his groundbreaking science,” Scientific American, December 19, 2016. See: https://archive.is/x9kuf

[[xlviii]]    Albert Einstein with his wife Elsa, April 2, 1921. This work is from the George Grantham Bain collection at the Library of Congress. According to the library, there are no known copyright restrictions on the use of this work. Images submitted for copyright by Underwood & Underwood are in the public domain in the United States due to expiration or lack of renewal. See: https://commons.wikimedia.org/wiki/File:Einstein_Albert_Elsa_LOC_32096u.jpg

[[xlix]]     Ohanian, Hans, Einstein’s Mistakes: The Human Failings of Genius, New York: W.W. Norton & Company, 2008, p. 310. See: https://amzn.to/3Cs5Bek

“Ehrenfest's younger son, Vassilji, had Down’s syndrome, and years earlier Einstein had advised Ehrenfest to abandon the boy in an institution, because ‘valuable persons should not be sacrificed to hopeless causes, not even in this case.’ [Fölsing, Albert Einstein, Eine Biographie, p. 758]. But, in contrast to Einstein-who had followed this advice in abandoning his son Tete-Ehrenfest could not let go, and he remained much pained by his son’s condition. In September 1933, he acquired a revolver, picked up the boy at the institution in Amsterdam where he was confined, took him to a nearby park, and shot him through the head. Then he shot himself.”

[[l]]         Isaacson, Walter, Einstein: His Life and Universe, New York: Simon & Schuster, 2007, pp. 211-212. See: https://amzn.to/3UW0fyw

[[li]]        Parkin, Simon, “Who owns Einstein? The battle for the world’s most famous face,” The Guardian, May 17, 2022. See: https://www.theguardian.com/media/2022/may/17/who-owns-einstein-the-battle-for-the-worlds-most-famous-face