Relativity priority dispute
presented the theories of special relativity and general relativity in publications that either contained no formal references to previous literature, or referred only to a small number of his predecessors for fundamental results on which he based his theories, most notably to the work of Hendrik Lorentz for special relativity, and to the work of Carl F. Gauss, Bernhard Riemann, and Ernst Mach for general relativity. Subsequently, claims have been put forward about both theories, asserting that they were formulated, either wholly or in part, by others before Einstein. At issue is the extent to which Einstein and various other individuals should be credited for the formulation of these theories, based on priority considerations.
The general history of the development of these theories, including the contributions made by many other scientists, is found at History of special relativity and History of general relativity.
The candidates for credit
Concerning special relativity, the most important names that are mentioned in discussions about the distribution of credit are Albert Einstein, Hendrik Lorentz, Henri Poincaré, and Hermann Minkowski. Consideration is also given to numerous other scientists for either anticipations of some aspects of the theory, or else for contributions to the development or elaboration of the theory. These include Woldemar Voigt, August Föppl, Joseph Larmor, Emil Cohn, Friedrich Hasenöhrl, Max Planck, Max von Laue, Gilbert Newton Lewis and Richard Chase Tolman, and others. In addition, polemics exist about alleged contributions of others such as Olinto De Pretto who according to some mathematical scholars did not create relativity but was the first to use the equation; Also Einstein's first wife Mileva Marić, although her contribution is not considered to have any foundation according to serious scholars.Concerning general relativity, there is a controversy about the amount of credit that should go to Einstein, Marcel Grossmann, and David Hilbert. Many others contributed to the development of the mathematical tools and geometrical ideas underlying the theory of gravity. Also polemics exist about alleged contributions of others such as Paul Gerber.
Undisputed and well-known facts
The following facts are well established and referrable:Special relativity
- In 1889,, Henri Poincaré argued that the ether might be unobservable, in which case the existence of the ether is a metaphysical question, and he suggested that some day the ether concept would be thrown aside as useless. However, in the same book he considered the ether a "convenient hypothesis" and continued to use the concept also in later books in 1908 and 1912.
- In 1895, Poincaré argued that results like those obtained by Michelson and Morley show that it seems to be impossible to detect the absolute motion of matter or the relative motion of matter in relation to the ether. In 1900 he called this the Principle of Relative Motion, i.e., that the laws of movement should be the same in all inertial frames. Alternative terms used by Poincaré were "relativity of space" and "principle of relativity". In 1904 he expanded that principle by saying: "The principle of relativity, according to which the laws of physical phenomena must be the same for a stationary observer as for one carried along in a uniform motion of translation, so that we have no means, and can have none, of determining whether or not we are being carried along in such a motion." However, he also stated that we do not know if this principle will turn out to be true, but that it is interesting to determine what the principle implies.
- In, Poincaré published a paper in which he said that radiation could be considered as a fictitious fluid with an equivalent mass of. He derived this interpretation from Lorentz's 'theory of electrons' which incorporated Maxwell's radiation pressure.
- Poincaré had described a synchronization procedure for clocks at rest relative to each other in and again in . So two events, which are simultaneous in one frame of reference, are not simultaneous in another frame. It is very similar to the one later proposed by Einstein. However, Poincaré distinguished between "local" or "apparent" time of moving clocks, and the "true" time of resting clocks in the ether. In he argued that "some day, no doubt, the ether will be thrown aside as useless".
- Lorentz' paper containing the transformations bearing his name appeared in 1904.
- Albert Einstein in derived the Lorentz equations by using the principle of constancy of velocity of light and the relativity principle. He was the first to argue that those principles are sufficient to derive the theory. See Postulates of special relativity. He said: "The introduction of a luminiferous ether will prove to be superfluous inasmuch as the view here to be developed will not require an absolutely stationary space provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place." * Einstein's Elektrodynamik paper contains no formal references to other literature. It does mention, in §9, part II, that the results of the paper are in agreement with Lorentz's electrodynamics. Poincaré is not mentioned in this paper, although he is cited formally in a paper on special relativity written by Einstein the following year.
- In 1905 Einstein was the first to suggest that when a material body lost energy of amount, its mass decreased by the amount.
- Hermann Minkowski showed in 1907 that the theory of special relativity could be elegantly described using a four-dimensional spacetime, which combines the dimension of time with the three dimensions of space.
- Einstein in 1920 returned to a concept of aether having no state of motion.
General relativity
- The proposal to describe gravity by means of a pseudo-Riemannian metric was first made by Einstein and Grossmann in the so-called Entwurf theory published 1913. Grossmann identified the contracted Riemann tensor as the key for the solution of the problem posed by Einstein. This was followed by several attempts of Einstein to find valid field equations for this theory of gravity.
- David Hilbert invited Einstein to the University of Göttingen for a week to give six 2-hour lectures on general relativity, which he did in June–July 1915. Einstein stayed at Hilbert's house during this visit. Hilbert started working on a combined theory of gravity and electromagnetism, and Einstein and Hilbert exchanged correspondence until November 1915. Einstein gave four lectures on his theory on Nov 4, Nov 11, Nov 18 and Nov 25 in Berlin, published as , , , .
- November 4, Einstein published non-covariant field equations and on November 11 returned to the field equations of the "Entwurf" papers, which he now made covariant by the assumption that the trace of the energy-momentum tensor was zero, as it was for electromagnetism.
- Einstein sent Hilbert proofs of his papers of Nov 4 and Nov 11.
- Nov 15 Invitation issued for Nov 20 meeting at the Academy in Göttingen. "Hilbert legt vor in die Nachrichten: Grundgleichungen der Physik".
- Nov 16 Hilbert spoke at the Göttingen Mathematical Society "Grundgleichungen der Physik". Talk not published.
- Nov 16 or Nov 17 Hilbert sent Einstein some information about his talk of Nov 16
- Nov 18 Einstein replies to Hilbert's letter saying as far as he could tell Hilbert's system was equivalent to the one he had found in the preceding weeks.. Einstein also told Hilbert in this letter that he had "considered the only possible generally covariant field equations three years earlier", adding that "The difficulty was not to find generally covariant equations for the ;this is easy with the help of the Riemann tensor. What was difficult instead was to recognize that these equations form a generalization, and that is, a simple and natural generalization of Newton's law". Einstein also told Hilbert in that letter that he had calculated the correct perihelion advance for Mercury, using covariant field equations based on the assumption that the trace of the energy momentum tensor vanished as it did for electromagnetism.
- Nov 18 Einstein presents the calculation of the perihelion advance to Prussian Academy.
- Nov 20 Hilbert lectured to the Göttingen Academy. The proofs of his paper show that Hilbert proposed a non-covariant set of equations as the fundamental equations of physics. Thus he wrote "in order to keep the deterministic characteristic of the fundamental equations of physics four further non-covariant equations... unavoidable.". Hilbert then derives these four extra equations and continues "these four differential equations supplement the gravitational equations to yield a system of 14 equations for the 14 potentials : the system of fundamental equations of physics"..
- In his last lecture on Nov 25 Einstein submitted the correct field equations. The published paper appeared on December 2, and it did not mention Hilbert.
- Hilbert's paper took considerably longer to appear. He had galley proofs that were marked "December 6" by the printer in December 1915. Most of the galley proofs have been preserved, but about a quarter of a page is missing. The extant part of the proofs contains Hilbert's action from which the field equations can be obtained by taking a variational derivative, and using the contracted Bianchi identity derived in theorem III of Hilbert's paper, though this was not done in the extant proofs.
- Hilbert rewrote his paper for publication, changing the treatment of the energy theorem, dropping a non-covariant gauge condition on the coordinates to produce a covariant theory, and adding a new credit to Einstein for introducing the gravitational potentials into the theory of gravity. In the final paper he said his differential equations seemed to agree with the "magnificent theory of general relativity established by Einstein in his later papers"
- The events of late November through December 1915 caused bad feelings from Einstein towards Hilbert. In a November 25 letter to Zangger, Einstein accused Hilbert of attempts to appropriate his theory. On Dec 4, Hilbert nominated Einstein for election as a corresponding member of the Göttingen Mathematical Society. In a December 20 letter to Hilbert, Einstein proposed to settle the dispute.
- The 1916 paper was rewritten and republished in 1924 , where Hilbert wrote: Einstein kehrt schließlich in seinen letzten Publikationen geradewegs zu den Gleichungen meiner Theorie zurück.
Disputed claims
Special relativity
- To what degree Einstein was familiar with Poincaré's work
- * It is known that Einstein was familiar with , but it is not known to what extent he was familiar with other work of Poincaré in 1905. However it is known that he knew in 1906, because he quoted it in .
- Lorentz' paper containing the transformations bearing his name appeared in 1904. The question is whether Einstein was familiar in 1905 with either this paper itself or a review of it.
- To what degree Einstein was following other physicists' work at the time. Some authors claim that Einstein worked in relative isolation and with restricted access to the physics literature in 1905. Others, however, disagree; a personal friend of Einstein, Maurice Solovine, later acknowledged that he and Einstein both pored for weeks over Poincaré's 1902 book, keeping them "breathless for weeks on end" .
- Whether his wife, Mileva Marić, may have contributed to Einstein's work, although Einstein scholars say that there is no substantive evidence that she made significant contributions.
General relativity
- Before 1997, "the commonly accepted view was that David Hilbert completed the general theory of relativity at least 5 days before Albert Einstein submitted his conclusive paper on this theory on 25 November 1915. Hilbert's article, bearing the date of submission 20 November 1915 but published only on 31 March 1916, presents a generally covariant theory of gravitation, including field equations essentially equivalent to those in Einstein's paper". Since the discovery of printer's proofs of Hilbert's paper of Nov 20, dated 6 Dec 1915, which show a number of differences from the finally published paper, this 'commonly accepted view' has been challenged.
- Whether Einstein got the correct mathematical formulation for general relativity from Hilbert, or formulated it independently. Points at issue:
- * The content of Hilbert's November 16 letter/postcard to Einstein is not known. It is however, clear from Einstein's response that it was an account of Hilbert's work.
- * It is not known what was on the missing part of Hilbert's printer proofs. The missing portion is large enough to have contained the field equations in an explicit form. There are several competing speculations about the content of the missing piece.
- * Based on the above, it is not known whether Hilbert had formulated the field equations in an explicit form before December 6 or not.
- * It is known from the proofs that Hilbert introduced four non-covariant equations in order to specify the gravitational potentials and that this approach was dropped from his revised paper.
- Whether Hilbert ever tried to claim priority for the field equations - it seems clear that he regarded the theory of general relativity as Einstein's theory.
- What Hilbert thought he was referring to when he used the term "equations of my theory" about Einstein's research. Hilbert made a similar remark in a letter to Karl Schwarzschild.
Special relativity
Historians of special relativity
In his History of the theories of ether and electricity from 1953, E. T. Whittaker claimed that relativity is the creation of Lorentz and Poincaré and attributed to Einstein's papers only little importance. However, most historians of science, like Gerald Holton, Arthur I. Miller, Abraham Pais, John Stachel, or Olivier Darrigol have other points of view. They admit that Lorentz and Poincaré developed the mathematics of special relativity, and many scientists originally spoke about the "Lorentz-Einstein theory". But they argue that it was Einstein who completely eliminated the classical ether and demonstrated the relativity of space and time. They also argue that Poincaré demonstrated the relativity of space and time only in his philosophical writings, but in his physical papers he maintained the ether as a privileged frame of reference that is perfectly undetectable, and continued to distinguish between "real" lengths and times measured by observers at rest within the aether, and "apparent" lengths and times measured by observers in motion within the aether. Darrigol summarizes:
Most of the components of Einstein's paper appeared in others' anterior works on the electrodynamics of moving bodies. Poincaré and Alfred Bucherer had the relativity principle. Lorentz and Larmor had most of the Lorentz transformations, Poincaré had them all. Cohn and Bucherer rejected the ether. Poincaré, Cohn, and Abraham had a physical interpretation of Lorentz's local time. Larmor and Cohn alluded to the dilation of time. Lorentz and Poincaré had the relativistic dynamics of the electron. None of these authors, however, dared to reform the concepts of space and time. None of them imagined a new kinematics based on two postulates. None of them derived the Lorentz transformations on this basis. None of them fully understood the physical implications of these transformations. It all was Einstein's unique feat.
Comments by Lorentz, Poincaré, and Einstein
Lorentz
In a paper that was written in 1914 and published in 1921, Lorentz expressed appreciation for Poincaré's Palermo paper on relativity. Lorentz stated:However, a 1916 reprint of his main work "The theory of electrons" contains notes in which Lorentz sketched the differences between his results and that of Einstein as follows:
Regarding the fact, that in this book Lorentz only mentioned Einstein and not Poincaré in connection with a) the synchronisation by light signals, b) the reciprocity of the Lorentz transformation, and c) the relativistic transformation law for charge density, Janssen comments:
And at a conference on the Michelson–Morley experiment in 1927 at which Lorentz and Michelson were present, Michelson suggested that Lorentz was the initiator of the theory of relativity. Lorentz then replied:
Poincaré
Poincaré attributed the development of the new mechanics almost entirely to Lorentz. He only mentioned Einstein in connection with the photoelectric effect, but not in connection with special relativity. For example, in 1912 Poincaré raises the question whether "the mechanics of Lorentz" will still exist after the development of the quantum theory. He wrote:Einstein
It is now known that Einstein was well aware of the scientific research of his time. The well known historian of science, Jürgen Renn, Director of the Max Planck Institute for the History of Science wrote on Einstein's contributions to the Annalen der Physik:Einstein wrote in 1907 that one needed only to realize that an auxiliary quantity that was introduced by Lorentz and that he called "local time" can simply be defined as "time." In 1909 and 1912
Einstein explained:
But Einstein and his supporters took the position that this "light postulate" together with the principle of relativity renders the ether superfluous and leads directly to Einstein's version of relativity. It is also known that Einstein had been reading and studying Poincaré's 1902-book Science and hypothesis well before 1905, which included:
- detailed philosophical assessments on the relativity of space, time, and simultaneity
- discussion of the reliance on conventions regarding the use of light signals for the synchronization of clocks
- the definition of the principle of relativity and the conjecture that a violation of that principle can never be detected empirically
- the possible redundancy of the ether hypothesis
- detailed remarks on the physical status of non-Euclidean geometry.
General relativity
Did Hilbert claim priority for parts of General Relativity?
concludes, in remarks based on Hilbert's 1924 paper, that Hilbert regarded the General Theory of relativity as Einstein's: "Quite naturally, and in accord with Hilbert's view of things, the resulting law of warpage was quickly given the name the Einstein field equation rather than being named after Hilbert. Hilbert had carried out the last few mathematical steps to its discovery independently and almost simultaneously with Einstein, but Einstein was responsible for essentially everything that preceded those steps...". However, Kip Thorne also stated, "Remarkably, Einstein was not the first to discover the correct form of the law of warpage Recognition for the first discovery must go to Hilbert."Arguments have been made that Hilbert claimed priority for the field equations themselves; the sources cited for this are:
- Hilbert's article, when it appeared in 1916, contained the text "Die so zu Stande kommenden Differentialgleichungen der Gravitation sind, wie mir scheint, mit der von Einstein in seinen späteren Abhandlungen aufgestellten großzügigen Theorie der allgemeinen Relativität in gutem Einklang." In translation, "The differential equations of gravity arrived at in this way are, I think, in good agreement with those of Einstein in his later papers in which he presented his comprehensive theory of general relativity." Hilbert refers here to the "later papers" of Einstein, obviously to distinguish them from the Entwurf theory of 1913 and the preliminary papers prior to the end of November 1915 when Einstein published the equations of general relativity in their final form.
- Wuensch points out that Hilbert refers to the field equations of gravity as "meine Theorie" in his February 6, 1916 letter to Schwarzschild. This, however, is not at issue, since no one disputes that Hilbert had his own "theory", which Einstein criticized as naive and overly ambitious. Hilbert's theory was based on the work of Mie combined with Einstein's principle of general covariance, but applied to matter and electromagnetism as well as gravity.
- Mehra and Bjerknes point out that Hilbert's 1924 version of the article contained the sentence "... und andererseits auch Einstein, obwohl wiederholt von abweichenden und unter sich verschiedenen Ansätzen ausgehend, kehrt schließlich in seinen letzten Publikationen geradenwegs zu den Gleichungen meiner Theorie zurück" - "Einstein in his last publications ultimately returns directly to the equations of my theory.". These statements of course do not have any particular bearing on the matter at issue. No one disputes that Hilbert has "his" theory, which was a very ambitious attempt to combine gravity with a theory of matter and electromagnetism along the lines of Mie's theory, and that his equations for gravitation agreed with those that Einstein presented beginning in his, Einstein's, Nov 25 paper. None of this bears on the precise origin of the trace term in the Einstein field equations.
- Sauer says "the independence of Einstein's discovery was never a point of dispute between Einstein and Hilbert... Hilbert claimed priority for the introduction of the Riemann scalar into the action principle and the derivation of the field equations from it, " "and Einstein admitted publicly that Hilbert had succeeded in giving the equations of general relativity a particularly lucid form by deriving them from a single variational principle". Sauer also stated, "And in a draft of a letter to Weyl, dated 22 April 1918, written after he had read the proofs of the first edition of Weyl's 'Raum-Zeit-Materie' Hilbert also objected to being slighted in Weyl's exposition. In this letter again 'in particular the use of the Riemannian curvature in the Hamiltonian integral' was claimed as one of his original contributions. SUB Cod. Ms. Hilbert 457/17."
- Einstein wrote to Hilbert on 20 December 1915 that there was an "ill-feeling between us" and it has been suspected that this ill feeling was the result of Einstein's bitterness over Hilbert's "nostrification" of his theory. Others have suggested that Hilbert might have felt that Einstein had derived some benefit or hints from his letters, and that those had helped him to arrive at the trace term of the field equations, and if so, that Einstein should have acknowledged this in his paper. But this is pure speculation, aside from Einstein's comment that he believed others had tried to "nostrify" his theory.
Did Einstein develop the field equations independently?
For a long time, it was believed that Einstein and Hilbert found the field equations of gravity independently. While Hilbert's paper was submitted somewhat earlier than Einstein's, it only appeared in 1916, after Einstein's field equations paper had appeared in print. For this reason there was no good reason to suspect plagiarism on either side. In 1978, a November 18, 1915 letter from Einstein to Hilbert resurfaced, in which Einstein thanked Hilbert for sending an explanation of Hilbert's work. This was not unexpected to most scholars, who were well aware of the correspondence between Hilbert and Einstein that November, and who continued to hold the view expressed by Albrecht Fölsing in his Einstein biography:In the very next sentence, after asking the rhetorical question, Folsing answers it with "This is not really probable...", and then goes on to explain in detail why
In their 1997 Science paper, Corry, Renn and Stachel quote the above passage and comment that "the arguments by which Einstein is exculpated are rather weak, turning on his slowness in fully grasping Hilbert's mathematics", and so they attempted to find more definitive evidence of the relationship between the work of Hilbert and Einstein, basing their work largely on a recently discovered pre-print of Hilbert's paper. A discussion of the controversy around this paper is given below.
Those who contend that Einstein's paper was motivated by the information obtained from Hilbert have referred to the following sources:
- The correspondence between Hilbert and Einstein mentioned above. More recently, it became known that Einstein was also given notes of Hilbert's November 16 talk about his theory.
- Einstein's November 18 paper on the perihelion motion of Mercury, which still refers to the incomplete field equations of November 4 and 11. Reference to the final form of the equations appears only in a footnote added to the paper, indicating that Einstein had not known the final form of the equations on November 18. This is not controversial, and is consistent with the well-known fact that Einstein did not complete the field equations until November 25.
- Letters of Hilbert, Einstein, and other scientists may be used in attempts to make guesses about the content of Hilbert's letter to Einstein, which is not preserved, or of Hilbert's lecture in Göttingen on November 16.
- Hilbert modified his paper in December 1915, and the November 18 version sent to Einstein did not contain the final form of the field equations. The extant part of the printer proofs does not have the explicit field equations. This is the point of view defended by Corry, Renn, Stachel, and Sauer.
- Sauer and Todorov agree with Corry, Renn and Satchel that Hilbert's proofs show that Hilbert had originally presented a non-covariant theory, which was dropped from the revised paper. Corry et al. quote from the proofs: "Since our mathematical theorem... can provide only ten essentially independent equations for the 14 potentials and further, maintaining general covariance makes quite impossible more than ten essential independent equations then, in order to keep the deterministic characteristic of the fundamental equations of physics four further non-covariant equations... unavoidable." Hilbert derives these four extra equations and continues "these four differential equations supplement the gravitational equations to yield a system of 14 equations for the 14 potentials, : the system of fundamental equations of physics".. Hilbert's first theory was titled "The fundamental equations of Physics". In proposing non-covariant fundamental equations, based on the Ricci tensor but restricted in this way, Hilbert was following the causality requirement that Einstein and Grossmann had introduced in the Entwurf papers of 1913.
- One may attempt to reconstruct the way in which Einstein may have arrived at the field equations independently. This is, for instance, done in the paper of Logunov, Mestvirishvili and Petrov quoted below. Renn and Sauer investigate the notebook used by Einstein in 1912 and claim he was close to the correct theory at that time.
Attackers and defenders
Special relativity
Sir Edmund Whittaker (1954)
In 1954, Sir Edmund Taylor Whittaker, an English mathematician and historian of science, credited Poincaré with the equation, and he included a chapter entitled The Relativity Theory of Poincaré and Lorentz in his book A History of the Theories of Aether and Electricity. He credited Poincaré and Lorentz, and especially alluded to Lorentz's 1904 paper, Poincaré's St. Louis speech of September 1904, and Poincaré's June 1905 paper. Whittaker attributed to Einstein's relativity paper only little importance, i.e., the formulation of the Doppler and aberration formulas. Max Born spent three years trying to dissuade Whittaker, but Whittaker insisted that everything of importance had already been said by Poincaré, and that Lorentz quite plainly had the physical interpretation.Gerald Holton (1960)
Whittaker's claims were criticized by Gerald Holton. He argued that there are fundamental differences between the theories of Einstein on one hand, and Poincaré and Lorentz on the other hand. Einstein radically reformulated the concepts of space and time, and by that removed "absolute space" and thus the stationary luminiferous aether from physics. On the other hand, Holton argued that Poincaré and Lorentz still adhered to the stationary aether concept, and tried only to modify Newtonian dynamics, not to replace it. Holton argued, that "Poincaré's silence" was due to their fundamentally different conceptual viewpoints. Einstein's views on space and time and the abandonment of the aether were, according to Holton, not acceptable to Poincaré, therefore the latter only referred to Lorentz as the creator of the "new mechanics". Holton also pointed out that although Poincaré's 1904 St. Louis speech was "acute and penetrating" and contained a "principle of relativity" that is confirmed by experience and needs new development, it did not "enunciate a new relativity principle". He also alluded to mistakes of Whittaker, like predating Lorentz's 1904 paper to 1903.Views similar to Holton's were later expressed by his former student, Stanley Goldberg.
G. H. Keswani (1965)
In a 1965 series of articles tracing the history of relativity, Keswani claimed that Poincaré and Lorentz should have the main credit for special relativity - claiming that Poincaré pointedly credited Lorentz multiple times, while Lorentz credited Poincaré and Einstein, refusing to take credit for himself. He also downplayed the theory of general relativity, saying "Einstein's general theory of relativity is only a theory of gravitation and of modifications in the laws of physics in gravitational fields". This would leave the special theory of relativity as the unique theory of relativity. Keswani cited also Vladimir Fock for this same opinion.This series of articles prompted responses, among others from Herbert Dingle and Karl Popper.
Dingle said, among other things, ".. the 'principle of relativity' had various meanings, and the theories associated with it were quite distinct; they were not different forms of the same theory. Each of the three protagonists.... was very well aware of the others.... but each preferred his own views"
Karl Popper says "Though Einstein appears to have known Poincaré's Science and Hypothesis prior to 1905, there is no theory like Einstein's in this great book."
Keswani did not accept the criticism, and replied in two letters also published in the same journal.
Arthur I. Miller (1973)
agreed with the analysis of Holton and Goldberg, and further argued that although the terminology used by Poincaré and Einstein were very similar, their content differs sharply. According to Miller, Poincaré used this principle to complete the aether based "electromagnetic world-view" of Lorentz and Abraham. He also argued that Poincaré distinguished between "ideal" and "real" systems and electrons. That is, Lorentz's and Poincaré's usage of reference frames lacks an unambiguous physical interpretation, because in many cases they are only mathematical tools, while in Einstein's theory the processes in inertial frames are not only mathematically, but also physically equivalent. Miller wrote in 1981:Miller argues that Poincaré was guided by empiricism, and was willing to admit that experiments might prove relativity wrong, and so Einstein is more deserving of credit, even though he might have been substantially influenced by Poincaré's papers. Miller also argues that "Emphasis on conventionalism... led Poincaré and Lorentz to continue to believe in the mathematical and observational equivalence of special relativity and Lorentz's electron theory. This is incorrect." Instead, Miller claims that the theories are mathematically equivalent but not physically equivalent.
Abraham Pais (1982)
In his Einstein biography Subtle is the Lord, Abraham Pais argued that Poincaré "comes near" to discovering special relativity, but eventually he failed, because in 1904 and also later in 1909, Poincaré treated length contraction as a third independent hypothesis besides the relativity principle and the constancy of the speed of light. According to Pais, Poincaré thus never understood special relativity, in which the whole theory including length contraction can simply be derived from two postulates. Consequently, he sharply criticized Whittaker's chapter on the "Relativity theory of Poincaré and Lorentz", saying "how well the author's lack of physical insight matches his ignorance of the literature", although Pais admitted that the first book of Whittaker's History of Aether and Electricity is a masterpiece.He also argued that Lorentz never abandoned the stationary aether concept, either before or after 1905:
Elie Zahar (1983)
In several papers, Elie Zahar argued that both Einstein and Poincaré independently discovered special relativity. He said that "though Whittaker was unjust towards Einstein, his positive account of Poincaré's actual achievement contains much more than a simple grain of truth". According to him, it was Poincaré's unsystematic and sometimes erroneous statements regarding his philosophical papers, which hindered many to give him due credit. In his opinion, Poincaré was rather a "structural realist" and from that he concludes, that Poincaré actually adhered to the relativity of time and space, while his allusions to the aether are of secondary importance. He continues, that due to his treatment of gravitation and four-dimensional space, Poincaré's 1905/6-paper was superior to Einstein's 1905-paper. Yet Zahar gives also credit to Einstein, who introduced Mass–Energy equivalence, and also transcended special relativity by taking a path leading to the development of general relativity.John Stachel (1995)
argued that there is a debate over the respective contributions of Lorentz, Poincaré and Einstein to relativity. These questions depend on the definition of relativity, and Stachel argued that kinematics and the new view of space and time is the core of special relativity, and dynamical theories must be formulated in accordance with this scheme. Based on this definition, Einstein is the main originator of the modern understanding of special relativity. In his opinion, Lorentz interpreted the Lorentz transformation only as a mathematical device, while Poincaré's thinking was much nearer to the modern understanding of relativity. Yet Poincaré still believed in the dynamical effects of the aether and distinguished between observers being at rest or in motion with respect to it. Stachel wrote: "He never organized his many brilliant insights into a coherent theory that resolutely discarded the aether and the absolute time or transcended its electrodynamic origins to derive a new kinematics of space and time on a formulation of the relativity principle that makes no reference to the ether".Peter Galison (2002)
In his book Einstein's clocks, Poincaré's maps, Peter Galison compared the approaches of both Poincaré and Einstein to reformulate the concepts of space and time. He wrote: "Did Einstein really discover relativity? Did Poincaré already have it? These old questions have grown as tedious as they are fruitless." This is because it depends on the question, which parts of relativity one considers as essential: the rejection of the aether, the Lorentz transformation, the connection with the nature of space and time, predictions of experimental results, or other parts. For Galison, it is more important to acknowledge that both thinkers were concerned with clock synchronization problems, and thus both developed the new operational meaning of simultaneity. However, while Poincaré followed a constructive approach and still adhered to the concepts of Lorentz's stationary aether and the distinction between "apparent" and "true" times, Einstein abandoned the aether and therefore all times in different inertial frames are equally valid. Galison argued that this does not mean that Poincaré was conservative, since Poincaré often alluded to the revolutionary character of the "new mechanics" of Lorentz.Olivier Darrigol (2004)
In his 2004 article, "The Mystery of the Einstein-Poincaré Connection", Darrigol wrote:- "By 1905 Poincaré's and Einstein's reflections on the electrodynamics of moving bodies led them to postulate the universal validity of the relativity principle, according to which the outcome of any conceivable experiment is independent of the inertial frame of reference in which it is performed. In particular, they both assumed that the velocity of light measured in different inertial frames was the same. They further argued that the space and time measured by observers belonging to different inertial systems were related to each other through the Lorentz transformations. They both recognized that the Maxwell-Lorentz equations of electrodynamics were left invariant by these transformations. They both required that every law of physics should be invariant under these transformations. They both gave the relativistic laws of motion. They both recognized that the relativity principle and the energy principle led to paradoxes when conjointly applied to radiation processes. On several points - namely, the relativity principle, the physical interpretation of Lorentz's transformations, and the radiation paradoxes - Poincaré's relevant publications antedated Einstein's relativity paper of 1905 by at least five years, and his suggestions were radically new when they first appeared. On the remaining points, publication was nearly simultaneous."
- "I turn now to basic conceptual differences. Einstein completely eliminated the ether, required that the expression of the laws of physics should be the same in any inertial frame, and introduced a "new kinematics" in which the space and time measured in different inertial systems were all on exactly the same footing. In contrast, Poincaré maintained the ether as a privileged frame of reference in which "true" space and time were defined, while he regarded the space and time measured in other frames as only "apparent." He treated the Lorentz contraction as a hypothesis regarding the effect of the edgewise motion of a rod through the ether, whereas for Einstein it was a kinematic consequence of the difference between the space and time defined by observers in relative motion. Einstein gave the operational meaning of time dilation, whereas Poincaré never discussed it. Einstein derived the expression of the Lorentz transformation from his two postulates, whereas Poincaré obtained these transformations as those that leave the Maxwell-Lorentz equations invariant. Whereas Einstein, having eliminated the ether, needed a second postulate, in Poincaré's view the constancy of the velocity of light derived from the assumption of a stationary ether. Einstein obtained the dynamics of any rapidly moving particle by the direct use of Lorentz covariance, whereas Poincaré reasoned according to a specific model of the electron built up in conformity with Lorentz covariance. Einstein saw that Poincaré's radiation paradoxes could be solved only by assuming the inertia of energy, whereas Poincaré never returned to this question. Lastly, Poincaré immediately proposed a relativistic modification of Newton's law of gravitation and saw the advantages of a four-vector formalism in this context, whereas Einstein waited a couple of years to address this problem complex."
- "These differences between the two theories are sometimes regarded as implying different observable predictions even within the domain of electromagnetism and optics. In reality, there is no such disagreement, for Poincaré's ether is by assumption perfectly undetectable, and every deduction made in Einstein's theory can be translated into a deduction in Poincaré's theory..."
- In sum, then, Einstein could have borrowed the relativity principle, the definition of simultaneity, the physical interpretation of the Lorentz transformations, and the radiation paradoxes from Poincaré.... The wisest attitude might be to leave the coincidence of Poincaré's and Einstein's breakthroughs unexplained,...
Anatoly Alexeevich Logunov on special relativity (2004)
On p. 142, Logunov points out that Einstein wrote reviews for the Beiblätter Annalen der Physik, writing 21 reviews in 1905. In his view, this contradicts the claims that Einstein worked in relative isolation and with limited access to the scientific literature. Among the papers reviewed in the Beiblätter in the fourth issue of 1905, there is a review of Lorentz' 1904-paper by Richard Gans, which contains the Lorentz transformations. In Logunov's view, this supports the view that Einstein was familiar with the Lorentz' paper containing the correct relativistic transformation in early 1905, while his June 1905 paper does not mention Lorentz in connection with this result.
Harvey R. Brown (2005)
wrote about the road to special relativity from Michelson to Einstein in section 4:Regarding Lorentz's work before 1905, Brown wrote about the development of Lorentz's "theorem of corresponding states" and then continued:
Then the contribution of Poincaré's to relativity:
However, Brown continued with the reasons which speak against Poincaré's co-discovery:
Brown denies the idea of other authors and historians, that the major difference between Einstein and his predecessors is Einstein's rejection of the aether, because, it is always possible to add for whatever reason the notion of a privileged frame to special relativity, as long as one accepts that it will remain unobservable, and also Poincaré argued that "some day, no doubt, the aether will thrown aside as useless". However, Brown gave some examples, what in his opinion were the new features in Einstein's work:
After that, Brown develops his own dynamical interpretation of special relativity as opposed to the kinematical approach of Einstein's 1905 paper, and the modern understanding of space-time.
Roger Cerf (2006)
Roger Cerf gave priority to Einstein for developing special relativity, and criticized the assertions of Leveugle and others concerning the priority of Poincaré. While Cerf agreed that Poincaré made important contributions to relativity, he argued that Poincaré "stopped short before the crucial step" because he handled length contraction as a "third hypothesis", therefore Poincaré lacked a complete understanding of the basic principles of relativity. "Einstein's crucial step was that he abandoned the mechanistic ether in favor of a new kinematics." He also denies the idea, that Poincaré invented E=mc² in its modern relativistic sense, because he did not realize the implications of this relationship. Cerf considers Leveugle's Hilbert-Planck-Einstein connection an implausible conspiracy theory.Shaul Katzir (2005)
Katzir argued that "Poincaré's work should not be seen as an attempt to formulate special relativity, but as an independent attempt to resolve questions in electrodynamics." Contrary to Miller and others, Katzir thinks that Poincaré's development of electrodynamics led him to the rejection of the pure electromagnetic world-view, and Poincaré's theory represents a "relativistic physics" which is guided by the relativity principle. In this physics, however, "Lorentz's theory and Newton's theory remained as the fundamental bases of electrodynamics and gravitation."Scott Walter (2005, 2007)
Walter argues that both Poincaré and Einstein put forward the theory of relativity in 1905. And in 2007 he wrote, that although Poincaré formally introduced four-dimensional spacetime in 1905/6, he was still clinging to the idea of "Galilei spacetime". That is, Poincaré preferred Lorentz covariance over Galilei covariance when it is about phenomena accessible to experimental tests; yet in terms of space and time, Poincaré preferred Galilei spacetime over Minkowski spacetime, and length contraction and time dilation "are merely apparent phenomena due to motion with respect to the ether". This is the fundamental difference in the two principal approaches to relativity theory, namely that of "Lorentz and Poincaré" on one side, and "Einstein and Minkowski" on the other side.General relativity
E.T. Whittaker
Whittaker stated that David Hilbert had derived the theory of General Relativity from an elegant variational principle almost simultaneously with Einstein's discovery of the theory.Albrecht Fölsing on the Hilbert-Einstein interaction (1993)
From Fölsing's 1993 Einstein biography " Hilbert, like all his other colleagues, acknowledged Einstein as the sole creator of relativity theory."Cory/Renn/Stachel and Friedwardt Winterberg (1997/2003)
In 1997, Cory, Renn and Stachel published a 3-page article in Science entitled "Belated Decision in the Hilbert-Einstein Priority Dispute" , concluding that Hilbert had not anticipated Einstein's equations.Friedwardt Winterberg, a professor of physics at the University of Nevada, Reno, disputed these conclusions, observing that the galley proofs of Hilbert's articles had been tampered with - part of one page had been cut off. He goes on to argue that the removed part of the article contained the equations that Einstein later published, and he wrote that the cut off part of the proofs suggests a crude attempt by someone to falsify the historical record. "Science" declined to publish this; it was printed in revised form in "Zeitschrift für Naturforschung", with a dateline of June 5, 2003. Winterberg criticized Corry, Renn and Statchel for having omitted the fact that part of Hilbert's proofs were cut off. Winterberg wrote that the correct field equations are still present on the existing pages of the proofs in various equivalent forms. In this paper Winterberg asserted that Einstein sought the help of Hilbert and Klein to help him find the correct field equation, without mentioning the research of Fölsing and Sauer according to which Hilbert invited Einstein to Göttingen to give a week of lectures on general relativity in June 1915, which however does not necessarily contradict Winterberg. Hilbert at the time was looking for physics problems to solve.
A short reply to Winterberg's article could be found at ; the original long reply can be accessed via the Internet Archive at . In this reply, Winterberg's hypothesis is called "paranoid" and "speculative". Cory et al. offer the following alternative speculation: "it is possible that Hilbert himself cropped off the top of p. 7 to include it with the three sheets he sent Klein, in order that they not end in mid-sentence."
As of September 2006, the Max Planck Institute of Berlin has replaced the short reply with a note saying that the Max Planck Society "distances itself from statements published on this website concerning Prof. Friedwart Winterberg" and stating that "the Max Planck Society will not take a position in scientific dispute".
Ivan Todorov, in a paper published on ArXiv, says of the debate:
In the paper recommended by Todorov as calm and non-confrontational, Tilman Sauer concludes that the printer's proofs show conclusively that Einstein did not plagiarize Hilbert, stating
Max Born's letters to David Hilbert, quoted in Wuensch, are quoted by Todorov as evidence that Einstein's thinking towards general covariance was influenced by the competition with Hilbert.
Todorov ends his paper by stating:
Christopher Jon Bjerknes (2003)
Christopher Jon Bjerknes' book focuses on antagonizing the general relativity priority claims in favour of Einstein expressed by Leo Corry and John Stachel regarding Hilbert-Einstein equations of gravity.Anatoly Alexeevich Logunov on general relativity (2004)
, is author of a and coauthor, with Mestvirishvili and Petrov, of an article rejecting the conclusions of the Corry/Renn/Stachel paper. They discuss both Einstein's and Hilbert's papers, claiming that Einstein and Hilbert arrived at the correct field equations independently. Specifically, they conclude that:Wuensch and Sommer (2005)
Daniela Wuensch, a historian of science and a Hilbert and Kaluza expert, responded to Bjerknes, Winterberg and Logunov's criticisms of the Corry/Renn/Stachel paper in a , wherein she defends the view that the cut to Hilbert's printer proofs was made in recent times. Moreover, she presents a theory about what might have been on the missing part of the proofs, based upon her knowledge of Hilbert's papers and lectures.She defends the view that knowledge of Hilbert's November 16, 1915 letter was crucial to Einstein's development of the field equations: Einstein arrived at the correct field equations only with Hilbert's help, but nevertheless calls Einstein's reaction "understandable" because Einstein had worked on the problem for a long time.
According to her publisher, Klaus Sommer, Wuensch concludes though that:
In 2006, Wuensch was invited to give a talk at the annual meeting of the German Physics Society about her views about the priority issue for the field equations.
Wuensch's publisher, Klaus Sommer, in an article in "Physik in unserer Zeit", supported Wuensch's view that Einstein obtained some results not independently but from the information obtained from Hilbert's November 16 letter and from the notes of Hilbert's talk. While he does not call Einstein a plagiarist, Sommer speculates that Einstein's conciliatory December 20 letter was motivated by the fear that Hilbert might comment on Einstein's behaviour in the final version of his paper. Sommer claimed that a scandal caused by Hilbert could have done more damage to Einstein than any scandal before.