Criticism of the theory of relativity

Criticism of Albert Einstein's theory of relativity was especially expressed in the years after its publication on a scientific, pseudoscientific, philosophical, and ideological basis. Reasons for criticism were, for example, alternative theories, rejection of the abstract-mathematical method, misunderstandings, and alleged errors in the theory. Besides those reasons, antisemitism occasionally played a role as well. Also today there are some critics of relativity (sometimes called "anti-relativists"), however, their views are not taken seriously by the scientific community, since the theory of relativity is considered to be self-consistent, is verified by many experimental verifications, and serves as the basis of many successful theories such as quantum electrodynamics.

Physical criticism

Relativity principle contra electromagnetic worldview

Especially by the works of Joseph Larmor (1897) and Wilhelm Wien (1900) the view was widespread, that all forces in nature are of electromagnetic origin ("electromagnetic worldview"). This was apparently confirmed by the experiments of Walter Kaufmann (1901-1903), who approximately measured an increase of the mass with velocity, as it was expected when the mass of the body were generated by its electromagnetic field. Max Abraham (1902) subsequently sketched a theoretical explanation of Kaufmann's results, in which the electron was considered as rigid and spherical.

However, it was found that this model was incompatible with the result of many experiments (including the Michelson-Morley experiment, the Experiments of Rayleigh and Brace, and the Trouton-Noble experiment), by which no "absolute" motion of an observer with respect to the luminiferous aether ("aether drift") could be observed. This impossibility was called by Henri Poincaré (1902) the principle of relativity. Therefore Hendrik Antoon Lorentz (1904) created a model (Lorentz ether theory) that was based on an immobile aether, and contrary to the theory of Abraham, it included effects like length contraction and local time - both are part of the Lorentz transformation. Abraham (1904) criticized, that a) length contraction requires a non-electromagnetic force to ensure the electron's stability, which was unacceptable for a proponent of the electromagnetic worldview. And b) he doubted the possibility that a model based on the relativity principle could be formulated at all. However, Poincaré (1905/6) could show that b) is not incompatible with the relativity principle, when a non-electric potential ("Poincaré stress") is assumed, which is subjected to the Lorentz transformation. Poincaré also assumed the non-electric nature of gravitation. Thus a) and the electromagnetic worldview had to be given up. Eventually, Albert Einstein published in September 1905 what is now called special relativity, which was based on a radical new view of the relativity principle in connection with the constancy of the speed of light in all inertial frames of reference. In special relativity, space and time are relative and the aether doesn't exist at all. Although this theory was founded on a complete different basis, it was experimentally indistinguishable from the aether theory of Lorentz and Poincaré, since both theories employ the Lorentz transformation.

Experimental "refutations"

To bring a conclusive decision between the theories of Abraham and Lorentz, Kaufmann repeated his experiments in 1905 with improved accuracy. However, in the meantime the theoretical situation has changed. Alfred Bucherer and Paul Langevin (1904) developed another model, in which the electron is contracted in the line of motion, and dilated in the transverse direction, so that the volume remains constant. And while Kaufmann still evaluated his experiments, Einstein published his theory of special relativity. Eventually, Kaufmann published his results in December 1905 and argued, that they are in agreement with Abraham's theory, and contain the rejection of the "basic assumption of Lorentz and Einstein" (i.e. the relativity principle). Lorentz reacted with the phrase "I am at the end of my lating", while Einstein mentioned those experiments not before 1908. Yet, others started to criticize the experiments. Max Planck (1906) alluded to inconsistencies in the theoretical interpretation of the data, and Adolf Bestelmeyer (1906) introduced new techniques, which (especially in the area of low velocities) gave different results and which casted doubts on Kaufmann's methods. Therefore Bucherer (1908) conducted new experiments and arrived at the conclusion, that they confirm the mass formula of relativity, and thus the "relativity principle of Lorentz and Einstein". Yet, also those experiments were criticized by Bestelmeyer, which caused a sharp dispute between both experimentalists. On the other hand, additional experiments of Hupka (1910), Neumann (1914) and others seemed to confirm Bucherer's result. But the doubts lasted until 1940, when in similar experiments Abraham's theory was conclusively disproved. (It must be remarked that besides those experiments, the relativistic mass formula was confirmed already in 1917 in the course of investigations on the theory of spectra. And in modern particle accelerators, the relativistic mass formula is routinely confirmed.)

Another discussion concerned the experiments of Dayton Miller. He was known for his repetitions of the Michelson-Morley experiment in 1902-1906 together with Edward Williams Morley. They confirmed the negative result of the initial experiment. However, between 1921-1926 Miller conducted new experiments which apparently gave positive results. Those experiments attracted some attention in the media, yet they were refuted by the scientific community. Einstein ironically remarked "subtle is the Lord, but malicious He is not". Einstein, Max Born, and Robert S. Shankland criticized, that Miller hadn't appropriately considered the influence of temperature. And a modern analysis by Roberts shows, that Miller's experiment gives a negative result, when the technical shortcomings of the apparatus and the error bars are properly considered. Additionally, Miller's result are in disagreement with all other experiments, which were conducted before and after. For example, Georg Joos (1930) used an apparatus of similar dimensions as Miller's, but he obtained negative results. And in recent experiments of Michelson-Morley type, the effective wave length is considerably increased by using Laser and Maser – the results are still negative.

Acceleration in special relativity

It was also claimed, that special relativity cannot handle acceleration, which would lead to contradictions in some situations. However, this assessment is not correct, since accelerations actually can be described in the framework of special relativity (see Hyperbolic motion, Rindler coordinates, Born coordinates). Insufficient understanding of these facts led to the creation paradoxes in the first years of relativity.

For example, Max Born (1909) tried to combine the concept of rigid bodies with special relativity. This model was insufficient as it was shown by Paul Ehrenfest (1909), who demonstrated that a rotating rigid body would, according to Born's definition, undergo a contraction of the circumference without contraction of the radius, which is impossible (Ehrenfest paradox). Yet it was shown by Max von Laue (1911), that rigid bodies cannot exist in special relativity, since the propagation of signals cannot exceed the speed of light, so an accelerating and rotating body will undergo deformations.

As it was shown by Paul Langevin and von Laue, also the twin paradox can completely accounted for by special relativity. If two twins move away from each other, and one of them is accelerating and coming back to the other, then the accelerated twin is younger than the other one, since he was located in at least two inertial frames of references, and therefore his assessment of simultaneous events has changed after the acceleration. For the other twin nothing changes since he remained in a single frame.

Another example is the Sagnac effect. Two signals were sent in opposite directions around a rotating platform. After their arrival a displacement of the interference fringes occurs. Sagnac himself believed that he proved the existence of the aether. However, also in special relativity the result can be easily explained. When viewed from an inertial frame of reference, it is a simple consequence of the independence of the speed of light from the speed of the source, since the receiver runs away from the beam, while it approaches the other beam. And when viewed from a rotating frame, the assessment of simultaneity changes during the rotation, and consequently the speed of light is not constant in accelerated frames.

As it was shown by Einstein, the only form of accelerated motion that cannot be described is the one due to gravitation, since special relativity is not compatible to the Equivalence principle. Einstein was also unsatisfied with the fact, that inertial frames are preferred over accelerated frames. Thus in the course of several years (1908-1915), Einstein developed general relativity. This theory includes the replacement of Euclidean geometry by non-Euclidean geometry, and the resultant curvature of the path of light led Einstein (1912) to the assessment, that (like in accelerated frames) the speed of light is not constant in extended gravitational fields. Therefore, Abraham (1912) argued that Einstein has given to special relativity a Coup de grâce ("Gnadenstoß"). Einstein responded, that within its area of application (in areas were gravitational influences can be neglected) special relativity is still applicable with high precision, so one cannot speak of a coup de grâce at all.

Superluminal speeds

In special relativity, the transfer of signals at superluminal speeds is impossible, since this would violate the Poincaré-Einstein synchronization, and the causality principle. Following an old argument by Pierre-Simon Laplace, Poincaré (1904) alluded to the fact, that Newton's law of universal gravitation is founded on an infinitely great speed of gravity. So the clock-synchronization by light signals could in principle be replaced by a clock-synchronization by instantaneous gravitational signals. But in 1905, Poincaré himself solved this problem by showing, that in a relativistic theory of gravity the speed of gravity is equal to the speed of light. Although much more complicated, this is also the case in Einstein's theory of general relativity.

Another apparent contradiction lies in the fact, that the group velocity in dispersive media is higher than the speed of light. This was investigated by Arnold Sommerfeld (1907, 1914) and Léon Brillouin (1914). They came to the conclusion that in such cases the signal velocity is not equal to the group velocity, but to the front velocity which is never faster than the speed of light. Similarly, it is also argued that the apparent superluminal effects discovered by Günther Nimtz can be explained by a thorough consideration of the velocities involved.

Also quantum entanglement (denoted by Einstein as "spooky action at a distance"), according to which the quantum state of distant particles cannot be fully described without describing the other particle, cannot be used for superluminal transmission of information (see quantum teleportation, and it is therefore in conformity with special relativity.

Paradoxes

Insufficient knowledge of the basics of special relativity, especially the application of the Lorentz transformation in connection with length contraction and time dilation, led and still leads to the construction of various apparent paradoxes. Both the twin paradox and the Ehrenfest paradox and their explanation were already mentioned above. Besides the twin paradox, also the reciprocity of time dilation (i.e. every inertially moving observer considers the clock of the other one as being dilated) was heavily criticized by Herbert Dingle and others. For example, Dingle wrote a series of letter to Nature at the end of the 1950ies. However, also the self-consistency of the reciprocity of time dilation was already proven by Lorentz and many others long before - it is only necessary to carefully consider the relevant measurement rules and the relativity of simultaneity. Other known paradoxes are the Ladder paradox and Bell's spaceship paradox, which also can simply be solved by consideration of the relativity of simultaneity.

Aether and absolute space

Some physicists (like Oliver Joseph Lodge, Albert Abraham Michelson, Edmund Taylor Whittaker, Harry Bateman, Ebenezer Cunningham, Charles Émile Picard, Paul Painlevé, Herbert E. Ives) were uncomfortable with the rejection of the aether, and tried to interpret the Lorentz transformation by using a preferred frame of reference like in the older aether-based theories of Lorentz, Larmor, and Poincaré. This was in connection with the problem, as to how the theories of Lorentz and Einstein are to be distinguished. However, on one hand the aether plays the role of a preferred reference frame, but on the other hand it shall be unobservable due to a "conspiracy" of effects. This combination was considered very improbable, so (except the minority mentioned above) most physicists preferred Einstein's theory as a radical new view of space and time, and there was no place for the aether in the classical sense within modern physics anymore.

Another attempt to re-establish some sort of aether (at least in a literal sense) was made by Einstein in some semi-popular papers in the 1920ies. This was concluded by him as a consequence of the failure of Mach's principle, i.e. that in general relativity space-time itself has physicals properties. However, this terminology was not accepted by the scientific community, since no state of motion can be ascribed to this "aether". Also the attempts of Paul Dirac (1953), to re-interpret the quantum vacuum as an aether equipped with a state of motion, were not successful. And in his nobel lecture, George F. Smoot described his own experiments on Cosmic microwave background radiation as "New Aether drift experiments". However, as pointed out by Smoot, this "Aether drift" is not in contradiction to special relativity or the Michelson-Morley experiment, since it only refers to a reference frame, in which the CMBR is isotropic and in which the description of the Big Bang is most convenient.

Alternative theories

The theory of complete aether drag, as proposed by George Gabriel Stokes (1844), was used by some critics as Ludwig Silberstein (1917) or Philipp Lenard (1919) as a counter-model of relativity. In this theory, the aether was completely dragged within and in the vicinity of matter, and it was believed that various phenomena, such as the absence of aether drift, could be explained in an "illustrative" way by this model. However, such theories are subject to great difficulties. Especially the aberration of light contradicted the theory, and all auxiliary hypotheses, which were invented to rescue it, are self-contradictory, extremely implausible, or in contradiction to other experiments like the Michelson–Gale–Pearson experiment. In summary, a sound mathematical and physical model of complete aether drag was never invented, consequently this theory was no serious alternative of relativity.

Another alternative was the so called emission theory of light. As in special relativity the aether concept is discarded, yet the main difference to relativity lies in the fact, that the velocity of the light source is added to that of light in accordance with the Galilean transformation. As the hypothesis of complete aether drag, it can explain the negative outcome of all aether drift experiments. Yet, there are various experiments that contradict this theory. For example, the Sagnac effect is based on the independence of light speed from the source velocity, and the image of Double stars should be scrambled according to this model - which was not observed. Also in modern experiments in particle accelerators no such velocity dependence could be observed.

Philosophical criticism

The consequences of relativity, such as the change of ordinary concepts of space and time, as well as the introduction of non-Euclidean geometry in general relativity, were criticized by some philosophers of different philosophical schools. It was characteristic for many philosophical critics, that they had insufficient knowledge of the mathematical and formal basis of relativity, consequently the criticisms often missed the heart of the matter. For example, relativity was misinterpreted as some form of relativism. However, this is misleading as it was emphasized by Einstein or Planck. On one hand it's true that space and time became relative, and the inertial frames of reference are handled on equal footing. On the other hand the theory makes natural laws invariant - examples are the constancy of the speed of light, or the covariance of Maxwell's equations. Consequently, Felix Klein (1910) called it the "invariant theory of the Lorentz group" instead of relativity theory, and Einstein (who also used expressions like "absolute theory") sympathized with this expression as well.

Critical responses to relativity (in German speaking countries) were also expressed by proponents of Neo-Kantianism (Paul Natorp, Bruno Bauch, Ernst Marcus, Salomo Friedlaender, Lenore Kühn), and Phenomenology (Oskar Becker, Moritz Geiger). While some of them only rejected the philosophical consequences, others rejected also the physical consequences of the theory. Einstein was criticized for violating Immanuel Kant's categoric scheme, i.e., it was claimed that space-time curvature caused by matter and energy is impossible, since matter and energy already require the concepts space and time. Also the three-dimensionality of space and the existence of absolute simultaneity was claimed to be necessary for the understanding of the world - all of those things were thought to be concepts that cannot be altered by empirical findings. Hentschel (1990) criticized this arguments as "Strategies of Immunization". By moving all those concepts into an area that cannot be altered by empirical results, any form of criticism of Kantianism would be prevented. Additionally, he argued that also Kant's philosophy is the product of his time, i.e. Kant used Newton's theories as the basis of many of his philosophical expressions. This was the reason, why other Kantians like Ernst Cassirer or Hans Reichenbach (1920), tried to modify Kant's philosophy. Subsequently, Reichenbach rejected Kantianism at all and became a proponent of logical positivism.

Based on Henri Poincaré's [[conventionalism|], philosophers such as Pierre Duhem (1914) or Hugo Dingler (1920) argued that the classical concepts of space, time, and geometry were, and will always be, the most convenient expressions in natural science, therefore the concepts of relativity cannot be correct. This was criticized by proponents of logical positivism such as Moritz Schlick, Rudolf Carnap, or Reichenbach. They argued that Poincaré's conventionalism could be modified, as to bring it into accord with relativity. Although it's true, that the basis assumptions of Newtonian mechanics are more simple, it can only be brought into accord with modern experiments by inventing auxiliary hypothesis. On the other hand, relativity doesn't need such hypothesis, thus from a conceptual viewpoint, relativity is in fact more simple than Newtonian mechanics.

Some proponents of Philosophy of Life, Vitalism, Critical realism (in German speaking countries) argued that there is a fundamental difference between physical, biological and psychological phenomena. For example, Henri Bergson (1921), who otherwise was a proponent of special relativity, argued that time dilation cannot be applied to biological organisms, therefore he denied the relativistic solution of the twin paradox. However, those claims were rejected by Paul Langevin, André Metz and others. Biological organisms consist of physical processes, so there is no reason to assume that they are not subject to relativistic effects like time dilation.

Based on the philosophy of Fictionalism, Oskar Kraus (1921) and others claimed, that the foundations of relativity are only fictitious and even self-contradictory. Examples were the constance of the speed of light, time dilation, length contraction, which as a whole appear to be mathematical consistent, but in reality they are not true. Yet, those claims were immediately rejected. The foundations of relativity (like the equivalence principle or the relativity principle) are not fictitious, but based on experimental results. Also effects like constancy of the speed of light and relativity of simultaneity are not contradictory, but complementary to one another.

In the Soviet union (mostly in the 1920ies), philosophical criticism was expressed on the basis of dialectic materialism. The theory of relativity was rejected as anti-materialistic and speculative, and a mechanistic worldview based on "common sense" was required as an alternative. Similar criticisms also occurred in the People's Republic of China during the Cultural Revolution. (On the other hand, other philosophers considered relativity as being compatible with Marxism)

Relativity hype and popular criticism

Although Planck already in 1909 compared the changes brought about by relativity with the Copernican Revolution, and although special relativity was accepted by most of the theoretical physicists and mathematicians by 1911, it was not before publication of the experimental results of the group around Arthur Stanley Eddington (1919), that relativity was globally noticed - also within the public. Einstein was praised in the mass media, and he was compared to Nikolaus Copernicus, Johannes Kepler and Isaac Newton. This fame led to a popular "relativity hype" ("Relativitätsrummel", as it was called by Sommerfeld, Einstein, and others), but it also caused a counter-reaction of some scientists and scientific laymen. The controversy (untypical for scientific discussions) was partly carried out in the press, and the criticism was not only directed to relativity, but personally to Einstein as well.

Academic and non-academic criticism

Some academic scientists, especially experimental physicists such as the nobel laureates Philipp Lenard and Johannes Stark, as well as Ernst Gehrcke, Stjepan Mohorovičić, and Rudolf Tomaschek etc. criticized the increasing mathematization of modern physics, especially in the form of relativity theory and quantum theory. It was seen as a tendency to abstract theory building, connected with the loss of "common sense". In fact, relativity was the first theory, in which the inadequacy of the "illustrative" classical physics was clearly demonstrated. The critics ignored these developments and tried to revitalize older theories, such as aether drag models or emission theories (see "Alternative Theories"). However, those qualitative models were never sufficiently advanced to compete with the success of the precise experimental predictions and explanatory powers of the modern theories. Additionally, there was also a great rivalry between experimental and theoretical physicists, as regards the professorial activities and the occupation of chairs at German universities. The opinions clashed at the "Bad Nauheim debate" in 1920 between Einstein and Lenard, which attracted much attention in the public.

In addition, there were many critics (with or without physical training) whose ideas were far outside the scientific mainstream. These critics were mostly people who had developed their ideas long before the publication of the theory of relativity and they tried resolve in a straightforward manner some or all enigma of the world. Therefore, Wazeck (who studied some German examples) gave to these "free researchers" the name "world riddle solver" (Welträtsellöser). Their views had their quite different roots in monism, Lebensreform, or occultism. Their methods were characterized by the fact that they practically rejected the entire terminology and the (primarily mathematical) methods of modern science. Their works were published by private publishers, or in popular and non-specialist journals. It was significant for many "free researchers" (especially the monists) to explain all phenomena by intuitive and illustrative mechanical (or electrical) models, which also found its expression in their defense of the aether. Therefore they rejected the inscrutability of the relativity theory, which was considered a pure calculation method that cannot reveal the true reasons behind things. The "free researchers" often used Mechanical explanations of gravitation, in which gravity is caused by some sort of "aether pressure" or "mass pressure from a distance". Such models were regarded as an illustrative alternative to the abstract mathematical theories of gravitation of both Newton and Einstein. Additionally, also the enormous self-confidence of the "free researchers" is noteworthy, since they not only believed to have solved all the riddles of the world, but also had the expectation that they would rapidly convince the scientific community.

Since Einstein rarely defended himself against these attacks, this task was overtaken by other relativity theoreticians, who (according to Hentschel) formed some sort of "defensive belt" around Einstein. Some representatives were Max von Laue, Max Born, etc. and on popular-scientific and philosophical level Hans Reichenbach, André Metz etc., who led many discussions with critics in semi-popular journals and newspapers. However, most of these discussion were failing from the start. Physicists like Gehrcke, some philosophers, and the "free researchers" were so obsessed with their own ideas and prejudices, that they were unable to grasp the basics of relativity, consequently the participants of the discussions were talking past each other. In fact, the theory which was criticized by them was not relativity at all, but rather a caricature of it. The "free researchers" were mostly ignored by the scientific community, but with time also respected physicists such as Lenard and Gehrcke found themselves in a position outside the scientific community. However, the critics didn't believed that this was due to their incorrect theories, but rather due to a conspiracy of the relativistic physicists (and in the 1920-1930ies of the Jews as well), which allegedly tried to put down the critics, and to preserve and improve their own positions within the academic world. For example, Gehrcke (1920/24) held that the propagation of relativity is a product of some sort of mass suggestion. Therefore he instructed a Media monitoring service to collect over 5000 newspaper clippings which were related to relativity, and published his findings in a book. However, Gehrcke's claims were rejected, because the simple existence of the "relativity hype" says nothing about the validity of the theory, and thus it cannot used for or against relativity.

Afterwards, some critics tried to improve their positions by the formation of alliances. One of them was the "Acadamy of Nations", which was founded in 1921 in the USA by Robert T. Browne and Arvid Reuterdahl. Other members were Thomas Jefferson Jackson See, as well as Gehrcke and Mohorovičić in Germany. However, the alliance disappeared already in the mid 1920ies in Germany and 1930 in the USA.

Chauvinism and antisemitism

Shortly before and during World War I, there appeared some nationalistically motivated criticsisms of relativity and modern physics. For example, Pierre Duhem regarded relativity as the product of the "too formal and abstract" German spirit, which was in conflict with the "common sense". Similarly, also the popular criticism in the Soviet union and China, which partly were politically organized, rejected the theory not because of factual objections, but ideologically motivated as the product of western decadence.

So in those countries, the Germans or the Western civilization were the enemies. However, in Germany it was the Jewish ancestry of relativity proponents such as Einstein, Minkowski, Born, which made them to targets of racist critics (this of course does not mean that all or most of German critics had such motives.) For example, Paul Weyland was a known nationalistic agitator who arranged the first public meeting against relativity in Berlin in 1919, and also Lenard and Stark were known for their nationalistic opinions. While they avoided antisemitic claims in their first publications, it was clear for many, that antisemitism played a role. Reacting to this underlying moods, Einstein openly speculated in a newspaper article, that besides insufficient knowledge of theoretical physics also antisemitism was a reasons of their criticisms. Some critics, including Weyland, reacted angrily and claimed that such accusations of antisemitism were only made to force the critics into silence. However, from now on Weyland, Lenard, Stark and others clearly showed their antisemitic prejudices by beginning to combine their criticisms with racism. For example, Theodor Fritsch emphasized the alleged negative consequences of the "Jewish spirit" within relativity, and the far right-press continued this propaganda unhinderedly. After the murder of Walther Rathenau (1922) and murder threats against Einstein, he left for some time Berlin. Gehrcke's book on "The mass suggestion of relativity theory" (1924) was not antisemitic itself, however, it was praised by the far-right press as describing an alleged typical Jewish behavior. Philipp Lenard (1922) spoke about the "foreign spirit" as the foundation of relativity, and afterwards he joined the Nazi party in (1924), and Johannes Stark did the same in (1930). Bot were proponents of the so called German Physics, which only accepted scientific knowledge based on experiments, and which are accessible to the senses. According to Lenard (1936), this is the "Arian physics or physics by man of nordic kind" as opposed to the alleged formal-dogmatic "Jewish physics". Additional antisemitic critics can be found in the writings of Wilhelm Müller, Bruno Thüring and others. For example, Müller claimed that relativity is a pure "Jewish affair" and it would correspond to the "Jewish essence" etc, while Thüring constructed comparisons between the talmud and relativity.

Accusations of plagiarism and priority discussions

Some critics like Lenard, Gehrcke, Reuterahl called Einstein a plagiarist, and they questioned his priority for inventing relativity. On one side, the purpose of those allegations was to allude to non-relativistic alternatives to modern physics, and on the other side, Einstein himself should be discredited. However, it was quickly seen that these accusation were unfounded, since the physical content and the applicability of those former theories were quite different from relativity. Some examples:

• Johann Georg von Soldner (1801) was credited for his calculation of the deflection of light in the vicinity of celestial bodies, long before Einstein's prediction which was based on general relativity. However, Soldner's derivation has nothing to do with Einstein's, since it was fully based on Newton's theory, and only gave half of the value as predicted by general relativity.
• Paul Gerber (1898) published a formula for the perihelion advance of mercury, which was formal identical to an approximate solution given by Einstein. However, since Einstein's formula was only an approximation, the solutions are not identical. In addition, Gerber's derivation has no connection with General relativity and was even considered as meaningless.
• Woldemar Voigt (1887) derived a transformation, which is very similar to the Lorentz transformation. However, as Voigt himself acknowledged, his theory was not based on electromagnetic theory, but on an elastic aether model. His transformation also violates the relativity principle.
• Friedrich Hasenöhrl (1904) applied the concept of electromagnetic mass and momentum (which were known long before) to cavity- and thermal radiation. Yet, the applicability of Einstein's Mass–energy equivalence goes much further, since it is derived from the relativity principle and applies to all forms of energy.
• Menyhért Palágyi (1901) developed a philosophical "space-time" model in which time plays the role of an imaginary fourth dimension. But Palágyi's model was only a reformulation of Newtonian physics, and had no connection of electromagnetic theory, the relativity principle, or the constancy of the speed of light.
• In addition, also some "free researchers" accused Einstein of plagiarizing their works, even if there was only verbal agreement with some of their texts. So, on one hand Einstein was considered a plagiarist, and on the other hand foundational criticism of relativity was expressed. To justify this contradictory behavior, it was assumed that Einstein allegedly stole the ideas, but at the same time he totally misunderstood them and therefore produced his "illogical" theory of relativity. The "free researchers" also constructed some conspiracy theories, which should explain, why Einstein's alleged plagiarisms were tolerated by the scientific community.

Contrary to those unfounded allegations, some modern historians of science still consider the question, whether Einstein was possibly influenced by Poincaré, who offered some interpretations of Lorentz's electron theory that can also be found in special relativity.

Hundred authors against Einstein

A collection of various criticisms can be found in the book "Hundert Autoren gegen Einstein" (Hundred authors against Einstein), published in 1931. It contains very short texts by 28 authors, and excerpts of publications of other 19 authors. The rest consists of a list that also includes persons, which only for some time were opposed to relativity. Besides philosophic objections (mostly based on Kantianism), also some alleged elementary failures of the theory were included, however, as some recipients of the book commented, those failures were due to the misunderstand of the relativity by the authors. For example, Hans Reichenbach described the book as an "accumulation of naive errors", and as "unintentionally funny". Albert von Brunn interpreted the book as a backward step to the 16th and 17th century, and Einstein is reported to have said with irony, that one author alone would have been sufficient to refute him. According to Goenner, the contributions to the book are a mixture of mathematical-physical incompetence, Hybris, and the feelings of the critics of being suppressed by the modern physicists. The compilation of the authors show, Goenner continues, that this was not a reaction within the physics community - only one physicist (Karl Strehl) and three mathematicians (Jean-Marie Le Roux, Emanuel Lasker and Hjalmar Mellin) were present - but an inadequate reaction of the academic educated citizenship, which didn't knew what to do with relativity. As regards the average age of the authors: 57% were substantially older than Einstein, one third was around the same age, and only tow persons were substantially younger. Two authors (Reuterdahl, von Mitis) were antisemites and four others were possibly connected to the Nazi movement. On the other hand, no antisemitic expression can be found in the book, and it also included contributions of some authors of Jewish ancestry (Salomo Friedländer, Ludwig Goldschmidt, Hans Israel, Emanual Lasker, Oskar Kraus, Menyhért Palágyi).

Status of criticism

The theory of relativity is considered to be self-consistent, is verified by many experimental verifications, and serves as the basis of many successful theories like quantum electrodynamics. Therefore, fundamental criticism (like those of Herbert Dingle, Louis Essen, Petr Beckmann, Maurice Allais, Tom van Flandern) were not taken serious by the scientific community, and due to the lack of quality of many critical publications (which have been found in the process of Peer review) they were rarely accepted for publication in reputable scientific journals. So, like in the 1920ies, most of the critical works were published in small publications houses, alternative journals (like "Apeiron" or "Galilean Electrodynamics"), or private websites (like Conservapedia).

However, this does not mean that modern physics won't be further developed. The enormous progress of technologies (by particle accelerations to test special relativity, and by astronomical observations to test general relativity) leads to extremely precises ways to test the predictions of relativity, and so far it successfully passed all tests. In addition, also in the theoretical field there is continuing research to unite general relativity and quantum theory. The most promising models are string theory and loop quantum gravity. Some variations of those models also predict violations of Lorentz invariance on a very small scale.

References

Historic analyses

Beyerchen, Alan D. (1977). Scientists under Hitler. New Haven: Yale University Press. ISBN 0300018304. Chang, Hasok (1993). "A misunderstood rebellion: The twin-paradox controversy and Herbert Dingle's vision of science". Studies in History and Philosophy of Science Part A. 24 (5): 741–790. doi:10.1016/0039-3681(93)90063-P. Darrigol, Olivier (2004). "The Mystery of the Einstein-Poincaré Connection". Isis. 95 (4): 614–626. Goenner, Hubert (1993a). "The reaction to relativity theory I: the Anti-Einstein campaign in Germany in 1920". Science in Context. 6: 107–133. doi:10.1017/S0269889700001332. Goenner, Hubert (1993b). "The reaction to relativity theory in Germany III. Hundred Authors against Einstein". In Earman, John; Janssen, Michel; Norton, John D. (ed.). The Attraction of Gravitation (Einstein Studies). Vol. 5. Boston - Basel: Birkhäuser. pp. 248–273. ISBN 3764336242.{{cite book}}: CS1 maint: multiple names: editors list (link) Hentschel, Klaus (1990). Interpretationen und Fehlinterpretationen der speziellen und der allgemeinen Relativitätstheorie durch Zeitgenossen Albert Einsteins. Basel - Boston - Bonn: Birkhäuser. ISBN 3764324384. Hu, Danian (2007). "The Reception of Relativity in China". Isis. 98: 539–557. Janssen, Michel & Mecklenburg, Matthew (2007). "From classical to relativistic mechanics: Electromagnetic models of the electron". In V. F. Hendricks; et al. (eds.). Interactions: Mathematics, Physics and Philosophy. Dordrecht: Springer. pp. 65–134. {{cite book}}: Explicit use of et al. in: |editor= (help); External link in |chapterurl= (help); Unknown parameter |chapterurl= ignored (|chapter-url= suggested) (help)CS1 maint: multiple names: authors list (link) Janssen, Michel (2008). "'No Success like Failure ...': Einstein's Quest for General Relativity, 1907-1920". To appear in The Cambridge Companion to Einstein (Co-edited with Christoph Lehner).. Katzir, Shaul (2005). "Poincaré's Relativistic Physics: Its Origins and Nature". Physics in perspective. 7: 268–292. doi:10.1007/s00016-004-0234-y. Kleinert, Andreas (1979). "Nationalistische und antisemitische Ressentiments von Wissenschaftlern gegen Einstein". Einstein-Symposion Berlin (Lecture Notes in Physics): 501–516. Kragh, Helge (2005). Dirac. A Scientific Biography. Cambridge: Cambridge University Press. ISBN 0521017564. Mathpages: Herbert Dingle and the Twins; What Happened to Dingle? Miller, Arthur I. (1981). Albert Einstein’s special theory of relativity. Emergence (1905) and early interpretation (1905–1911). Reading: Addison–Wesley. ISBN 0201046792. Norton, John D. (2004). "Einstein's Investigations of Galilean Covariant Electrodynamics prior to 1905". Archive for History of Exact Sciences. 59: 45–105. Norton, John D. (2008). "The Hole Argument". In Edward N. Zalta (ed.). The Stanford Encyclopedia of Philosophy (Winter 2008 Edition). {{cite book}}: External link in |chapterurl= (help); Unknown parameter |chapterurl= ignored (|chapter-url= suggested) (help). Pais, Abraham (1982/2000). Subtle Is the Lord. Oxford: University Press. ISBN 0192806726. {{cite book}}: Check date values in: |year= (help) Paty, Michel (1987). "The scientific reception of relativity in France". In Glick, T.F. (ed.). The Comparative Reception of Relativity. Dordrecht: Kluwer Academic Publishers. pp. 113–168. ISBN 9027724989. Pauli, Wolfgang (1921). "Die Relativitätstheorie". Encyclopädie der mathematischen Wissenschaften. Vol. 5.2. pp. 539–776. {{cite book}}: External link in |chapterurl= (help); Unknown parameter |chapterurl= ignored (|chapter-url= suggested) (help) Posch, Th., Kerschbaum, F., Lackner, K. (2006). "Bruno Thürings Umsturzversuch der Relativitätstheorie". In Gudrun Wolfschmidt (ed.). Nuncius Hamburgensis - Beiträge zur Geschichte der Naturwissenschaften. Vol. 4. {{cite book}}: External link in |chapterurl= (help); Unknown parameter |chapterurl= ignored (|chapter-url= suggested) (help)CS1 maint: multiple names: authors list (link) Staley, Richard (2009). Einstein's generation. The origins of the relativity revolution. Chicago: University of Chicago Press. ISBN 0226770575. Swenson, Loyd S. (1970). "The Michelson-Morley-Miller Experiments before and after 1905". Journal for the History of Astronomy. 1: 56–78. Vizgin, V. P. & Gorelik G. E. (1987). "The Reception of the Theory of Relativity in Russia and the USSR". In Glick, T.F. (ed.). The Comparative Reception of Relativity. Dordrecht: Kluwer Academic Publishers. pp. 265–326. ISBN 9027724989. Warwick, Andrew (2003). Masters of Theory: Cambridge and the Rise of Mathematical Physics. Chicago: University of Chicago Press. ISBN 0226873757. Wazeck, Milena (2009). Einsteins Gegner: Die öffentliche Kontroverse um die Relativitätstheorie in den 1920er Jahren. Frankfurt - New York: Campus. ISBN 3593389142. Einstein's sceptics: Who were the relativity deniers? Zahar, Elie (2001). Poincare's Philosophy: From Conventionalism to Phenomenology. Chicago: Open Court Pub Co. ISBN 081269435X. Zeilinger, Anton (2005). Einsteins Schleier: Die neue Welt der Quantenphysik. München: Goldmann. ISBN 3442153026.

Relativity papers

Born, Max (1909). "Die Theorie des starren Körpers in der Kinematik des Relativitätsprinzips". Annalen der Physik. 335 (11): 1–56. Brillouin, Léon (1914). "Über die Fortpflanzung des Lichtes in dispergierenden Medien". Annalen der Physik. 349 (10): 203–240. Bucherer, A. H. (1908). "Messungen an Becquerelstrahlen. Die experimentelle Bestätigung der Lorentz-Einsteinschen Theorie." . Physikalische Zeitschrift. 9 (22): 755–762. Carlip, Steve (1999). "Aberration and the Speed of Gravity". Pys. Lett. A. 267: 81–87. {{cite journal}}: External link in |title= (help) Cassirer, Ernst (1921). Zur Einstein'schen Relativitätstheorie. Berlin: Bruno Cassirer Verlag. De Sitter, Willem (1913). "Ein astronomischer Beweis für die Konstanz der Lichtgeschwindigkeit". Physikalische Zeitschrift. 14: 429. DeSitter, Willem (1916a). "On the relativity of rotation in Einstein's theory". Roy. Amst. Proc. 17 (1): 527–532. DeSitter, Willem (1916b). "On the relativity of inertia. Remarks concerning Einstein's latest hypothesis". Roy. Amst. Proc. 17 (2): 1217–1225.. Dirac, Paul (1953). "The Stellung des Aethers in the Physik". Naturwissenschaftliche Rundschau. 6: 441–446.. (Wurde hier eingefügt, da Dirac seine Theorie als mit der speziellen Relativitätstheorie verträglich ansah.) Einstein, Albert (1905). "Zur Elektrodynamik bewegter Körper". Annalen der Physik. 322 (10): 891–921. Einstein, Albert (1908). "Über das Relativitätsprinzip und die aus demselben gezogenen Folgerungen". Jahrbuch der Radioaktivität und Elektronik. 4: 411–462f. Einstein, Albert (1911). "Zum Ehrenfestschen Paradoxon". Physikalische Zeitschrift. 12: 509–510. Einstein, Albert (1912). "Relativität und Gravitation. Erwiderung auf eine Bemerkung von M. Abraham" (PDF). Annalen der Physik. 343 (10): 1059–1064. Einstein, Albert (1916). "Die Grundlage der allgemeinen Relativitätstheorie" (PDF). Annalen der Physik. 49: 769–782. Einstein, A. (1920a). "Meine Antwort - Über die anti-relativitätstheoretische G.m b.H". Berliner Tageblatt. 402. Einstein, Albert (1920b). Äther und Relativitätstheorie. Berlin: Springer. Einstein, Albert (1924). "Über den Äther". Verhandlungen der Schweizerischen naturforschenden Gesellschaft. 105: 85–93.. Fox, J. G. (1965). "Evidence Against Emission Theories". American Journal of Physics. 33 (1): 1–17. doi:10.1119/1.1971219. Joos, Georg (1959). Lehrbuch der theoretischen Physik. Frankfurt am Main: Akademische Verlagsgesellschaft. p. 448. Kretschmann, Erich (1917). "Uber den physikalischen Sinn der Relativitätspostulate. A. Einsteins neue und seine ursprüngliche Relativitätstheorie". Annalen der Physik. 358 (16): 575–614. Langevin, Paul (1911). "L'Évolution de l'espace et du temps" . Scientia. 10: 31–54. Langevin, Paul (1921). "Sur la théorie de relativité et l'expérience de M. Sagnac". Comptes Rendus. 173: 831–834. Langevin, Paul (1937). "Sur l'expérience de Sagnac". Comptes Rendus. 205: 304–306. Laue, Max von (1911). "Zur Diskussion über den starren Körper in der Relativitätstheorie". Physikalische Zeitschrift. 12: 85–87. Laue, Max von (1917). "Die Fortpflanzungsgeschwindigkeit der Gravitation. Bemerkungen zur gleichnamigen Abhandlung von P. Gerber". Annalen der Physik. 358 (11): 214–216. Laue, Max von (1921a). Die Relativitätstheorie. Vol. 1. Braunschweig: Friedr. Vieweg & Sohn.. (Laue gibt hier eine Zusammenfassung seiner Sagnac-Arbeit von 1911, und seiner Lösung zum Zwillingsparadoxon von 1913.) Laue, Max von (1921b). "Erwiderung auf Hrn. Lenards Vorbemerkungen zur Soldnerschen Arbeit von 1801". Annalen der Physik. 371 (20): 283–284. doi:10.1002/andp.19213712005. Liberati, Stefano & Maccione, Luca (2009). "Lorentz Violation: Motivation and new constraints". Annual Review of Nuclear and Particle Science. arXiv:0906.0681.{{cite journal}}: CS1 maint: multiple names: authors list (link) Lorentz, Hendrik Antoon (1904/13). "Elektromagnetische Erscheinungen in einem System, das sich mit beliebiger, die des Lichtes nicht erreichender Geschwindigkeit bewegt" . In Blumenthal, Otto & Sommerfeld, Arnold (ed.). Das Relativitätsprinzip. Eine Sammlung von Abhandlungen. Leipzig und Berlin: B.G. Teubner. pp. 6–26. {{cite book}}: Check date values in: |year= (help)CS1 maint: multiple names: editors list (link) Mattingly, David (2005). "Modern Tests of Lorentz Invariance". Living Rev. Relativity. 8 (5). Metz, André (1923). La Relativité. Paris: Chiron. Michelson, A. A.; Gale, Henry G. (1925). "The Effect of the Earth's Rotation on the Velocity of Light, II". Astrophysical Journal. 61: 140. doi:10.1086/142879.{{cite journal}}: CS1 maint: multiple names: authors list (link). Petzoldt, Joseph (1921). Das Weltproblem vom Standpunkt des relativistischen Positivismus aus, historisch-kritisch dargestellt. Leipzig: B.G. Teubner.. (Wurde hier eingefügt, da Petzoldt seine Philosophie als mit der speziellen Relativitätstheorie verträglich ansah.) Planck, Max (1906a). "Das Prinzip der Relativität und die Grundgleichungen der Mechanik". Verhandlungen Deutsche Physikalische Gesellschaft. 8: 136–141. Planck, Max (1906b). "Die Kaufmannschen Messungen der Ablenkbarkeit der β-Strahlen in ihrer Bedeutung für die Dynamik der Elektronen". Physikalische Zeitschrift. 7: 753–761. Planck, Max (1925). "Vom Relativen zum Absoluten". Naturwissenschaften. 13 (3): 52–59. doi:10.1007/BF01559357. Poincaré, Henri (1906). "Sur la dynamique de l'électron" . Rendiconti del Circolo matematico di Palermo. 21: 129–176.. Siehe auch deutsche Übersetzung. Reichenbach, Hans (1920). Relativitätstheorie und Erkenntnis apriori. Berlin: Springer. Reichenbach, Hans (1924). Axiomatik der relativistischen Raum-Zeit-Lehre. Braunschweig: Vieweg. Roberts, Thomas J.: An Explanation of Dayton Miller's Anomalous "Ether Drift" Result, 2006, arXiv:physics/0608238 Schlick, Moritz (1921). Raum und Zeit in der gegenwärtigen Physik (3. vermehrte Auflage ed.). Berlin: Springer. Smoot, G. F.; (2006), Nobelpreisrede: Cosmic Microwave Background Radiation Anisotropies: Their Discovery and Utilization Sommerfeld, Arnold (1907). "Ein Einwand gegen die Relativtheorie der Elektrodynamik und seine Beseitigung". Physikalische Zeitschrift. 8 (23): 841–842. Sommerfeld, Arnold (1914). "Über die Fortpflanzung des Lichtes in dispergierenden Medien". Annalen der Physik. 349 (10): 177–202. Wallenborn, Ernst-Udo:Physik FAQ, Superluminales Tunneln, 1999 Will, Clifford M. (2006). "The Confrontation between General Relativity and Experiment". Living Rev. Relativity. 9 (3).

Critical works

Abraham, Max (1904). "Die Grundhypothesen der Elektronentheorie" . Physikalische Zeitschrift. 5: 576–579. Abraham, Max (1912). "Relativität und Gravitation. Erwiderung auf eine Bemerkung des Herrn A. Einstein". Annalen der Physik. 343 (10): 1056–1058. Bergson, Henri (1921/3). Durée et simultanéité. A propos de la théorie d'Einstein (second edition). Saint-Germain: Félix Alcan. {{cite book}}: Check date values in: |year= (help) Dingle, Herbert (1972). Science at the Crossroads. London: Martin Brian & O'Keeffe. ISBN 0856160601. Dingler, Hugo (1922). Relativitätstheorie und Ökonomieprinzip. Leipzig: S. Hirzel. Ehrenfest, Paul (1909). "Gleichförmige Rotation starrer Körper und Relativitätstheorie" . Physikalische Zeitschrift. 10: 918. Essen, Louis (1971). The Special Theory of Relativity: A Critical Analysis. Oxford: Oxford University Press. ISBN 0198519214. Fricke, Hermann (1919). Der Fehler in Einsteins Relativitätstheorie. Wolfenbüttel: Heckner. Friedlaender, Salomo (1932/2005). "Kant gegen Einstein". In Geerken, Hartmut & Thiel, Detlef (ed.). Gesammelte Schriften. Books on Demand. ISBN 978-3-8370-0052-8. {{cite book}}: Check date values in: |year= (help)CS1 maint: multiple names: editors list (link) Gehrcke, Ernst (1916). "Zur Kritik und Geschichte der neueren Gravitationstheorien". Annalen der Physik. 356 (17): 119–124. doi:10.1002/andp.19163561704. Gehrcke, Ernst (1924a). Kritik der Relativitätstheorie : Gesammelte Schriften über absolute und relative Bewegung. Berlin: Meusser. Gehrcke, Ernst (1924b). Die Massensuggestion der Relativitätstheorie: Kulturhistorisch-psychologische Dokumente. Berlin: Meuser. Israel, Hans; Ruckhaber, Erich; Weinmann, Rudolf, ed. (1931). Hundert Autoren gegen Einstein. Leipzig: Voigtländer.{{cite book}}: CS1 maint: multiple names: editors list (link). Ives, Herbert E. (1951). "Revisions of the Lorentz transformation". Proceedings of the American Philosophical Society. 95 (2): 125–131. Kaufmann, Walter (1906). "Über die Konstitution des Elektrons". Annalen der Physik. 324 (3): 487–553. Kraus, Oskar (1921). "Fiktion und Hypothese in der Einsteinschen Relativitätstheorie. Erkenntnistheoretische Betrachtungen". Annalen der Philosophie. 2 (3): 335–396. Lenard, Philipp (1921a). Über Relativitätsprinzip, Äther, Gravitation (3. vermehrte Auflage). Leipzig: Hirzel. Lenard, Philipp. (Hrsg.) (1921b). "Vorbemerkung zu Soldners „Über die Ablenkung eines Lichtstrahls von seiner geradlinigen Bewegung durch die Attraktion eines Weltkörpers, an welchem er nahe vorbeigeht";". Annalen der Physik. 370 (15): 593–604. doi:10.1002/andp.19213701503. Lenard, Philipp (1936). Deutsche Physik. Vol. Bd. 1. München: J.F. Lehmann. Linke, Paul F. (1921). "Relativitätstheorie und Relativismus. Betrachtungen über Relativitätstheorie, Logik und Phänomenologie". Annalen der Philosophie. 2 (3): 397–438. Lodge, Oliver (1925/2003). Ether and Reality. Whitefish: Kessinger. ISBN 076617865X. {{cite book}}: Check date values in: |year= (help) Mewes, Rudolf (1920). Wissenschaftliche Begründung der Raumzeitlehre oder Relativitätstheorie (1884-1894) mit einem geschichtlichen Anhang. Berlin: Mewes. Michelson, Albert Abraham (1927). Studies in Optics. Chicago: University Press. p. 155. Miller, Dayton C. (1933). "The Ether-Drift Experiment and the Determination of the Absolute Motion of the Earth". Reviews of Modern Physics. 5: 203–242. doi:10.1103/RevModPhys.5.203. {{cite journal}}: Unknown parameter |ussue= ignored (help) Mohorovičić, Stjepan (1923). Die Einsteinsche Relativitätstheorie und ihr mathematischer, physikalischer und philosophischer Charakter. Berlin: de Gruyter. Natorp, Paul (1910). "Das Relativitätsprinzip etc.". Die logischen Grundlagen der exakten Wissenschaften. Leipzig & Berlin: B.G. Teubner. pp. 392–404. Patschke, Arthur (1922). Umsturz der Einsteinschen Relativitätstheorie. Berlin-Wilmersdorf: Patschke. Poincaré, Henri (1904/6). "Der gegenwärtige Zustand und die Zukunft der mathematischen Physik" . Der Wert der Wissenschaft (Kap. 7-9). Leipzig: B.G. Teubner. pp. 129–159. {{cite book}}: Check date values in: |year= (help). (This paper is only partly to be considered as critical, since the question after the validity of the relativity principle remained undecided. It was Poincaré himself, who solved many problems in 1905.) Prokhovnik, Simon Jacques (1963). The Case for an Aether. Vol. 14. pp. 195–207. {{cite book}}: |journal= ignored (help) Reuterdahl, Arvid (1920). Scientific theism versus materialism. The space-time potential. New York: Devin-Adair. Ritz, Walter (1908). Recherches critiques sur l'Électrodynamique Générale. Vol. 13. pp. 145–275. {{cite book}}: |journal= ignored (help) Siehe auch englische Übersetzung. Stark, Johannes & Müller, Wilhelm (1941). Jüdische und Deutsche Physik. {{cite book}}: |journal= ignored (help)CS1 maint: multiple names: authors list (link) Thüring, Bruno (1941). Albert Einsteins Umsturzversuch der Physik und seine inneren Möglichkeiten und Ursachen. Vol. 4. pp. 134–162. {{cite book}}: |journal= ignored (help) Ziegler, Johann Heinrich ( 1857-1936 ) (1920). "Das Ding an sich" und das Ende der sog. Relativitätstheorie. Zürich: Weltformel-Verlag.{{cite book}}: CS1 maint: numeric names: authors list (link)

External links

• The Newspaper clippings and works collected by Gehrcke and Reuterdahl form an important basis for historic research on the criticism of relativity;

• The Ernst Gehrcke Papers. Over 2700 newspaper articles collected by Gehrcke, digitized at the MPIWG.
• Arvid Reuterdahl Papers, digizied by the University of St. Thomas Libraries, which are online accessible.

• Milena Wazeck: Einstein's sceptics: Who were the relativity deniers?], New Scientist, 18 November 2010.