Criticism of relativity theory
Encyclopedia
Criticism of Albert Einstein
's theory of relativity
was mainly expressed in the early years after its publication on a scientific
, pseudoscientific
, philosophical
, or 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. Even 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
.
(1897) and Wilhelm Wien
(1900). This was apparently confirmed by the experiments of Walter Kaufmann
(1901–1903), who measured an increase of the mass of a body with velocity which was consistent with the hypothesis that the mass was generated by its electromagnetic field. Max Abraham
(1902) subsequently sketched a theoretical explanation of Kaufmann's result in which the electron was considered as rigid and spherical. However, it was found that this model was incompatible with the results of many experiments (including the Michelson-Morley experiment
, the Experiments of Rayleigh and Brace
, and the Trouton-Noble experiment
), according to which no absolute motion of an observer with respect to the luminiferous aether
("aether drift") could be observed. Henri Poincaré
(1902) called this impossibility "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 of which are part of the Lorentz transformation
.Miller (1981), pp. 47-75Lorentz (1904)
Against Lorentz, Abraham (1904) said 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 he doubted the possibility that (b) a model based on the relativity principle could be formulated at all. However, Poincaré (1905/6) could show that (b) is possible 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.Miller (1981), pp. 75-85Darrigol (2000), pp. 372-392Janssen (2007), pp. 25-34Poincaré (1906)Einstein (1905)Abraham (1904)
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 was still evaluating 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 require rejection of the "basic assumption of Lorentz and Einstein" (the relativity principle). Lorentz reacted with the phrase "I am at the end of my Latin", while Einstein did not mention those experiments 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 cast 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 Bucherer's experiments were criticized by Bestelmeyer leading to a sharp dispute between the two 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 accelerator
s, the relativistic mass formula is routinely confirmed.)Pauli (1921), pp. 636-637Pauli (1981), pp. 334-352Staley (2009), pp. 219-259Planck (1906b)Bucherer (1908)Kaufmann (1906)
In 1902-1906, Dayton Miller
repeated the Michelson-Morley experiment together with Edward Williams Morley. They confirmed the null 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
pointed out that Miller hadn't appropriately considered the influence of temperature. And a modern analysis by Roberts shows, that Miller's experiment gives a null result, when the technical shortcomings of the apparatus and the error bars are properly considered. Additionally, Miller's result is in disagreement with all other experiments, which were conducted before and after. For example, Georg Joos
(1930) used an apparatus of similar dimensions to Miller's, but he obtained null results. And in recent experiments of Michelson-Morley type where the coherence length
is increased considerably by using laser
s and maser
s the results are still negative.Swenson (1970), pp. 63-68Roberts (2006)Miller (1933)
, Rindler coordinates
, Born coordinates
). Paradoxes relying on insufficient understanding of these facts were discovered in the early years of relativity. For example, Max Born
(1909) tried to combine the concept of rigid bodies with special relativity. That this model was insufficient 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
). And Max von Laue
(1911) showed 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.Pauli (1920), pp. 689-691Born (1909)Laue (1911)Ehrenfest (1909)
Paul Langevin
and von Laue showed that the twin paradox
can be completely resolved 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 reference and therefore his assessment of which events are simultaneous changed during the acceleration. For the other twin nothing changes since he remained in a single frame.Laue (1921a), pp. 59, 75-76Langevin (1911)
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 had proved the existence of the aether. However, special relativity can easily explain this effect. 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 one 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.Laue (1921a), pp. 25-26, 128-130Langevin (1921)
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 with the Equivalence principle
. Einstein was also unsatisfied with the fact that inertial frames are preferred over accelerated frames. Thus over 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 conclusion that (like in accelerated frames) the speed of light is not constant in extended gravitational fields. Therefore, Abraham (1912) argued that Einstein had given special relativity a coup de grâce
. Einstein responded that within its area of application (in areas where gravitational influences can be neglected) special relativity is still applicable with high precision, so one cannot speak of a coup de grâce at all.Pais (1982), pp. 177-207, 230-232Einstein (1908)Einstein (1912)Einstein (1916)Abraham (1912)
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
.
Poincaré (1906)
Carlip (1999)
Poincaré (1904)
Another apparent contradiction lies in the fact, that the group velocity
in anomalously 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 Günter Nimtz
can be explained by a thorough consideration of the velocities involved.
Pauli (1921), 672-673
PhysicsFaq: FTL
Sommerfeld (1907, 1914)
Brillouin (1914)
Also quantum entanglement
(denoted by Einstein as "spooky action at a distance"), according to which the quantum state of one entangled particle cannot be fully described without describing the other particle, does not imply superluminal transmission of information (see quantum teleportation
), and it is therefore in conformity with special relativity.
PhysicsFaq: FTL
and time dilation
, led and still leads to the construction of various apparent paradox
es. 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 1950s. However, also the self-consistency of the reciprocity of time dilation was already demonstrated long before in an illustrative way by Lorentz (in his lectures from 1910, published 1931)Miller (1981), pp. 257-264 and many others - they alluded to the fact, that 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.
Chang (1993)
Mathpages: Dingle
Dingle (1972)
, 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.
Miller (1983), pp. 216-2717
Warwick (2003), pp. 410-419, 469-475
Paty (1987), pp. 145-147
Planck (1906ab)
Lodge (1925)
Michelson (1927)
Ives (1951)
Prokhovnik (1963)
Another attempt to re-establish some sort of ether was made by Einstein in some semi-popular papers in the 1920s. This was concluded by him as a consequence of the fact, that the space-time continuum of special relativity cannot be influenced by the presence of matter and, as the aether or Newton's absolute space, consequently has an independent existence. Einstein argued, that this is partly also the case in general relativity
as a consequence of the failure of Mach's principle
, although contrary to Newton's absolute space, the "ether of general relativity" is affected by the presence of matter (see section on General covariance below). 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
(1951) 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 (2006) 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.
Kragh (1990), pp. 189-205
Smoot (2006)
Dirac (1951)
, as proposed by George Gabriel Stokes
(1844), was used by some critics as Ludwig Silberstein (1920) or Philipp Lenard
(1920) 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.
Joos (1959), pp. 448ff
Michelson (1925)
Lenard (1921a)
Silberstein (1921a)
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 star
s 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.
Norton (2004), pp. 14-22
DeSitter (1913)
Fox (1965)
Ritz (1908)
). However, as already shown by Robert Daniel Carmichael
(1910) and others, the constancy of the speed of light can be interpreted as a natural consequence of two experimentally demonstrated facts:Hentschel (1990), pp. 343-348.
Carmichael (1910)
Note, that measurements regarding the speed of light are actually measurements of the two-way speed of light, since the one-way speed of light depends on which convention is chosen to synchronize the clocks
.
for the development of general relativity. This view was challenged by Erich Kretschmann
(1917), who argued that every theory of space and time (even including Newtonian dynamics) can be formulated in a covariant way, if additional parameters are included - so stating general covariance as the basis of a theory would be insufficient. Although Einstein (1918) agreed with that argument, he argued that Newtonian mechanics in general covariant form would be too complicated for practical uses. Although Einstein's answer was incorrect (subsequent papers showed that such a theory would still be usable), there can be made another argument in favor of general covariance: it is a natural way to express the equivalence principle
, i.e., the equivalence in the description of a free-falling observer and an observer at rest, and thus it is near at hand to use general covariance together with general relativity, not with Newtonian mechanics. Connected with this, also the question of absolute motion was dealt with. Einstein argued, that general covariance is connected with Mach's principle
, which would eliminate any "absolute motion" within general relativity. Yet, as pointed out by Willem de Sitter
in 1916, Mach's principle is not fulfilled in general relativity because matter-free solutions of the field equations are possible as well. This means that the "inertio-gravitational field", which describes both gravity and inertia, can also exist without matter (therefore Einstein for some time used the term "ether" for this field in some semi-popular lectures). However, as pointed out by Einstein, there is a fundamental difference: while Newton's absolute space is strictly separated from matter, the inertio-gravitational field of general relativity can also be influenced by matter.
Janssen (2008), pp. 3-4, 17-18, 28-38
Norton (1993)
Einstein (1916)
DeSitter (1916ab)
Kretschmann (1917)
Einstein (1920, 1924)
, the latter stated the following objections: He criticized the lack of "illustrativeness" of relativity, a condition that allegedly can only be met by an aether theory. Einstein responded that the content of "illustrativeness" or "common sense
" has changed in time, so it cannot be used as a criterion for the validity of a theory. Lenard also argued, that Einstein reintroduced the aether in general relativity. This was refuted by Hermann Weyl
- although Einstein used that expression in 1920, he simply referred to the fact that in general relativity, space possesses properties that influences matter and vice versa. However, no "substance" with a state motion (as the aether in the older sense) exists in general relativity. Lenard also argued, that general relativity admits of the existence of superluminal velocities. For example, in a reference frame in which the Earth is at rest, the distant points of the whole universe are rotating around Earth with superluminal velocities. However, as been pointed out by Weyl, it's not possible to handle a rotating extended system as a rigid body (neither in special nor in general relativity) - so the signal velocity
of an object never exceeds the speed of light. Another issue (that was raised by both Lenard and Gustav Mie
) concerns the existence of "fictitious" gravitational fields, which were introduced by Einstein within accelerated frames to guarantee their equivalence to frames in which gravitational fields exist. Lenard and Mie argued, that only forces can exist that are proportional to real existing masses, while the gravitational field in an accelerating frame of reference has no physical meaning, i.e. the relativity principle can only be valid for mass proportional forces. Einstein responded, that based on Mach's principle
one can think of these gravitational fields as induced by the distant masses. In this respect the criticism of Lenard and Mie was partly justified - Mach's principle is not fulfilled in general relativity, as already mentioned above.
Goenner (1993a), pp. 124-128
Lenard, Einstein, Gehrcke, Weyl (1920)
, who initially was a supporter of the special theory, objected at different occasions against general relativity. In 1920 he argued that the deflection of light by the sun, as observed by Arthur Eddington et al. (1919), is not necessarily a confirmation of general relativity, but may also be explained by the Stokes-Planck theory of complete aether drag. However, such models are in contradiction with the aberration of light
and other experiments (see "Alternative theories"). And in 1935, Silberstein claimed to have found a contradiction in the Two-body problem in general relativity. However, also this claim was refuted by Einstein and Rosen (1935).
Havas (1993), pp. 97-120
Einstein/Rosen (1936)
Silberstein (1936)
. 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 reportedly used expressions like "absolute theory") sympathized with this expression as well.
Hentschel (1990), pp. 92-105, 401-419
Klein (1910)
Petzoldt (1921)
Planck (1925)
Critical responses to relativity (in German speaking countries) were also expressed by proponents of Neo-Kantianism
(Paul Natorp
, Bruno Bauch
, etc.), and Phenomenology (Oskar Becker
, Moritz Geiger
etc.). 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 of space and time. Also the three-dimensionality of space, Euclidean geometry, and the existence of absolute simultaneity was claimed to be necessary for the understanding of the world - none of them can possibly be altered by empirical findings. However, Hentschel (1990) and others criticized these arguments as "Strategies of Immunization". By moving all those concepts into a metaphysical area, 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 thoughts. Therefore, 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
.
Hentschel (1990), pp. 199-239, 254-268, 507-526
Reichenbach (1920)
Cassirer (1921)
Natorp (1910)
Linke (1921)
Friedlaender (1932)
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 hypotheses. On the other hand, relativity doesn't need such hypotheses, thus from a conceptual viewpoint, relativity is in fact more simple than Newtonian mechanics.
Hentschel (1990), pp. 293-336
Schlick (1921)
Reichenbach (1924)
Dingler (1922)
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.
Hentschel (1990), pp. 240-243, 441-455
Metz (1923)
Bergson (1921)
Based on the philosophy of Fictionalism
, the philosopher Oskar Kraus
(1921) and others claimed that the foundations of relativity were only fictitious and even self-contradictory. Examples were the constancy of the speed of light, time dilation, length contraction. These effects appear to be mathematically consistent as a whole, but in reality they allegedly are not true. Yet, this view was immediately rejected. The foundations of relativity (such as 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.
Hentschel (1990), pp. 276-292
Kraus (1921)
In the Soviet Union
(mostly in the 1920s), 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
)
Vizgin/Gorelik (1987), pp. 265-326
Hu (2007), 549-555
, 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 (atypical 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.
Goenner (1993a)
Wazeck (2009)
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 mechanics
. 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.
Hentschel (1990), pp. 74-91
Gehrcke (1924a)
Mohorovičić (1923)
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", such as Arvid Reuterdahl, Hermann Fricke or Johann Heinrich Ziegler). 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.
Wazeck (2009), pp. 27-84
Fricke (1919)
Ziegler (1920)
Reuterdahl (1921)
Since Einstein rarely defended himself against these attacks, this task was undertaken 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 believe that this was due to their incorrect theories, but rather due to a conspiracy
of the relativistic physicists (and in the 1920s & 1930s 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.
Hentschel (1990), pp. 163-195
Wazeck (2009), pp. 113-193, 217-292
Gehrcke (1924b)
Afterward, some critics tried to improve their positions by the formation of alliances
. One of them was the "Academy 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 1920s in Germany and 1930 in the USA.
Wazeck (2009), pp. 293-378
, there appeared some nationalistically motivated criticisms 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.
Hentschel (1990), pp. 123-131
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 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 mood, Einstein openly speculated in a newspaper article that, in addition to insufficient knowledge of theoretical physics, antisemitism was also a reason 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, subsequently 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 unhindered. After the murder of Walther Rathenau
(1922) and murder threats against Einstein, he left Berlin for some time. Gehrcke's book on "The mass suggestion of relativity theory" (1924) was not antisemitic itself, but it was praised by the far-right press as describing an alleged typical Jewish behavior. Philipp Lenard
in 1922 spoke about the "foreign spirit" as the foundation of relativity, and afterward he joined the Nazi party in 1924; Johannes Stark
did the same in 1930. Both were proponents of the so-called German Physics
, which only accepted scientific knowledge based on experiments, and only if accessible to the senses. According to Lenard (1936), this is the "Aryan 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 made comparisons between the Talmud
and relativity.
Kleinert (1979)
Beyerchen (1982)
Hentschel (1990), pp. 131-150
Posch (2006)
Wazeck (2009), pp. 271-392
Einstein (1920a)
Lenard (1936)
Stark/Müller (1941)
Thüring (1941)
Hentschel (1990), pp. 150-162
Wazeck (2009), pp. 194-216
Laue (1917)
Laue (1921b)
Gehrcke (1916)
Lenard (1921b)
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.Darrigol (2004) Another discussion concerns a possible mutual influence between Einstein and David Hilbert
as regards completing the field equations
of general relativity (see Relativity priority dispute
).
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.
"If I were wrong, it would only have taken one." --Albert Einstein, commenting on the book 100 Authors Against Einstein
According to Goenner, the contributions to the book are a mixture of mathematical-physical incompetence, hubris
, 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 know 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 two persons were substantially younger. Two authors (Reuterdahl, von Mitis) were antisemitic 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, Emanuel Lasker
, Oskar Kraus
, Menyhért Palágyi
).
Goenner (1993b)
Wazeck (2009), pp. 356-361
Israel et al. (1931)
. Therefore, fundamental criticism (like those of Herbert Dingle
, Louis Essen
, Petr Beckmann
, Maurice Allais
, Tom van Flandern
) have not been taken serious by the scientific community, and due to the lack of quality of many critical publications (found in the process of Peer review
) they were rarely accepted for publication in reputable scientific journals. So, as in the 1920s, most of the critical works have been published in small publications houses, alternative journals (like "Apeiron" or "Galilean Electrodynamics"), or private websites (like Conservapedia
).Newscientist and Cosmosmagazine Consequently, where criticism of relativity has been dealt with by the scientific community, it has mostly been in historical studies.
Hentschel (1990)
Wazeck (2009)
However, this does not mean that there is no further development in modern physics. The enormous progress of technologies leads to extremely precise ways to test the predictions of relativity, and so far it successfully passed all tests (such as in particle accelerators to test special relativity, and by astronomical observations to test general relativity). 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.
Mattingly (2005)
Will (2006)
Liberati (2009)
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
's theory of relativity
Theory of relativity
The theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity. However, the word relativity is sometimes used in reference to Galilean invariance....
was mainly expressed in the early years after its publication on a scientific
Science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...
, pseudoscientific
Pseudoscience
Pseudoscience is a claim, belief, or practice which is presented as scientific, but which does not adhere to a valid scientific method, lacks supporting evidence or plausibility, cannot be reliably tested, or otherwise lacks scientific status...
, philosophical
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
, or ideological
Ideology
An ideology is a set of ideas that constitutes one's goals, expectations, and actions. An ideology can be thought of as a comprehensive vision, as a way of looking at things , as in common sense and several philosophical tendencies , or a set of ideas proposed by the dominant class of a society to...
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. Even 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
Quantum electrodynamics
Quantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...
.
Relativity principle versus electromagnetic worldview
Around the turn of the century, the view was widespread that all forces in nature are of electromagnetic origin (the "electromagnetic worldview"), especially in the works of Joseph LarmorJoseph Larmor
Sir Joseph Larmor , a physicist and mathematician who made innovations in the understanding of electricity, dynamics, thermodynamics, and the electron theory of matter...
(1897) and Wilhelm Wien
Wilhelm Wien
Wilhelm Carl Werner Otto Fritz Franz Wien was a German physicist who, in 1893, used theories about heat and electromagnetism to deduce Wien's displacement law, which calculates the emission of a blackbody at any temperature from the emission at any one reference temperature.He also formulated an...
(1900). This was apparently confirmed by the experiments of Walter Kaufmann
Walter Kaufmann (physicist)
Walter Kaufmann was a German physicist. He is most well known for his first experimental proof of the velocity dependence of mass, which was an important contribution to the development of modern physics, including special relativity.-Life:In 1890/91 he studied mechanical engineering at the...
(1901–1903), who measured an increase of the mass of a body with velocity which was consistent with the hypothesis that the mass was generated by its electromagnetic field. Max Abraham
Max Abraham
Max Abraham was a German physicist.Abraham was born in Danzig, Imperial Germany to a family of Jewish merchants. His father was Moritz Abraham and his mother was Selma Moritzsohn. Attending the University of Berlin, he studied under Max Planck. He graduated in 1897...
(1902) subsequently sketched a theoretical explanation of Kaufmann's result in which the electron was considered as rigid and spherical. However, it was found that this model was incompatible with the results of many experiments (including the Michelson-Morley experiment
Michelson-Morley experiment
The Michelson–Morley experiment was performed in 1887 by Albert Michelson and Edward Morley at what is now Case Western Reserve University in Cleveland, Ohio. Its results are generally considered to be the first strong evidence against the theory of a luminiferous ether and in favor of special...
, the Experiments of Rayleigh and Brace
Experiments of Rayleigh and Brace
The experiments of Rayleigh and Brace were aimed to show whether length contraction leads to birefringence or not. They were some of the first optical experiments measuring the relative motion of Earth and the luminiferous aether which were sufficiently precise to detect magnitudes of second order...
, and the Trouton-Noble experiment
Trouton-Noble experiment
The Trouton–Noble experiment attempted to detect motion of the Earth through the luminiferous aether, and was conducted in 1901–1903 by Frederick Thomas Trouton and H. R. Noble...
), according to which no absolute motion of an observer with respect to the luminiferous aether
Luminiferous aether
In the late 19th century, luminiferous aether or ether, meaning light-bearing aether, was the term used to describe a medium for the propagation of light....
("aether drift") could be observed. Henri Poincaré
Henri Poincaré
Jules Henri Poincaré was a French mathematician, theoretical physicist, engineer, and a philosopher of science...
(1902) called this impossibility "the principle of relativity
Principle of relativity
In physics, the principle of relativity is the requirement that the equations describing the laws of physics have the same form in all admissible frames of reference....
". Therefore Hendrik Antoon Lorentz (1904) created a model (Lorentz ether theory
Lorentz ether theory
What is now often called Lorentz Ether theory has its roots in Hendrik Lorentz's "Theory of electrons", which was the final point in the development of the classical aether theories at the end of the 19th and at the beginning of the 20th century....
) that was based on an immobile aether, and contrary to the theory of Abraham, it included effects like length contraction
Length contraction
In physics, length contraction – according to Hendrik Lorentz – is the physical phenomenon of a decrease in length detected by an observer of objects that travel at any non-zero velocity relative to that observer...
and local time
Relativity of simultaneity
In physics, the relativity of simultaneity is the concept that simultaneity–whether two events occur at the same time–is not absolute, but depends on the observer's reference frame. According to the special theory of relativity, it is impossible to say in an absolute sense whether two events occur...
both of which are part of the Lorentz transformation
Lorentz transformation
In physics, the Lorentz transformation or Lorentz-Fitzgerald transformation describes how, according to the theory of special relativity, two observers' varying measurements of space and time can be converted into each other's frames of reference. It is named after the Dutch physicist Hendrik...
.Miller (1981), pp. 47-75Lorentz (1904)
Against Lorentz, Abraham (1904) said 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 he doubted the possibility that (b) a model based on the relativity principle could be formulated at all. However, Poincaré (1905/6) could show that (b) is possible when a non-electric potential ("Poincaré stress
Magnetic potential
The term magnetic potential can be used for either of two quantities in classical electromagnetism: the magnetic vector potential, A, and the magnetic scalar potential, ψ...
") 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
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
published in September 1905 what is now called special relativity
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
, 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.Miller (1981), pp. 75-85Darrigol (2000), pp. 372-392Janssen (2007), pp. 25-34Poincaré (1906)Einstein (1905)Abraham (1904)
Experimental refutations
To conclusively decide between the theories of Abraham and Lorentz, Kaufmann repeated his experiments in 1905 with improved accuracy. However, in the meantime the theoretical situation had changed. Alfred BuchererAlfred Bucherer
Alfred Heinrich Bucherer was a German physicist, who is known for his experiments on relativistic mass...
and Paul Langevin
Paul Langevin
Paul Langevin was a prominent French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the Comité de vigilance des intellectuels antifascistes, an antifascist organization created in the wake of the 6 February 1934 far right riots...
(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 was still evaluating 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 require rejection of the "basic assumption of Lorentz and Einstein" (the relativity principle). Lorentz reacted with the phrase "I am at the end of my Latin", while Einstein did not mention those experiments before 1908. Yet, others started to criticize the experiments. Max Planck
Max Planck
Max Karl Ernst Ludwig Planck, ForMemRS, was a German physicist who actualized the quantum physics, initiating a revolution in natural science and philosophy. He is regarded as the founder of the quantum theory, for which he received the Nobel Prize in Physics in 1918.-Life and career:Planck came...
(1906) alluded to inconsistencies in the theoretical interpretation of the data, and Adolf Bestelmeyer
Adolf Bestelmeyer
Adolf Bestelmeyer was a German experimental physicist.-Life and work:...
(1906) introduced new techniques, which (especially in the area of low velocities) gave different results and which cast 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 Bucherer's experiments were criticized by Bestelmeyer leading to a sharp dispute between the two 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 accelerator
Particle accelerator
A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...
s, the relativistic mass formula is routinely confirmed.)Pauli (1921), pp. 636-637Pauli (1981), pp. 334-352Staley (2009), pp. 219-259Planck (1906b)Bucherer (1908)Kaufmann (1906)
In 1902-1906, Dayton Miller
Dayton Miller
Dayton Clarence Miller was an American physicist, astronomer, acoustician, and accomplished amateur flautist...
repeated the Michelson-Morley experiment together with Edward Williams Morley. They confirmed the null result
Null result
In science, a null result is a result without the expected content: that is, the proposed result is absent. It is an experimental outcome which does not show an otherwise expected effect. This does not imply a result of zero or nothing, simply a result that does not support the hypothesis...
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
Max Born
Max Born was a German-born physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s...
, and Robert S. Shankland
Robert S. Shankland
Robert Sherwood Shankland was an American physicist and historian.-Biography:Robert S. Shankland was an undergraduate at the Case School for Applied Sciences from 1925–1929 and received his master's degree in 1933. He completed his Ph.D. degree in 1935 for work on photon scattering with Arthur...
pointed out that Miller hadn't appropriately considered the influence of temperature. And a modern analysis by Roberts shows, that Miller's experiment gives a null result, when the technical shortcomings of the apparatus and the error bars are properly considered. Additionally, Miller's result is in disagreement with all other experiments, which were conducted before and after. For example, Georg Joos
Georg Joos
Georg Jakob Christof Joos was a German theoretical physicist. He wrote Lehrbuch der theoretischen Physik, first published in 1932 and one of the most influential theoretical physics textbooks of the 20th Century.-Education:Joos began his higher education in 1912 at the Technische Hochschule...
(1930) used an apparatus of similar dimensions to Miller's, but he obtained null results. And in recent experiments of Michelson-Morley type where the coherence length
Coherence length
In physics, coherence length is the propagation distance from a coherent source to a point where an electromagnetic wave maintains a specified degree of coherence. The significance is that interference will be strong within a coherence length of the source, but not beyond it...
is increased considerably by using laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
s and maser
Maser
A maser is a device that produces coherent electromagnetic waves through amplification by stimulated emission. Historically, “maser” derives from the original, upper-case acronym MASER, which stands for "Microwave Amplification by Stimulated Emission of Radiation"...
s the results are still negative.Swenson (1970), pp. 63-68Roberts (2006)Miller (1933)
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 acceleration actually can be described in the framework of special relativity (see Hyperbolic motionHyperbolic motion (relativity)
Hyperbolic motion is the motion of an object with constant proper acceleration in special relativity. It is called hyperbolic motion because the equation describing the path of the object through spacetime is a hyperbola, as can be seen when graphed on a Minkowski diagram.The proper acceleration...
, Rindler coordinates
Rindler coordinates
In relativistic physics, the Rindler coordinate chart is an important and useful coordinate chart representing part of flat spacetime, also called the Minkowski vacuum. The Rindler chart was introduced by Wolfgang Rindler. The Rindler coordinate system or frame describes a uniformly accelerating...
, Born coordinates
Born coordinates
In relativistic physics, the Born coordinate chart is a coordinate chart for Minkowski spacetime, the flat spacetime of special relativity. It is often used to analyze the physical experience of observers who ride on a ring or disk rigidly rotating at relativistic speeds...
). Paradoxes relying on insufficient understanding of these facts were discovered in the early years of relativity. For example, Max Born
Max Born
Max Born was a German-born physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s...
(1909) tried to combine the concept of rigid bodies with special relativity. That this model was insufficient was shown by Paul Ehrenfest
Paul Ehrenfest
Paul Ehrenfest was an Austrian and Dutch physicist, who made major contributions to the field of statistical mechanics and its relations with quantum mechanics, including the theory of phase transition and the Ehrenfest theorem.- Biography :Paul Ehrenfest was born and grew up in Vienna in a Jewish...
(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
Ehrenfest paradox
The Ehrenfest paradox concerns the rotation of a "rigid" disc in the theory of relativity.In its original formulation as presented by Paul Ehrenfest 1909 in the Physikalische Zeitschrift, it discusses an ideally rigid cylinder that is made to rotate about its axis of symmetry...
). And Max von Laue
Max von Laue
Max Theodor Felix von Laue was a German physicist who won the Nobel Prize in Physics in 1914 for his discovery of the diffraction of X-rays by crystals...
(1911) showed 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.Pauli (1920), pp. 689-691Born (1909)Laue (1911)Ehrenfest (1909)
Paul Langevin
Paul Langevin
Paul Langevin was a prominent French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the Comité de vigilance des intellectuels antifascistes, an antifascist organization created in the wake of the 6 February 1934 far right riots...
and von Laue showed that the twin paradox
Twin paradox
In physics, the twin paradox is a thought experiment in special relativity, in which a twin makes a journey into space in a high-speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth...
can be completely resolved 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 reference and therefore his assessment of which events are simultaneous changed during the acceleration. For the other twin nothing changes since he remained in a single frame.Laue (1921a), pp. 59, 75-76Langevin (1911)
Another example is the Sagnac effect
Sagnac effect
The Sagnac effect , named after French physicist Georges Sagnac, is a phenomenon encountered in interferometry that is elicited by rotation. The Sagnac effect manifests itself in a setup called ring interferometry. A beam of light is split and the two beams are made to follow a trajectory in...
. 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 had proved the existence of the aether. However, special relativity can easily explain this effect. 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 one 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.Laue (1921a), pp. 25-26, 128-130Langevin (1921)
As it was shown by Einstein, the only form of accelerated motion that cannot be described is the one due to gravitation
Gravitation
Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...
, since special relativity is not compatible with the Equivalence principle
Equivalence principle
In the physics of general relativity, the equivalence principle is any of several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body is actually...
. Einstein was also unsatisfied with the fact that inertial frames are preferred over accelerated frames. Thus over the course of several years (1908–1915), Einstein developed general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
. This theory includes the replacement of Euclidean geometry
Euclidean geometry
Euclidean geometry is a mathematical system attributed to the Alexandrian Greek mathematician Euclid, which he described in his textbook on geometry: the Elements. Euclid's method consists in assuming a small set of intuitively appealing axioms, and deducing many other propositions from these...
by non-Euclidean geometry
Non-Euclidean geometry
Non-Euclidean geometry is the term used to refer to two specific geometries which are, loosely speaking, obtained by negating the Euclidean parallel postulate, namely hyperbolic and elliptic geometry. This is one term which, for historical reasons, has a meaning in mathematics which is much...
, and the resultant curvature of the path of light led Einstein (1912) to the conclusion that (like in accelerated frames) the speed of light is not constant in extended gravitational fields. Therefore, Abraham (1912) argued that Einstein had given special relativity a coup de grâce
Coup de grâce
The expression coup de grâce means a death blow intended to end the suffering of a wounded creature. The phrase can refer to the killing of civilians or soldiers, friends or enemies, with or without the consent of the sufferer...
. Einstein responded that within its area of application (in areas where gravitational influences can be neglected) special relativity is still applicable with high precision, so one cannot speak of a coup de grâce at all.Pais (1982), pp. 177-207, 230-232Einstein (1908)Einstein (1912)Einstein (1916)Abraham (1912)
Superluminal speeds
In special relativity, the transfer of signals at superluminal speedsFaster-than-light
Faster-than-light communications and travel refer to the propagation of information or matter faster than the speed of light....
is impossible, since this would violate the Poincaré-Einstein synchronization, and the causality
Causality
Causality is the relationship between an event and a second event , where the second event is understood as a consequence of the first....
principle. Following an old argument by Pierre-Simon Laplace
Pierre-Simon Laplace
Pierre-Simon, marquis de Laplace was a French mathematician and astronomer whose work was pivotal to the development of mathematical astronomy and statistics. He summarized and extended the work of his predecessors in his five volume Mécanique Céleste...
, Poincaré (1904) alluded to the fact, that Newton's law of universal gravitation
Newton's law of universal gravitation
Newton's law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them...
is founded on an infinitely great speed of gravity
Speed of gravity
In the context of classical theories of gravitation, the speed of gravity is the speed at which changes in a gravitational field propagate. This is the speed at which a change in the distribution of energy and momentum of matter results in subsequent alteration, at a distance, of the gravitational...
. 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
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
.
Poincaré (1906)
Carlip (1999)
Poincaré (1904)
Another apparent contradiction lies in the fact, that the group velocity
Group velocity
The group velocity of a wave is the velocity with which the overall shape of the wave's amplitudes — known as the modulation or envelope of the wave — propagates through space....
in anomalously dispersive media
Dispersion (optics)
In optics, dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency, or alternatively when the group velocity depends on the frequency.Media having such a property are termed dispersive media...
is higher than the speed of light. This was investigated by Arnold Sommerfeld
Arnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and groomed a large number of students for the new era of theoretical physics...
(1907, 1914) and Léon Brillouin
Léon Brillouin
Léon Nicolas Brillouin was a French physicist. He made contributions to quantum mechanics, radio wave propagation in the atmosphere, solid state physics, and information theory.-Early life:...
(1914). They came to the conclusion that in such cases the signal velocity
Signal velocity
The signal velocity is the speed at which a wave carries information. It describes how quickly a message can be communicated between two separated parties...
is not equal to the group velocity, but to the front velocity
Front velocity
In physics, front velocity is the speed at which the first rise of a pulse above zero moves forward.In mathematics, it is also used to describe the velocity of a possibly propagating front in the solution of hyperbolic partial differential equation....
which is never faster than the speed of light. Similarly, it is also argued that the apparent superluminal effects discovered by Günter Nimtz
Günter Nimtz
Günter Nimtz is a German physicist, working at the 2nd Physics Institute at the University of Cologne in Germany. He has investigated narrow-gap semiconductors and liquid crystals and was engaged in several interdisciplinary studies on the effect of non-ionizing electromagnetic radiation in...
can be explained by a thorough consideration of the velocities involved.
Pauli (1921), 672-673
PhysicsFaq: FTL
Sommerfeld (1907, 1914)
Brillouin (1914)
Also quantum entanglement
Quantum entanglement
Quantum entanglement occurs when electrons, molecules even as large as "buckyballs", photons, etc., interact physically and then become separated; the type of interaction is such that each resulting member of a pair is properly described by the same quantum mechanical description , which is...
(denoted by Einstein as "spooky action at a distance"), according to which the quantum state of one entangled particle cannot be fully described without describing the other particle, does not imply superluminal transmission of information (see quantum teleportation
Quantum teleportation
Quantum teleportation, or entanglement-assisted teleportation, is a process by which a qubit can be transmitted exactly from one location to another, without the qubit being transmitted through the intervening space...
), and it is therefore in conformity with special relativity.
PhysicsFaq: FTL
Paradoxes
Insufficient knowledge of the basics of special relativity, especially the application of the Lorentz transformation in connection with length contractionLength contraction
In physics, length contraction – according to Hendrik Lorentz – is the physical phenomenon of a decrease in length detected by an observer of objects that travel at any non-zero velocity relative to that observer...
and time dilation
Time dilation
In the theory of relativity, time dilation is an observed difference of elapsed time between two events as measured by observers either moving relative to each other or differently situated from gravitational masses. An accurate clock at rest with respect to one observer may be measured to tick at...
, led and still leads to the construction of various apparent paradox
Paradox
Similar to Circular reasoning, A paradox is a seemingly true statement or group of statements that lead to a contradiction or a situation which seems to defy logic or intuition...
es. Both the twin paradox
Twin paradox
In physics, the twin paradox is a thought experiment in special relativity, in which a twin makes a journey into space in a high-speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth...
and the Ehrenfest paradox
Ehrenfest paradox
The Ehrenfest paradox concerns the rotation of a "rigid" disc in the theory of relativity.In its original formulation as presented by Paul Ehrenfest 1909 in the Physikalische Zeitschrift, it discusses an ideally rigid cylinder that is made to rotate about its axis of symmetry...
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
Herbert Dingle
Herbert Dingle , an English physicist and natural philosopher, who served as president of the Royal Astronomical Society from 1951 to 1953, is best known for his opposition to Albert Einstein's special theory of relativity and the protracted controversy that this provoked.-Biography:Dingle was born...
and others. For example, Dingle wrote a series of letter to Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...
at the end of the 1950s. However, also the self-consistency of the reciprocity of time dilation was already demonstrated long before in an illustrative way by Lorentz (in his lectures from 1910, published 1931)Miller (1981), pp. 257-264 and many others - they alluded to the fact, that it is only necessary to carefully consider the relevant measurement rules and the relativity of simultaneity
Relativity of simultaneity
In physics, the relativity of simultaneity is the concept that simultaneity–whether two events occur at the same time–is not absolute, but depends on the observer's reference frame. According to the special theory of relativity, it is impossible to say in an absolute sense whether two events occur...
. Other known paradoxes are the Ladder paradox
Ladder paradox
The ladder paradox is a thought experiment in special relativity. It involves a ladder travelling horizontally and undergoing a length contraction, the result of which being that it can fit into a much smaller garage...
and Bell's spaceship paradox
Bell's spaceship paradox
Bell's spaceship paradox is a thought experiment in special relativity involving accelerated spaceships and strings. The results of this thought experiment are for many people paradoxical. While J. S. Bell's 1976 version of the paradox is the most widely known, it was first designed by E. Dewan and M...
, which also can simply be solved by consideration of the relativity of simultaneity.
Chang (1993)
Mathpages: Dingle
Dingle (1972)
Aether and absolute space
Some physicists (like Oliver Lodge, Albert Abraham MichelsonAlbert Abraham Michelson
Albert Abraham Michelson was an American physicist known for his work on the measurement of the speed of light and especially for the Michelson-Morley experiment. In 1907 he received the Nobel Prize in Physics...
, Edmund Taylor Whittaker, Harry Bateman
Harry Bateman
Harry Bateman FRS was an English mathematician.-Life and work:Harry Bateman first grew to love mathematics at Manchester Grammar School, and in his final year, won a scholarship to Trinity College, Cambridge. There he distinguished himself in 1903 as Senior Wrangler and by winning the Smith's Prize...
, Ebenezer Cunningham
Ebenezer Cunningham
Ebenezer Cunningham was a British mathematician who is remembered for his research and exposition at the dawn of special relativity....
, Charles Émile Picard
Charles Émile Picard
Charles Émile Picard FRS was a French mathematician. He was elected the fifteenth member to occupy seat 1 of the Académie Française in 1924.- Biography :...
, Paul Painlevé
Paul Painlevé
Paul Painlevé was a French mathematician and politician. He served twice as Prime Minister of the Third Republic: 12 September – 13 November 1917 and 17 April – 22 November 1925.-Early life:Painlevé was born in Paris....
, Herbert E. Ives
Herbert E. Ives
Herbert Eugene Ives was a scientist and engineer who headed the development of facsimile and television systems at AT&T in the first half of the twentieth century. He was also a critic of the special theory of relativity, and attempted to disprove the theory by means of logical arguments and...
) 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.
Miller (1983), pp. 216-2717
Warwick (2003), pp. 410-419, 469-475
Paty (1987), pp. 145-147
Planck (1906ab)
Lodge (1925)
Michelson (1927)
Ives (1951)
Prokhovnik (1963)
Another attempt to re-establish some sort of ether was made by Einstein in some semi-popular papers in the 1920s. This was concluded by him as a consequence of the fact, that the space-time continuum of special relativity cannot be influenced by the presence of matter and, as the aether or Newton's absolute space, consequently has an independent existence. Einstein argued, that this is partly also the case in general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
as a consequence of the failure of Mach's principle
Mach's principle
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach....
, although contrary to Newton's absolute space, the "ether of general relativity" is affected by the presence of matter (see section on General covariance below). 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
Paul Dirac
Paul Adrien Maurice Dirac, OM, FRS was an English theoretical physicist who made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics...
(1951) to re-interpret the quantum vacuum as an aether equipped with a state of motion, were not successful. And in his Nobel lecture
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
, George F. Smoot (2006) described his own experiments on Cosmic microwave background radiation
Cosmic microwave background radiation
In cosmology, cosmic microwave background radiation is thermal radiation filling the observable universe almost uniformly....
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
Big Bang
The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...
is most convenient.
Kragh (1990), pp. 189-205
Smoot (2006)
Dirac (1951)
Alternative theories
The theory of complete aether dragAether drag hypothesis
In the 19th century, the theory of the luminiferous aether as the hypothetical medium for the propagation of light was widely discussed. An important part of this discussion was the question concerning the state of motion of Earth with respect to this medium. The aether drag hypothesis dealt with...
, as proposed by George Gabriel Stokes
George Gabriel Stokes
Sir George Gabriel Stokes, 1st Baronet FRS , was an Irish mathematician and physicist, who at Cambridge made important contributions to fluid dynamics , optics, and mathematical physics...
(1844), was used by some critics as Ludwig Silberstein (1920) or Philipp Lenard
Philipp Lenard
Philipp Eduard Anton von Lenard , known in Hungarian as Lénárd Fülöp Eduárd Antal, was a Hungarian - German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties...
(1920) 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
Aberration of light
The aberration of light is an astronomical phenomenon which produces an apparent motion of celestial objects about their real locations...
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.
Joos (1959), pp. 448ff
Michelson (1925)
Lenard (1921a)
Silberstein (1921a)
Another alternative was the so called emission theory
Emission theory
Emission theory was a competing theory for the special theory of relativity, explaining the results of the Michelson-Morley experiment...
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
Galilean transformation
The Galilean transformation is used to transform between the coordinates of two reference frames which differ only by constant relative motion within the constructs of Newtonian physics. This is the passive transformation point of view...
. 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
Sagnac effect
The Sagnac effect , named after French physicist Georges Sagnac, is a phenomenon encountered in interferometry that is elicited by rotation. The Sagnac effect manifests itself in a setup called ring interferometry. A beam of light is split and the two beams are made to follow a trajectory in...
is based on the independence of light speed from the source velocity, and the image of Double star
Double star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
s 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.
Norton (2004), pp. 14-22
DeSitter (1913)
Fox (1965)
Ritz (1908)
Principle of the constancy of the speed of light
Some consider the principle of the constancy of the velocity of light insufficiently substantiated (see One-way speed of lightOne-way speed of light
The "one-way" speed of light from a source to a detector, cannot be measured independently of a convention as to how to synchronize the clocks at the source and the detector. What can however be experimentally measured is the round-trip speed from the source to the detector and back again...
). However, as already shown by Robert Daniel Carmichael
Robert Daniel Carmichael
Robert Daniel Carmichael was a leading American mathematician. Carmichael was born in Goodwater, Alabama. He attended Lineville College, briefly, and he earned his bachelor's degree in 1898, while he was studying towards his Ph.D. degree at Princeton University. Carmichael completed the...
(1910) and others, the constancy of the speed of light can be interpreted as a natural consequence of two experimentally demonstrated facts:Hentschel (1990), pp. 343-348.
Carmichael (1910)
- The velocity of light is independent of the velocity of the source, as demonstrated by De Sitter double star experimentDe Sitter double star experimentThe de Sitter effect was described by de Sitter in 1913 and used to support the special theory of relativity against a competing 1908 emission theory by Walter Ritz that postulated a variable speed of light...
, Sagnac effectSagnac effectThe Sagnac effect , named after French physicist Georges Sagnac, is a phenomenon encountered in interferometry that is elicited by rotation. The Sagnac effect manifests itself in a setup called ring interferometry. A beam of light is split and the two beams are made to follow a trajectory in...
, and many others (see emission theoryEmission theoryEmission theory was a competing theory for the special theory of relativity, explaining the results of the Michelson-Morley experiment...
). - The velocity of light is independent of the direction of velocity of the observer, as demonstrated by Michelson-Morley experimentMichelson-Morley experimentThe Michelson–Morley experiment was performed in 1887 by Albert Michelson and Edward Morley at what is now Case Western Reserve University in Cleveland, Ohio. Its results are generally considered to be the first strong evidence against the theory of a luminiferous ether and in favor of special...
, Kennedy-Thorndike experimentKennedy-Thorndike experimentThe Kennedy–Thorndike experiment first conducted in 1932, is a modified form of the Michelson–Morley experimental procedure, and tests special relativity....
, and many others (see luminiferous aetherLuminiferous aetherIn the late 19th century, luminiferous aether or ether, meaning light-bearing aether, was the term used to describe a medium for the propagation of light....
).
Note, that measurements regarding the speed of light are actually measurements of the two-way speed of light, since the one-way speed of light depends on which convention is chosen to synchronize the clocks
One-way speed of light
The "one-way" speed of light from a source to a detector, cannot be measured independently of a convention as to how to synchronize the clocks at the source and the detector. What can however be experimentally measured is the round-trip speed from the source to the detector and back again...
.
General covariance
Einstein emphasized the importance of general covarianceGeneral covariance
In theoretical physics, general covariance is the invariance of the form of physical laws under arbitrary differentiable coordinate transformations...
for the development of general relativity. This view was challenged by Erich Kretschmann
Erich Kretschmann
Erich Justus Kretschmann was a German physicist.He obtained his D.Phil. at Berlin University in 1914 with his dissertation entitled "Eine Theorie der Schwerkraft im Rahmen der ursprünglichen Einsteinschen Relativitätstheorie "...
(1917), who argued that every theory of space and time (even including Newtonian dynamics) can be formulated in a covariant way, if additional parameters are included - so stating general covariance as the basis of a theory would be insufficient. Although Einstein (1918) agreed with that argument, he argued that Newtonian mechanics in general covariant form would be too complicated for practical uses. Although Einstein's answer was incorrect (subsequent papers showed that such a theory would still be usable), there can be made another argument in favor of general covariance: it is a natural way to express the equivalence principle
Equivalence principle
In the physics of general relativity, the equivalence principle is any of several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body is actually...
, i.e., the equivalence in the description of a free-falling observer and an observer at rest, and thus it is near at hand to use general covariance together with general relativity, not with Newtonian mechanics. Connected with this, also the question of absolute motion was dealt with. Einstein argued, that general covariance is connected with Mach's principle
Mach's principle
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach....
, which would eliminate any "absolute motion" within general relativity. Yet, as pointed out by Willem de Sitter
Willem de Sitter
Willem de Sitter was a Dutch mathematician, physicist and astronomer.-Life and work:Born in Sneek, De Sitter studied mathematics at the University of Groningen and then joined the Groningen astronomical laboratory. He worked at the Cape Observatory in South Africa...
in 1916, Mach's principle is not fulfilled in general relativity because matter-free solutions of the field equations are possible as well. This means that the "inertio-gravitational field", which describes both gravity and inertia, can also exist without matter (therefore Einstein for some time used the term "ether" for this field in some semi-popular lectures). However, as pointed out by Einstein, there is a fundamental difference: while Newton's absolute space is strictly separated from matter, the inertio-gravitational field of general relativity can also be influenced by matter.
Janssen (2008), pp. 3-4, 17-18, 28-38
Norton (1993)
Einstein (1916)
DeSitter (1916ab)
Kretschmann (1917)
Einstein (1920, 1924)
Bad Nauheim Debate
In the "Bad Nauheim Debate" (1920) between Einstein and Philipp LenardPhilipp Lenard
Philipp Eduard Anton von Lenard , known in Hungarian as Lénárd Fülöp Eduárd Antal, was a Hungarian - German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties...
, the latter stated the following objections: He criticized the lack of "illustrativeness" of relativity, a condition that allegedly can only be met by an aether theory. Einstein responded that the content of "illustrativeness" or "common sense
Common sense
Common sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts." Thus, "common sense" equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have...
" has changed in time, so it cannot be used as a criterion for the validity of a theory. Lenard also argued, that Einstein reintroduced the aether in general relativity. This was refuted by Hermann Weyl
Hermann Weyl
Hermann Klaus Hugo Weyl was a German mathematician and theoretical physicist. Although much of his working life was spent in Zürich, Switzerland and then Princeton, he is associated with the University of Göttingen tradition of mathematics, represented by David Hilbert and Hermann Minkowski.His...
- although Einstein used that expression in 1920, he simply referred to the fact that in general relativity, space possesses properties that influences matter and vice versa. However, no "substance" with a state motion (as the aether in the older sense) exists in general relativity. Lenard also argued, that general relativity admits of the existence of superluminal velocities. For example, in a reference frame in which the Earth is at rest, the distant points of the whole universe are rotating around Earth with superluminal velocities. However, as been pointed out by Weyl, it's not possible to handle a rotating extended system as a rigid body (neither in special nor in general relativity) - so the signal velocity
Signal velocity
The signal velocity is the speed at which a wave carries information. It describes how quickly a message can be communicated between two separated parties...
of an object never exceeds the speed of light. Another issue (that was raised by both Lenard and Gustav Mie
Gustav Mie
Gustav Adolf Feodor Wilhelm Ludwig Mie was a German physicist.-Biography:Mie was born in Rostock. From 1886 he studied mathematics and physics at the University of Rostock. In addition to his major subjects, he also attended lectures in chemistry, zoology, geology, mineralogy, astronomy as well as...
) concerns the existence of "fictitious" gravitational fields, which were introduced by Einstein within accelerated frames to guarantee their equivalence to frames in which gravitational fields exist. Lenard and Mie argued, that only forces can exist that are proportional to real existing masses, while the gravitational field in an accelerating frame of reference has no physical meaning, i.e. the relativity principle can only be valid for mass proportional forces. Einstein responded, that based on Mach's principle
Mach's principle
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach....
one can think of these gravitational fields as induced by the distant masses. In this respect the criticism of Lenard and Mie was partly justified - Mach's principle is not fulfilled in general relativity, as already mentioned above.
Goenner (1993a), pp. 124-128
Lenard, Einstein, Gehrcke, Weyl (1920)
Silberstein-Einstein controversy
Ludwik SilbersteinLudwik Silberstein
Ludwik Silberstein was a Polish-American physicist who helped make special relativity and general relativity staples of university coursework...
, who initially was a supporter of the special theory, objected at different occasions against general relativity. In 1920 he argued that the deflection of light by the sun, as observed by Arthur Eddington et al. (1919), is not necessarily a confirmation of general relativity, but may also be explained by the Stokes-Planck theory of complete aether drag. However, such models are in contradiction with the aberration of light
Aberration of light
The aberration of light is an astronomical phenomenon which produces an apparent motion of celestial objects about their real locations...
and other experiments (see "Alternative theories"). And in 1935, Silberstein claimed to have found a contradiction in the Two-body problem in general relativity. However, also this claim was refuted by Einstein and Rosen (1935).
Havas (1993), pp. 97-120
Einstein/Rosen (1936)
Silberstein (1936)
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 relativismRelativism
Relativism is the concept that points of view have no absolute truth or validity, having only relative, subjective value according to differences in perception and consideration....
. 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
Felix Klein
Christian Felix Klein was a German mathematician, known for his work in group theory, function theory, non-Euclidean geometry, and on the connections between geometry and group theory...
(1910) called it the "invariant theory of the Lorentz group" instead of relativity theory, and Einstein (who reportedly used expressions like "absolute theory") sympathized with this expression as well.
Hentschel (1990), pp. 92-105, 401-419
Klein (1910)
Petzoldt (1921)
Planck (1925)
Critical responses to relativity (in German speaking countries) were also expressed by proponents of Neo-Kantianism
Neo-Kantianism
Neo-Kantianism refers broadly to a revived type of philosophy along the lines of that laid down by Immanuel Kant in the 18th century, or more specifically by Schopenhauer's criticism of the Kantian philosophy in his work The World as Will and Representation , as well as by other post-Kantian...
(Paul Natorp
Paul Natorp
Paul Gerhard Natorp was a German philosopher and educationalist, considered one of the co-founders of the Marburg school of neo-Kantianism. He was known as an authority on Plato....
, Bruno Bauch
Bruno Bauch
Bruno Bauch was a German Neo-Kantian philosopher.-Biography:Bauch was born in Groß-Nossen, Münsterberg district, Silesia and studied philosophy in Strasbourg, Heidelberg and Freiburg...
, etc.), and Phenomenology (Oskar Becker
Oskar Becker
Oscar Becker was a German philosopher, logician, mathematician, and historian of mathematics.-Early life:Becker studied mathematics at Leipzig...
, Moritz Geiger
Moritz Geiger
Moritz Geiger was a German philosopher and a disciple of Edmund Husserl. Beside phenomenology, he dedicated himself to psychology, epistemology and aesthetics.- Life :...
etc.). 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
Immanuel Kant
Immanuel Kant was a German philosopher from Königsberg , researching, lecturing and writing on philosophy and anthropology at the end of the 18th Century Enlightenment....
's categoric
Category (Kant)
In Kant's philosophy, a category is a pure concept of the understanding. A Kantian category is a characteristic of the appearance of any object in general, before it has been experienced...
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 of space and time. Also the three-dimensionality of space, Euclidean geometry, and the existence of absolute simultaneity was claimed to be necessary for the understanding of the world - none of them can possibly be altered by empirical findings. However, Hentschel (1990) and others criticized these arguments as "Strategies of Immunization". By moving all those concepts into a metaphysical area, 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 thoughts. Therefore, other Kantians like Ernst Cassirer
Ernst Cassirer
Ernst Cassirer was a German philosopher. He was one of the major figures in the development of philosophical idealism in the first half of the 20th century...
or Hans Reichenbach
Hans Reichenbach
Hans Reichenbach was a leading philosopher of science, educator and proponent of logical empiricism...
(1920), tried to modify Kant's philosophy. Subsequently, Reichenbach rejected Kantianism at all and became a proponent of logical positivism
Logical positivism
Logical positivism is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology.It may be considered as a type of analytic...
.
Hentschel (1990), pp. 199-239, 254-268, 507-526
Reichenbach (1920)
Cassirer (1921)
Natorp (1910)
Linke (1921)
Friedlaender (1932)
Based on Henri Poincaré
Henri Poincaré
Jules Henri Poincaré was a French mathematician, theoretical physicist, engineer, and a philosopher of science...
's conventionalism
Conventionalism
Conventionalism is the philosophical attitude that fundamental principles of a certain kind are grounded on agreements in society, rather than on external reality...
, philosophers such as Pierre Duhem
Pierre Duhem
Pierre Maurice Marie Duhem was a French physicist, mathematician and philosopher of science, best known for his writings on the indeterminacy of experimental criteria and on scientific development in the Middle Ages...
(1914) or Hugo Dingler
Hugo Dingler
Hugo Albert Emil Hermann Dingler . Dingler was a German scientist and philosopher.-Life:...
(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
Logical positivism
Logical positivism is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology.It may be considered as a type of analytic...
such as Moritz Schlick
Moritz Schlick
Friedrich Albert Moritz Schlick was a German philosopher, physicist and the founding father of logical positivism and the Vienna Circle.-Early life and works:...
, Rudolf Carnap
Rudolf Carnap
Rudolf Carnap was an influential German-born philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism....
, 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 hypotheses. On the other hand, relativity doesn't need such hypotheses, thus from a conceptual viewpoint, relativity is in fact more simple than Newtonian mechanics.
Hentschel (1990), pp. 293-336
Schlick (1921)
Reichenbach (1924)
Dingler (1922)
Some proponents of Philosophy of Life
Philosophy of Life
Lebensphilosophie is a philosophical school of thought which emphasises the meaning, value and purpose of life as the foremost focus of philosophy...
, Vitalism
Vitalism
Vitalism, as defined by the Merriam-Webster dictionary, is#a doctrine that the functions of a living organism are due to a vital principle distinct from biochemical reactions...
, Critical realism
Critical realism
In the philosophy of perception, critical realism is the theory that some of our sense-data can and do accurately represent external objects, properties, and events, while other of our sense-data do not accurately represent any external objects, properties, and events...
(in German speaking countries) argued that there is a fundamental difference between physical, biological and psychological phenomena. For example, Henri Bergson
Henri Bergson
Henri-Louis Bergson was a major French philosopher, influential especially in the first half of the 20th century. Bergson convinced many thinkers that immediate experience and intuition are more significant than rationalism and science for understanding reality.He was awarded the 1927 Nobel Prize...
(1921), who otherwise was a proponent of special relativity, argued that time dilation
Time dilation
In the theory of relativity, time dilation is an observed difference of elapsed time between two events as measured by observers either moving relative to each other or differently situated from gravitational masses. An accurate clock at rest with respect to one observer may be measured to tick at...
cannot be applied to biological organisms, therefore he denied the relativistic solution of the twin paradox
Twin paradox
In physics, the twin paradox is a thought experiment in special relativity, in which a twin makes a journey into space in a high-speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth...
. However, those claims were rejected by Paul Langevin
Paul Langevin
Paul Langevin was a prominent French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the Comité de vigilance des intellectuels antifascistes, an antifascist organization created in the wake of the 6 February 1934 far right riots...
, 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.
Hentschel (1990), pp. 240-243, 441-455
Metz (1923)
Bergson (1921)
Based on the philosophy of Fictionalism
Fictionalism
Fictionalism is a methodological theory in philosophy that suggests that statements of a certain sort should not be taken to be literally true, but merely as a useful fiction...
, the philosopher Oskar Kraus
Oskar Kraus
Oskar Kraus was a Czech philosopher, jurist.-Life:Oskar Kraus, who converted from the Jewish to the Protestant faith, was the son of Hermann Kraus and Clara Reitler-Eidlitz...
(1921) and others claimed that the foundations of relativity were only fictitious and even self-contradictory. Examples were the constancy of the speed of light, time dilation, length contraction. These effects appear to be mathematically consistent as a whole, but in reality they allegedly are not true. Yet, this view was immediately rejected. The foundations of relativity (such as 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.
Hentschel (1990), pp. 276-292
Kraus (1921)
In the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
(mostly in the 1920s), 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
Common sense
Common sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts." Thus, "common sense" equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have...
" was required as an alternative. Similar criticisms also occurred in the People's Republic of China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
during the Cultural Revolution
Cultural Revolution
The Great Proletarian Cultural Revolution, commonly known as the Cultural Revolution , was a socio-political movement that took place in the People's Republic of China from 1966 through 1976...
. (On the other hand, other philosophers considered relativity as being compatible with Marxism
Marxism
Marxism is an economic and sociopolitical worldview and method of socioeconomic inquiry that centers upon a materialist interpretation of history, a dialectical view of social change, and an analysis and critique of the development of capitalism. Marxism was pioneered in the early to mid 19th...
)
Vizgin/Gorelik (1987), pp. 265-326
Hu (2007), 549-555
Relativity hype and popular criticism
Although Planck already in 1909 compared the changes brought about by relativity with the Copernican RevolutionCopernican Revolution
The Copernican Revolution refers to the paradigm shift away from the Ptolemaic model of the heavens, which postulated the Earth at the center of the galaxy, towards the heliocentric model with the Sun at the center of our Solar System...
, 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
Arthur Stanley Eddington
Sir Arthur Stanley Eddington, OM, FRS was a British astrophysicist of the early 20th century. He was also a philosopher of science and a popularizer of science...
(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
Johannes Kepler
Johannes Kepler was a German mathematician, astronomer and astrologer. A key figure in the 17th century scientific revolution, he is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican...
and Isaac Newton
Isaac Newton
Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...
. 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 (atypical 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.
Goenner (1993a)
Wazeck (2009)
Academic and non-academic criticism
Some academic scientists, especially experimental physicists such as the Nobel laureates Philipp LenardPhilipp Lenard
Philipp Eduard Anton von Lenard , known in Hungarian as Lénárd Fülöp Eduárd Antal, was a Hungarian - German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties...
and Johannes Stark
Johannes Stark
Johannes Stark was a German physicist, and Physics Nobel Prize laureate who was closely involved with the Deutsche Physik movement under the Nazi regime.-Early years:...
, as well as Ernst Gehrcke
Ernst Gehrcke
Ernst J. L. Gehrcke was a German experimental physicist. He was director of the optical department at the Reich Physical and Technical Institute. Concurrently, he was a professor at the University of Berlin...
, Stjepan Mohorovičić
Stjepan Mohorovicic
Stjepan Mohorovičić was a Croatian scientist born in the town of Bakar and died in the city of Zagreb, Croatia...
, and Rudolf Tomaschek
Rudolf Tomaschek
Rudolf Karl Anton Tomaschek was a German experimental physicist. His scientific efforts included work on phosphorescence, fluorescence, and gravitation. Tomaschek was a supporter of deutsche Physik, which resulted in his suspension from his university posts after World War II...
etc. criticized the increasing mathematization of modern physics, especially in the form of relativity theory and quantum mechanics
Quantum mechanics
Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...
. It was seen as a tendency to abstract theory building, connected with the loss of "common sense
Common sense
Common sense is defined by Merriam-Webster as, "sound and prudent judgment based on a simple perception of the situation or facts." Thus, "common sense" equates to the knowledge and experience which most people already have, or which the person using the term believes that they do or should have...
". 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
Bad Nauheim
Bad Nauheim is a town in the Wetteraukreis district of Hesse state of Germany. , Bad Nauheim has a population of 30,365. The town is located approximately 35 kilometers north of Frankfurt am Main, on the east edge of the Taunus mountain range. It is a world-famous resort, noted for its salt...
debate" in 1920 between Einstein and Lenard, which attracted much attention in the public.
Hentschel (1990), pp. 74-91
Gehrcke (1924a)
Mohorovičić (1923)
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", such as Arvid Reuterdahl, Hermann Fricke or Johann Heinrich Ziegler). Their views had their quite different roots in monism
Monism
Monism is any philosophical view which holds that there is unity in a given field of inquiry. Accordingly, some philosophers may hold that the universe is one rather than dualistic or pluralistic...
, Lebensreform
Lebensreform
Lebensreform was a social movement in late 19th-century and early 20th-century Germany and Switzerland that propagated a back-to-nature lifestyle, emphasizing among others health food/raw food/organic food, nudism, sexual liberation, alternative medicine, and religious reform and at the same time...
, 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
Mechanical explanations of gravitation
Mechanical explanations of gravitation are attempts to explain the action of gravity by aid of basic mechanical processes, such as pressure forces caused by pushes, and without the use of any action at a distance. These theories were developed from the 16th until the 19th century in connection...
, 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.
Wazeck (2009), pp. 27-84
Fricke (1919)
Ziegler (1920)
Reuterdahl (1921)
Since Einstein rarely defended himself against these attacks, this task was undertaken by other relativity theoreticians, who (according to Hentschel) formed some sort of "defensive belt" around Einstein. Some representatives were Max von Laue
Max von Laue
Max Theodor Felix von Laue was a German physicist who won the Nobel Prize in Physics in 1914 for his discovery of the diffraction of X-rays by crystals...
, Max Born
Max Born
Max Born was a German-born physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s...
, etc. and on popular-scientific and philosophical level Hans Reichenbach
Hans Reichenbach
Hans Reichenbach was a leading philosopher of science, educator and proponent of logical empiricism...
, 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 believe that this was due to their incorrect theories, but rather due to a conspiracy
Conspiracy theory
A conspiracy theory explains an event as being the result of an alleged plot by a covert group or organization or, more broadly, the idea that important political, social or economic events are the products of secret plots that are largely unknown to the general public.-Usage:The term "conspiracy...
of the relativistic physicists (and in the 1920s & 1930s 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
Hypnosis
Hypnosis is "a trance state characterized by extreme suggestibility, relaxation and heightened imagination."It is a mental state or imaginative role-enactment . It is usually induced by a procedure known as a hypnotic induction, which is commonly composed of a long series of preliminary...
. Therefore he instructed a Media monitoring service
Media monitoring service
A media monitoring service, a press clipping service or a clipping service as known in earlier times, provides clients with copies of media content, which is of specific interest to them and subject to changing demand; what they provide may include documentation, content, analysis, or editorial...
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.
Hentschel (1990), pp. 163-195
Wazeck (2009), pp. 113-193, 217-292
Gehrcke (1924b)
Afterward, some critics tried to improve their positions by the formation of alliances
Voluntary association
A voluntary association or union is a group of individuals who enter into an agreement as volunteers to form a body to accomplish a purpose.Strictly speaking, in many jurisdictions no formalities are necessary to start an association...
. One of them was the "Academy of Nations", which was founded in 1921 in the USA by Robert T. Browne and Arvid Reuterdahl. Other members were Thomas Jefferson Jackson See
Thomas Jefferson Jackson See
Thomas Jefferson Jackson See, was an American astronomer of high potential who ended a colorful life with no real accomplishment in astronomy or physics...
, as well as Gehrcke and Mohorovičić in Germany. However, the alliance disappeared already in the mid 1920s in Germany and 1930 in the USA.
Wazeck (2009), pp. 293-378
Chauvinism and antisemitism
Shortly before and during World War IWorld War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, there appeared some nationalistically motivated criticisms of relativity and modern physics. For example, Pierre Duhem
Pierre Duhem
Pierre Maurice Marie Duhem was a French physicist, mathematician and philosopher of science, best known for his writings on the indeterminacy of experimental criteria and on scientific development in the Middle Ages...
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.
Hentschel (1990), pp. 123-131
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 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 mood, Einstein openly speculated in a newspaper article that, in addition to insufficient knowledge of theoretical physics, antisemitism was also a reason 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, subsequently Weyland, Lenard, Stark and others clearly showed their antisemitic prejudices by beginning to combine their criticisms with racism
Racism
Racism is the belief that inherent different traits in human racial groups justify discrimination. In the modern English language, the term "racism" is used predominantly as a pejorative epithet. It is applied especially to the practice or advocacy of racial discrimination of a pernicious nature...
. For example, Theodor Fritsch
Theodor Fritsch
Theodor Fritsch, originally Emil Theodor Fritsche , was a German publisher and pundit. His anti-semitic writings did much to influence popular German opinion against Jews in the late 19th and early 20th centuries...
emphasized the alleged negative consequences of the "Jewish spirit" within relativity, and the far right-press continued this propaganda unhindered. After the murder of Walther Rathenau
Walther Rathenau
Walther Rathenau was a German Jewish industrialist, politician, writer, and statesman who served as Foreign Minister of Germany during the Weimar Republic...
(1922) and murder threats against Einstein, he left Berlin for some time. Gehrcke's book on "The mass suggestion of relativity theory" (1924) was not antisemitic itself, but it was praised by the far-right press as describing an alleged typical Jewish behavior. Philipp Lenard
Philipp Lenard
Philipp Eduard Anton von Lenard , known in Hungarian as Lénárd Fülöp Eduárd Antal, was a Hungarian - German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties...
in 1922 spoke about the "foreign spirit" as the foundation of relativity, and afterward he joined the Nazi party in 1924; Johannes Stark
Johannes Stark
Johannes Stark was a German physicist, and Physics Nobel Prize laureate who was closely involved with the Deutsche Physik movement under the Nazi regime.-Early years:...
did the same in 1930. Both were proponents of the so-called German Physics
Deutsche Physik
Deutsche Physik or Aryan Physics was a nationalist movement in the German physics community in the early 1930s against the work of Albert Einstein, labeled "Jewish Physics"...
, which only accepted scientific knowledge based on experiments, and only if accessible to the senses. According to Lenard (1936), this is the "Aryan 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
Bruno Thüring
Bruno Jakob Thüring was a German physicist and astronomer.Thüring studied mathematics, physics, and astronomy at the University of Munich and received his doctorate in 1928, under Alexander Wilkens and Arnold Sommerfeld...
and others. For example, Müller claimed that relativity is a pure "Jewish affair" and it would correspond to the "Jewish essence" etc., while Thüring made comparisons between the Talmud
Talmud
The Talmud is a central text of mainstream Judaism. It takes the form of a record of rabbinic discussions pertaining to Jewish law, ethics, philosophy, customs and history....
and relativity.
Kleinert (1979)
Beyerchen (1982)
Hentschel (1990), pp. 131-150
Posch (2006)
Wazeck (2009), pp. 271-392
Einstein (1920a)
Lenard (1936)
Stark/Müller (1941)
Thüring (1941)
Accusations of plagiarism and priority discussions
Some critics like Lenard, Gehrcke, Reuterdahl 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:Hentschel (1990), pp. 150-162
Wazeck (2009), pp. 194-216
Laue (1917)
Laue (1921b)
Gehrcke (1916)
Lenard (1921b)
- Johann Georg von SoldnerJohann Georg von SoldnerJohann Georg von Soldner was a German physicist, mathematician and astronomer, first in Berlin and later in 1808 in Munich.-Life:...
(1801) was credited for his calculation of the deflection of lightTests of general relativityAt its introduction in 1915, the general theory of relativity did not have a solid empirical foundation. It was known that it correctly accounted for the "anomalous" precession of the perihelion of Mercury and on philosophical grounds it was considered satisfying that it was able to unify Newton's...
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 GerberPaul GerberPaul Gerber was a German physicist. He studied in Berlin from 1872-1875. In 1877 he became a teacher at the Realgymnasium in Stargard in Pommern...
(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 VoigtWoldemar VoigtWoldemar Voigt was a German physicist, who taught at the Georg August University of Göttingen. Voigt eventually went on to head the Mathematical Physics Department at Göttingen and was succeeded in 1914 by Peter Debye, who took charge of the theoretical department of the Physical Institute...
(1887) derived a transformationHistory of lorentz transformationsThe Lorentz transformations relate the space-time coordinates, relative to a particular inertial frame of reference , and the coordinates of the same event relative to another coordinate system moving in the positive x-direction at a constant speed v, relative to the rest system...
, which is very similar to the Lorentz transformationLorentz transformationIn physics, the Lorentz transformation or Lorentz-Fitzgerald transformation describes how, according to the theory of special relativity, two observers' varying measurements of space and time can be converted into each other's frames of reference. It is named after the Dutch physicist Hendrik...
. 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 HasenöhrlFriedrich HasenöhrlFriedrich Hasenöhrl , was an Austro-Hungarian physicist.-Life:Friedrich Hasenöhrl was born in Vienna, Austria in 1874. His father was a lawyer and his mother belonged to a prominent aristocratic family...
(1904) applied the concept of electromagnetic massElectromagnetic massElectromagnetic mass was initially a concept of classical mechanics, denoting as to how much the electromagnetic field, or the self-energy, is contributing to the mass of charged particles. It was first derived by J. J. Thomson in 1881 and was for some time also considered as a dynamical...
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 PalágyiMenyhért PalágyiMenyhért Palágyi, in German Melchior or Meinhert Palagyi was a Hungarian philosopher, mathematician, and physicist of Jewish descent...
(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 to electromagnetic theory, the relativity principle, or to 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.Darrigol (2004) Another discussion concerns a possible mutual influence between Einstein and David Hilbert
David Hilbert
David Hilbert was a German mathematician. He is recognized as one of the most influential and universal mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of...
as regards completing the field equations
Einstein field equations
The Einstein field equations or Einstein's equations are a set of ten equations in Albert Einstein's general theory of relativity which describe the fundamental interaction of gravitation as a result of spacetime being curved by matter and energy...
of general relativity (see Relativity priority dispute
Relativity priority dispute
Albert Einstein presented the theories of Special Relativity and General Relativity in groundbreaking 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...
).
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 from 28 authors, and excerpts of publications from other 19 authors. The rest consists of a list that also includes people who 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 commented, those failures were due to the misunderstand of the relativity by the authors. For example, Hans ReichenbachHans Reichenbach
Hans Reichenbach was a leading philosopher of science, educator and proponent of logical empiricism...
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.
"If I were wrong, it would only have taken one." --Albert Einstein, commenting on the book 100 Authors Against Einstein
According to Goenner, the contributions to the book are a mixture of mathematical-physical incompetence, hubris
Hubris
Hubris , also hybris, means extreme haughtiness, pride or arrogance. Hubris often indicates a loss of contact with reality and an overestimation of one's own competence or capabilities, especially when the person exhibiting it is in a position of power....
, 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
Emanuel Lasker
Emanuel Lasker was a German chess player, mathematician, and philosopher who was World Chess Champion for 27 years...
and Hjalmar Mellin
Hjalmar Mellin
Robert Hjalmar Mellin was a Finnish mathematician and functional theorist.He studied at the University of Helsinki and later in Berlin under Karl Weierstrass. He is most noted as the developer of the integral transform known as the Mellin transform...
) were present - but an inadequate reaction of the academic educated citizenship, which didn't know 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 two persons were substantially younger. Two authors (Reuterdahl, von Mitis) were antisemitic 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, Emanuel Lasker
Emanuel Lasker
Emanuel Lasker was a German chess player, mathematician, and philosopher who was World Chess Champion for 27 years...
, Oskar Kraus
Oskar Kraus
Oskar Kraus was a Czech philosopher, jurist.-Life:Oskar Kraus, who converted from the Jewish to the Protestant faith, was the son of Hermann Kraus and Clara Reitler-Eidlitz...
, Menyhért Palágyi
Menyhért Palágyi
Menyhért Palágyi, in German Melchior or Meinhert Palagyi was a Hungarian philosopher, mathematician, and physicist of Jewish descent...
).
Goenner (1993b)
Wazeck (2009), pp. 356-361
Israel et al. (1931)
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 electrodynamicsQuantum electrodynamics
Quantum electrodynamics is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved...
. Therefore, fundamental criticism (like those of Herbert Dingle
Herbert Dingle
Herbert Dingle , an English physicist and natural philosopher, who served as president of the Royal Astronomical Society from 1951 to 1953, is best known for his opposition to Albert Einstein's special theory of relativity and the protracted controversy that this provoked.-Biography:Dingle was born...
, Louis Essen
Louis Essen
Louis Essen FRS O.B.E. was an English physicist whose most notable achievements were in the precise measurement of time and the determination of the speed of light...
, Petr Beckmann
Petr Beckmann
Petr Beckmann was a statistician and physicist who became a well-known advocate of libertarianism and nuclear power...
, Maurice Allais
Maurice Allais
Maurice Félix Charles Allais was a French economist, and was the 1988 winner of the Nobel Memorial Prize in Economics "for his pioneering contributions to the theory of markets and efficient utilization of resources."...
, Tom van Flandern
Tom Van Flandern
Thomas C Van Flandern was an American astronomer and author specializing in celestial mechanics. Van Flandern had a career as a professional scientist, but was noted as an outspoken proponent of non-mainstream views related to astronomy, physics, and extra-terrestrial life. He also published the...
) have not been taken serious by the scientific community, and due to the lack of quality of many critical publications (found in the process of Peer review
Peer review
Peer review is a process of self-regulation by a profession or a process of evaluation involving qualified individuals within the relevant field. Peer review methods are employed to maintain standards, improve performance and provide credibility...
) they were rarely accepted for publication in reputable scientific journals. So, as in the 1920s, most of the critical works have been published in small publications houses, alternative journals (like "Apeiron" or "Galilean Electrodynamics"), or private websites (like Conservapedia
Conservapedia
Conservapedia is an English-language wiki project written from a self-described American conservative Christian point of view. The website considers itself to be a supporter of "conservative, family-friendly" content...
).Newscientist and Cosmosmagazine Consequently, where criticism of relativity has been dealt with by the scientific community, it has mostly been in historical studies.
Hentschel (1990)
Wazeck (2009)
However, this does not mean that there is no further development in modern physics. The enormous progress of technologies leads to extremely precise ways to test the predictions of relativity, and so far it successfully passed all tests (such as in particle accelerators to test special relativity, and by astronomical observations to test general relativity). 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
String theory
String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...
and loop quantum gravity
Loop quantum gravity
Loop quantum gravity , also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the theories of quantum mechanics and general relativity...
. Some variations of those models also predict violations of Lorentz invariance on a very small scale.
Mattingly (2005)
Will (2006)
Liberati (2009)
See also
- This article is based on the German version.
- Alternatives to general relativityAlternatives to general relativityAlternatives to general relativity are physical theories that attempt to describe the phenomena of gravitation in competition to Einstein's theory of general relativity.There have been many different attempts at constructing an ideal theory of gravity...
- History of special relativityHistory of special relativityThe history of special relativity consists of many theoretical results and empirical findings obtained by Albert Michelson, Hendrik Lorentz, Henri Poincaré and others...
- Fringe scienceFringe scienceFringe science is scientific inquiry in an established field of study that departs significantly from mainstream or orthodox theories, and is classified in the "fringes" of a credible mainstream academic discipline....
- Anatoli Logunov
Historic analyses
.
|
Relativity papers
. . . . . .
|
Critical works
. . (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.) Siehe auch englische Übersetzung. |
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 MPIWGMax Planck Institute for the History of ScienceThe Max Planck Institute for the History of Science in Berlin was established in March 1994. Its research is primarily devoted to a theoretically oriented history of science, principally of the natural sciences, but with methodological perspectives drawn from the cognitive sciences and from...
. - 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.
- CosmosMagazine: Was Einstein a fake?