# Authors of Relativity

Who are the authors of relativity theory? From Wikipedia:

"[Nikola] Tesla also believed that much of Albert Einstein's relativity theory had already been proposed by Ruđer Bošković, stating in an unpublished interview:
...the relativity theory, by the way, is much older than its present proponents. It was advanced over 200 years ago by my illustrious countryman Ruđer Bošković, the great philosopher, who, not withstanding other and multifold obligations, wrote a thousand volumes of excellent literature on a vast variety of subjects. Bošković dealt with relativity, including the so-called time-space continuum ...'.[79]

Also from Wiki:
"Poincaré never acknowledged Einstein's work on special relativity.... A few years before his death Einstein commented on Poincaré as being one of the pioneers of relativity, saying "Lorentz had already recognised that the transformation named after him is essential for the analysis of Maxwell's equations, and Poincaré deepened this insight still further ...."[23]"

I've searched quite a bit but I've mostly found only laughable seemingly anti-Semitic Angenda slander of Einstein without any credible sources. I would like to know if there is any credit given to Einstein that he does not deserve. For instance, apparently he cited no references in his 1905 paper on SR, but clearly before that, others had contributed to relativity, for instance, I believe Poincare introduced length contraction, and apparently Nikola Tesla thought Ruđer Bošković was the inventor of relativity. Is there any validity to this? I am skeptical of these accusations. It seems far-fetched that Einstein stole SR but not GR, Brownian motion, and the photoelectric effect, or that he stole all of them. Please , if you can, give me any information about the foundations of relativity, or any credible sources I can read on the topic.

Thank you, Rich

bcrowell
Staff Emeritus
Gold Member
If you're quoting from a web page, please give a URL. The Tesla quote is not currently on WP in the form you quote, but something similar seems to be here, in the article on Tesla: http://en.wikipedia.org/wiki/Nikola_Tesla and here, in the article on Boskovic: http://en.wikipedia.org/wiki/Ruđer_Bošković Tesla's claim is complete nonsense.

Lorentz had the wrong interpretation of the mathematics, and that's why Einstein is normally credited with creating relativity. The history is well known: http://en.wikipedia.org/wiki/History_of_special_relativity

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JesseM
Lorentz had already come up with the Lorentz transformation and noted that the laws of electromagnetism were invariant under this transformation, but Einstein was the first to propose that all fundamental laws of physics could be Lorentz-invariant, and that this would mean all the different frames given by the transformation would really be on equal footing (so, for example, we can't say that either of two rulers in relative motion are objectively 'contracted', each one is contracted in the other one's rest frame--Lorentz and others before Einstein had assumed that there was some preferred aether frame and that rulers moving relative to it were contracted in some objective way, and thought there might be some way to determine which frame is the aether frame). See here and here for some more info on what had been postulated before Einstein's 1905 paper.

As for Boskovic, he lived in the 1700s and could not have anticipated all of special relativity (in particular he had no reason to think the speed of light would be the same relative to every observer), but reading up on him he was ahead of his time in many ways, and did anticipate the basic notion that all motion can only be defined in a relative way. P. 88 of this book says:
More specifically, Boscovich claimed that the observer can never observe the world as it is. He can only describe the interface (or "difference") between himself and the world. A first logical deduction from this principle was the finding that a state of external motion of the observer relative to the world is equivalent to a state of motion of the whole world relative to a stationary observer.

bcrowell
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Gold Member
[Boskovic] did anticipate the basic notion that all motion can only be defined in a relative way.

But that notion is false. For example, the Sagnac effect allows you to tell whether you are in a state of absolute rotational motion, without having to define your motion relative to anything else.

Coming up with some fuzzy philosophical idea isn't the same as creating a complete mathematical theory that makes specific predictions.

If one is going to define "relativity" as loosely as Tesla apparently did, then Galileo deserves priority.

JesseM
But that notion is false. For example, the Sagnac effect allows you to tell whether you are in a state of absolute rotational motion, without having to define your motion relative to anything else.
I don't think it's clearly false, it depends on what you mean by "motion". The sagnac effect tells you you're not moving inertially (and thus your proper acceleration is nonzero), but one can adopt a coordinate system where both your velocity and acceleration are zero while inertial objects move in circles, there's nothing invalid about this perspective and by making use of a metric one can write the laws of physics in a mathematical form that's the same in non-inertial and inertial frames. So, in this sense it is correct to say that all motion can only be defined in a relative sense.

In any case, I agree that Boscovic cannot actually be said to have discovered special relativity...

I saw a special on PBS on Einsteins wife that stated that he did a lot of his early work with her. Then after their break up his work went down hill. But, he got recognized by lorentz that had already got into the subject and that is how he got known for the theory was through him.

Telsa seems to become a big internet science hero recently, I don't think he would be able accomplish anything like Chuk Norris, lol.

bcrowell
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Gold Member
I don't think it's clearly false, it depends on what you mean by "motion". The sagnac effect tells you you're not moving inertially (and thus your proper acceleration is nonzero), but one can adopt a coordinate system where both your velocity and acceleration are zero while inertial objects move in circles, there's nothing invalid about this perspective and by making use of a metric one can write the laws of physics in a mathematical form that's the same in non-inertial and inertial frames. So, in this sense it is correct to say that all motion can only be defined in a relative sense.

I agree that this kind of discussion requires a careful definition of what you mean by motion -- and of course, the definitions that we now know are useful, based on relativity, can't possibly be the definitions that Boskovic used. Einstein himself, living three centuries later than Boskovic, initially had some wrong ideas about how motion should be interpreted in relativity. (He believed that GR was going to be more Machian than it really was. This was why, for example, he was upset by the existence of the Schwarzschild solution, describing a pointlike object alone in the universe. It's also why he worked very hard to prove that gravitational waves were physically meaningless coordinate waves.)

I don't really see where you're going with the issues you raise about the Sagnac effect. If an observer can detect his own rotation without reference to any external object, then clearly rotation is absolute, not relative. For example, you lock me in a physics laboratory with no windows. I observe the motion of a gyroscope and determine that the lab is rotating with a certain angular velocity vector $\boldsymbol{\omega}$. This isn't a statement about frames, it's a statement about observations of a gyroscope. It's true that the Einstein field equations are invariant under smooth coordinate transformations, but that doesn't mean that I can make the observations go away by switching to a different set of coordinates, it means that the observations *won't* go away. Suppose that I find that I can explain my observations using a model in which spacetime is flat, and I find it convenient to use Minkowski coordinates $\textbf{x}$. Then I can tell that the perfect symmetry that would exist in purely Machian physics is broken because I can find a particular axis which is the axis of rotation. The asymmetry is encoded mathematically in the coordinate velocities of various objects in the lab. Now suppose I transform to new coordinates $\textbf{x}'$, which are related to the $\textbf{x}$ coordinates by rotation with angular velocity $\boldsymbol{\omega}$. I can make objects in the lab have zero coordinate velocities, but I haven't gotten rid of the observations, the rotation, or the asymmetry. The asymmetry is now encoded in the transformed version of the metric.

In any case, I don't think it's even necessary to talk about frames of reference (which GR doesn't really have in the global sense) or inertial versus noninertial motion. In particular, rotation in GR isn't linked with non-inertial motion as it is in Newtonian mechanics. For example, the earth revolves around the sun, but the earth's proper acceleration is zero. Another good example is that there are spacetimes that describe rotating universes. Obviously if the entire universe is rotating, it can't be rotating relative to something else. Our universe may very well be rotating at some rate. The best model-independent upper limit that I know of is 0.1"/century [Clemence 1957]. The best model-dependent upper limit is orders of magnitude lower [Collins 1973], but it's not zero.

Clemence 1957 - Clemence, C.M. (1957). 'Astronomical Time', Rev. Mod. Phys. Vol. 29, p. 2
Collins 1973 - Collins, C.B., and Hawking, S.W. (1973). 'The Rotation and Distortion of the Universe', Mon. Not. R. astr.Soc. Vol 162, p. 307

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JesseM
I don't really see where you're going with the issues you raise about the Sagnac effect. If an observer can detect his own rotation without reference to any external object, then clearly rotation is absolute, not relative. For example, you lock me in a physics laboratory with no windows. I observe the motion of a gyroscope and determine that the lab is rotating with a certain angular velocity vector $\boldsymbol{\omega}$. This isn't a statement about frames, it's a statement about observations of a gyroscope.
If you define rotation in terms of those gyroscopic effects (or the Sagnac effect or any other local observations), then yes, your rotation is absolute. If you define rotation as a certain type of movement through space, then it depends on your coordinate system. In relativity you can at least use accelerometer readings to conclude you must be accelerating relative to all inertial frames, of course (it's interesting to note that in Newtonian mechanics you can't even do that, since the laws in accelerating frames work just like inertial frames with the addition of fictitious forces, and within a confined lab there's no way to be sure if forces you observe acting on gyroscopes or accelerometers are fictitious or "real"). You may be arguing that given what we know today it's better to use definitions that don't actually refer to change in position (and I don't disagree with that), but Boskovic didn't know all we know today, and his statements about motion being relative seem to be more naturally interpreted in terms of the idea that we are free to treat any given body as being motionless while other bodies move relative to it.

bcrowell
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his statements about motion being relative seem to be more naturally interpreted in terms of the idea that we are free to treat any given body as being motionless while other bodies move relative to it.

...which is false. Consider the famous example of the two planets from A. Einstein, "The foundation of the general theory of relativity," Annalen der Physik 49 (1916) 769, which is reproduced on p. 315 of this book: http://www.lightandmatter.com/genrel/

When Einstein wrote this, he believed that GR would be fully Machian. As it turned out, it wasn't that Machian. There are other theories that are more Machian, such as Brans-Dicke gravity. Since observations support GR and not Brans-Dicke gravity, we know that the universe is not actually as Machian as Einstein wanted it to be. In particular, we now know that what Einstein predicted in the two planets example (no equatorial bulge on either planet) is not what GR actually predicts and is not what would actually happen.

Have you read the classic paper on Brans-Dicke gravity, C. Brans and R. H. Dicke, Mach's Principle and a Relativistic Theory of Gravitation,'' Physical Review 124 (1961) 925? It's very readable, and if you have access to it I'd highly recommend it.

JesseM
...which is false. Consider the famous example of the two planets from A. Einstein, "The foundation of the general theory of relativity," Annalen der Physik 49 (1916) 769, which is reproduced on p. 315 of this book: http://www.lightandmatter.com/genrel/

When Einstein wrote this, he believed that GR would be fully Machian. As it turned out, it wasn't that Machian.
I don't think it's right to say the claim "is false" without more careful definitions, you seem to be conflating the issue of whether we are free to treat any body as being at rest vs. whether the laws of physics are "Machian", which I would consider to be separate issues. It's true that in Einstein's example of two planets in an otherwise empty universe, one planet bulges outward due to rotation while the other doesn't and this conflicts with Machian ideas, but this doesn't mean we aren't free to use a coordinate system where every point on the surface of the bulging planet is at rest while points on the surface of the non-bulging planet are moving in circles, it's just that the metric will look different in this coordinate system than it does in a different coordinate system where it's the surface of the non-bulging planet that's at rest.

bcrowell
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I don't think it's right to say the claim "is false" without more careful definitions, you seem to be conflating the issue of whether we are free to treat any body as being at rest vs. whether the laws of physics are "Machian", which I would consider to be separate issues. It's true that in Einstein's example of two planets in an otherwise empty universe, one planet bulges outward due to rotation while the other doesn't and this conflicts with Machian ideas, but this doesn't mean we aren't free to use a coordinate system where every point on the surface of the bulging planet is at rest while points on the surface of the non-bulging planet are moving in circles, it's just that the metric will look different in this coordinate system than it does in a different coordinate system where it's the surface of the non-bulging planet that's at rest.

Looks like we're stuck and not convincing one another. Oh, well :-)

atyy
Accelerated motion is *absolute* *relative* to an inertial frame. So motion is absolute and relative?

Regarding credit for SR, apart from Fitzgerald, Lorentz, Poincare and Einstein, there was still one more development by Minkowski before SR was brought to its modern understanding. Einstein's undisputed role was to make Newtonian dynamics (ie. the rest of classical physics apart from Maxwell's equations) consistent with the principle of relativity and the Lorentz transforms.

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bcrowell
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Gold Member
Accelerated motion is *absolute* *relative* to an inertial frame. So motion is absolute and relative?
How would you classify the rotation of the universe described in #7? There's no frame that covers the whole universe, so we can't make the inertial/noninertial frame distinction.

JesseM
Looks like we're stuck and not convincing one another. Oh, well :-)
But what are you unconvinced about? I hope you would not disagree that my statement "we are free to treat any given body as being motionless while other bodies move relative to it" is correct, given my clarification the phrase "we are free to treat any given body as motionless" should be interpreted to mean "we can come up with a coordinate system where a given body (like the rotating planet) is motionless and, given the correct expression for the metric in this coordinate system, the usual laws of GR will give accurate predictions about all physical questions, therefore this coordinate system is just as good as any other for doing physics". Perhaps you initially interpreted "we are free to treat any given body as motionless" in a different way (for example, perhaps you interpreted the statement to be claiming that even if we don't use a metric, the dynamical equations for the laws of physics expressed in terms of each coordinate system would look identical, which clearly is not the case if one coordinate system is inertial while the other is non-inertial), but since I was the one who made the statement I think it's my right to define the meaning of the words...in any case I can't see how this is anything other than a question of semantics, if you think there is some substantive disagreement here please clarify.

JesseM
How would you classify the rotation of the universe described in #7? There's no frame that covers the whole universe, so we can't make the inertial/noninertial frame distinction.
In this case I think it's called a "rotating universe" because of what a locally inertial observer would see visually when looking at distant bits of the matter that fills the universe. From this page:
Imagine you are in a laboratory without windows floating around somewhere in the universe. If you and the other objects in the laboratory get pressed against the walls, you would say that the laboratory is rotating, and centrifugal forces are responsible for the effects. Now, the laboratory happens to be equipped with small engines that can be used to control the rotation. Use the engines until you have totally eliminated the centrifugal forces, and thereby the rotation. When done, drill some peepholes in the laboratory (but please make sure you don't lose your air supply). Observe the galaxies. If you find that the galaxies rotate around you, then the universe is said to be rotating.

atyy
...which is false. Consider the famous example of the two planets from A. Einstein, "The foundation of the general theory of relativity," Annalen der Physik 49 (1916) 769, which is reproduced on p. 315 of this book: http://www.lightandmatter.com/genrel/

When Einstein wrote this, he believed that GR would be fully Machian. As it turned out, it wasn't that Machian. There are other theories that are more Machian, such as Brans-Dicke gravity. Since observations support GR and not Brans-Dicke gravity, we know that the universe is not actually as Machian as Einstein wanted it to be. In particular, we now know that what Einstein predicted in the two planets example (no equatorial bulge on either planet) is not what GR actually predicts and is not what would actually happen.

Have you read the classic paper on Brans-Dicke gravity, C. Brans and R. H. Dicke, Mach's Principle and a Relativistic Theory of Gravitation,'' Physical Review 124 (1961) 925? It's very readable, and if you have access to it I'd highly recommend it.

I haven't read the paper. But I'm going to guess first. How about relative to a preferred family of observers, or relative to the gravitational field (spacetime metric)? Ok, I will read it now.

bcrowell
Staff Emeritus
Gold Member
But what are you unconvinced about?
I could ask you the same thing :-)

I hope you would not disagree that my statement "we are free to treat any given body as being motionless while other bodies move relative to it" is correct, given my clarification the phrase "we are free to treat any given body as motionless" should be interpreted to mean "we can come up with a coordinate system where a given body (like the rotating planet) is motionless and, given the correct expression for the metric in this coordinate system, the usual laws of GR will give accurate predictions about all physical questions, therefore this coordinate system is just as good as any other for doing physics".
I agree with the statement (2) "we can come up with [...] for doing physics." I don't agree that that's equivalent to (1) "we are free to treat [...] relative to it." Statement 2 is a statement about coordinate systems; it's true but not very interesting. Statement 1 makes it sound as though that restricted fact about coordinate systems had some broader physical significance. Statement 1 implies that there would be no equatorial bulge in Einstein's example of the two planets. Statement 1 implies that there can't be any such thing as a rotating cosmological solution (since there would be no way to discuss whether the universe was moving relative to something else). Statement 1 talks about "bodies," but GR isn't a theory of bodies, it's a theory of spacetime.

in any case I can't see how this is anything other than a question of semantics, if you think there is some substantive disagreement here please clarify.
I don't think it's just a matter of semantics. You can't take one lengthy statement and simply assert that you define it as being equivalent to some other lengthy statement. If we allow that, then I can assert that Aristotle's Physics is correct because I define it as being equivalent to the complete text of Hawking and Ellis. This whole question of how Machian the universe is is an empirically testable question, and people like Clifford Will put decades worth of effort into testing it in the 70's and 80's. They did real experiments and observations, and they found out that the universe wasn't very Machian.

Have you read the 1961 Brans-Dicke paper? Will's book Was Einstein Right? is also very good on this kind of thing.

[EDIT] Made a few edits to the above after posting it. I hope that doesn't cause confusion.

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atyy
@bcrowell - the rotation refers to the rotation of nearby worldlines. So it's like geodesic deviation - it's absolute relative to a given pair of wordlines (family of observers).

JesseM
I could ask you the same thing :-)
It's you who's claiming some of my statements are false, not the other way around.
bcrowell said:
I agree with the statement (2) "we can come up with [...] for doing physics." I don't agree that that's equivalent to (1) "we are free to treat [...] relative to it."
But clearly any disagreement about whether two ambiguous nontechnical statements in the English language are "equivalent" is a disagreement about semantics, not physics. I think it is "natural" to interpret the sentence "we are free to..." to just mean "we won't make any errors in our predictions if we use a coordinate system where the rotating object is at rest"; that may not be your preferred interpretation of the most "natural" way to interpret the sentence, but I don't think you can claim that it's a totally bizarre interpretation that no native English speaker well-versed in physics would agree with.
bcrowell said:
Statement 1 makes it sound as though that restricted fact about coordinate systems had some broader physical significance.
"Makes it sound as" is you reading between the lines, the sentence says no such thing explicitly and I clearly intended no such implication when I wrote it. There is a subjective element in interpreting the meaning of English sentences, do you think your interpretation is the only reasonable one and anyone who interprets it differently doesn't understand how the English language works?
bcrowell said:
Statement 1 implies that there would be no equatorial bulge in Einstein's example of the two planets.
You may think the most "natural" interpretation implies this, but that's not the same as saying the sentence itself clearly implies this and anyone who doesn't see such an implication is WRONG, period.
bcrowell said:
Statement 1 implies that there can't be any such thing as a rotating cosmological solution (since there would be no way to discuss whether the universe was moving relative to something else).
I already explained to you that the idea of a rotating universe can be understood in terms of how distant matter would behave as seen in a locally inertial frame. The statement that we can use any coordinate system we want needn't contradict the idea that local inertial frames have a special role in general relativity.
bcrowell said:
I don't think it's just a matter of semantics. You can't take one lengthy statement and simply assert that you define it as being equivalent to some other lengthy statement.
I can't do so in a completely arbitrary way, but if I honestly think that one lengthy statement can reasonably be intrepreted to have a particular meaning, and you find such an interpretation unnatural, that is a matter of semantics.
bcrowell said:
If we allow that, then I can assert that Aristotle's Physics is correct because I define it as being equivalent to the complete text of Hawking and Ellis.
I think you're being pretty unreasonable, there's a lot of middle ground between "every English statement has a totally clear and ambiguous meaning and thus there is a single correct answer to whether two statements are equivalent, anyone who disagrees is objectively incorrect" (which seems to be your position about my interpretation of the sentence that I wrote) and "every English statement is totally arbitrary and we can interpret Aristotle's Physics to mean the same think as Hawking & Ellis". The meaning of English sentences almost always includes some slight ambiguity, but we consider some interpretations as more "reasonable" and some as more "unreasonable" based on shared understanding among English speakers. If we found 100 native-English speakers who were also well-versed in relativity and presented them with my sentence "we are free to treat any given body as being motionless while other bodies move relative to it" followed by the interpretation "here, 'we are free to' just means that if we use a coordinate system where a given body is motionless and use the correct metric in that coordinate system, we will still get correct predictions about physical questions", I don't think all 100 would be unanimous that this was a totally unreasonable way of interpreting the original sentence. Do you disagree and think my interpretation is so bizarre that there would be unanimous agreement in such a group that my interpretation has no connection to the original sentence? If not, do you think that even when a group of intelligent and knowledgeable people disagree on the interpretation of a nontechnical sentence, there can be some basis for judging one interpretation to be the objectively correct one while the other interpretation is objectively wrong?
bcrowell said:
This whole question of how Machian the universe is is an empirically testable question
Yes, but it's one that the sentence as written says nothing about explicitly, you're just reading into it and unreasonably acting like your interpretation is the only possible valid way of reading that sentence.

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atyy
http://arxiv.org/abs/gr-qc/0011094
A No-Go Theorem About Rotation in Relativity Theory
Authors: David B. Malament
(Submitted on 27 Nov 2000)
Abstract: Within the framework of general relativity, in some cases at least, it is a delicate and interesting question just what it means to say that an extended body is or is not "rotating". It is so for two reasons. First, one can easily think of different criteria of rotation. Though they agree if the background spacetime structure is sufficiently simple, they do not do so in general. Second, none of the criteria fully answers to our classical intuitions. Each one exhibits some feature or other that violates those intuitions in a significant and interesting way. The principal goal of the paper is to make the second claim precise in the form of a modest no-go theorem.

bcrowell
Staff Emeritus
Gold Member
That's an interesting paper, atyy -- thanks for posting it! It seems to pose a serious obstacle to attempts to define rotation in GR in terms of the relative motion of objects, since it shows that such a definition is non-transitive. That is, it is not true that if A is nonrotating relative to B, and B is nonrotating relative to C, then A is nonrotating relative to C (assuming you want other reasonable conditions to be satisfied by the definition).

That is pretty self evident why Tesla is such a big internet celebrity.

People are curious/fear about what is unknown...since Tesla's experiments seem to be "flashy" and add his reclusive image of "mad scientist"...
and the fact that he made a bunch of random statements about having created a "death ray" etc.

Gullible people (and/or conspiracy theorists) obviously believe that he was a "forgotten genius" ...and according to multiple questions/answers on Yahoo Answers...many people think he is clearly superior to Einstein...especially since he was apparently critical of relativity.

Majority of people who raised the hype haven't studied any physics properly so obviously when they see "Tesla made Death Ray but he was forgotten (or government is preventing its construction, or other conspiracy)" and then "Einstein did relativity" (which they know nothing about) they think it is clear that the guy with death ray (according to the Internetz) is the mega genius here....and hype him up more.

Tesla claiming that Boscovich dealt with relativity somewhere in his 'thousand volumes' without specifying which one seems pretty worthless to me. Boscovich is best known for 'A theory of natural philosophy', which is an early attempt at a 'Theory of everything'. He does come up with ideas about parallel universes and a version of the cosmological constant, but I didn't find anything in it which suggested anything like relativity.

Who are the authors of relativity theory? From Wikipedia:
[..]
Also from Wiki:
"Poincaré never acknowledged Einstein's work on special relativity.... A few years before his death Einstein commented on Poincaré as being one of the pioneers of relativity, saying "Lorentz had already recognised that the transformation named after him is essential for the analysis of Maxwell's equations, and Poincaré deepened this insight still further ...."[23]"

I've searched quite a bit but I've mostly found only laughable seemingly anti-Semitic Angenda slander of Einstein without any credible sources. I would like to know if there is any credit given to Einstein that he does not deserve. For instance, apparently he cited no references in his 1905 paper on SR, but clearly before that, others had contributed to relativity, for instance, I believe Poincare introduced length contraction, and apparently Nikola Tesla thought Ruđer Bošković was the inventor of relativity. Is there any validity to this? I am skeptical of these accusations. It seems far-fetched that Einstein stole SR but not GR, Brownian motion, and the photoelectric effect, or that he stole all of them. Please , if you can, give me any information about the foundations of relativity, or any credible sources I can read on the topic.

Thank you, Rich

The relativity principle exists for centuries; Newtonian mechanics is relativistic, just not in the modern way!

If you read the original papers of the time of Lorentz (and they are increasingly available online), you will understand that he adapted his "electron" theory in order to make it relativistic at the request of Poincare, who was the first to propose that all fundamental laws of physics are Lorentz-invariant.
However, Einstein's 1905 papers on relativity contain quite some new elements. And although Einstein's 1905 paper lacks references, in 1907 he published a paper[1] in which he admitted the priority of Lorentz's 1904 paper.
Einstein can hardly be blamed for the reading inability of his readers!

1. http://wikilivres.info/wiki/Über_das_Relativitätsprinzip_und_die_aus_demselben_gezogenen_Folgerungen

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JesseM