אודיסאת איינשטיין ליחסות הכללית Einstein’s Odyssey to General Relativity

מאמר שלי על דרכו של איינשטיין לתורת היחסות הכללית: אודיסאת איינשטיין ליחסות הכללית

סיינטיפיק אמריקן ישראל

“Einstein’s Odyssey to General Relativity”, Scientific American Israel

את המונח “אודיסאה” ליחסות הכללית טבע פרופ’ ג’ון סטצ’ל מאוניברסיטת בוסטון והוא מייצג את המסע המפרך של איינשטיין בדרכו ליחסות הכללית. ראו המאמר של סטצ’ל למטה

Odyssey to general relativity is John Stachel’s memorable phraseology. See:

Stachel, John (1979). “Einstein’s Odyssey: His Journey from Special to General Relativity”. In Einstein from B to Z, 2002.

I am sorry but this piece is in Hebrew. You can read my book General Relativity Conflict and Rivalries, my papers on Einstein and general relativity and a short summary below.

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מפייסבוק: מארחים את ד”ר גלי וינשטיין לדבר על איינשטיין

SF1

My drawing of Einstein:      האיור שלי של איינשטיין

איינשטיין צעיר

And the original (I tried as hard as I could to draw a young Einstein…):       המקור

תמונה1

The article discusses the following topics:

1907. The Happiest thought of my life.

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1907-1911. The equivalence principle and elevator experiments.

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1911. Deflection of light and explaining deflection of light using an elevator thought experiment.

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1911-1912 (1916). The disk thought experiment, gravitational time dilation and gravitational redshift.

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1912. The disk thought experiment and non-Euclidean geometry.

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1912. Einstein to Marcel Grossmann: “Grossmann, you must help me or else I’ll go crazy!”. Grossmann searched the literature, and brought the works of Bernhard Riemann, Gregorio Curbastro-Ricci, Tullio Levi-Civita and Elwin Bruno Christoffel to Einstein’s attention. With Grossmann’s help Einstein searched for gravitational field equations for the metric tensor in the Zurich Notebook.

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1913-1914. The Entwurf theory. In 1913, Einstein and Michele Besso both tried to solve the new Entwurf field equations to find the perihelion advance of Mercury.

2October 1915. Einstein realizes there are problems with his 1914 Entwurf theory. November 1915. Einstein’s competition with David Hilbert.

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November 1915. Four ground-breaking papers: Einstein presents the field equations of general relativity, finds the advance of the perihelion of Mercury and predicts that a ray of light passing near the Sun would undergo a deflection of amount 1.7 arc seconds.

General Relativity without the Equivalence principle?

I have skimmed through this book Handbook of Spacetime:

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The following represents my impressions formulated after reading the sections about the equivalence principle.

I read this paper:

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However, Einstein did not write this wonderful passage in the letter to Robert Lawson. Here is the letter to Lawson (Einstein to Lawson, 22 January 1920):

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Einstein writes to Lawson in the above letter: “The article for Nature is almost finished, but it has unfortunately become so long that I very much doubt whether it could appear in Nature“. Indeed, in a 1920 unpublished draft of a paper for Nature, “Fundamental Ideas and Methods of the Theory of Relativity, Presented in Their Development”, Einstein wrote the above long paragraph describing him in 1907 sitting in the Patent Office. He was brooding on special relativity, and suddenly there came to him the happiest thought of his life:

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Let us analyze this passage. The man in free fall (elevator experiments): Special relativity is incorporated into general relativity as a model of space-time experienced by an observer in free fall, over short times and distances (locally):

Between 1905 and 1907, Einstein tried to extend the special theory of relativity so that it would explain gravitational phenomena. He reasoned that the most natural and simplest path to be taken was to correct the Newtonian gravitational field equation. Einstein also tried to adapt the Newtonian law of motion of the mass point in a gravitational field to the special theory of relativity. However, he found a contradiction with Galileo’s law of free fall, which states that all bodies are accelerated in the gravitational field in the same way (as long as air resistance is neglected). Einstein was sitting on a chair in my patent office in Bern and then suddenly a thought struck him: If a man falls freely, he would not feel his weight. This was the happiest thought of his life. He imagined an observer freely falling from the roof of a house; for the observer there is during the fall – at least in his immediate vicinity – no gravitational field. If the observer lets go of any bodies, they remain relative to him, in a state of rest or uniform motion, regardless of their particular chemical and physical nature. The observer is therefore justified in interpreting his state as being (locally) at rest. Einstein’s 1907 breakthrough was to consider Galileo’s law of free fall as a powerful argument in favor of expanding the special principle of relativity to systems moving non-uniformly relative to each other. Einstein realized that he might be able to generalize and extend special relativity when guided by Galileo’s law of free fall. The Galilean law of free fall (or inertial mass is equal to gravitational mass) became known as the weak principle of equivalence.

Lewis Ryder explains: “Some writers distinguish two versions of the equivalence principle: the weak equivalence principle, which refers only to free fall in a gravitational field and is stated… as The worldline of a freely falling test body is independent of its composition or structure; and the strong equivalence principle, according to which no experiment in any area of physics should be able, locally, to distinguish a gravitational field from an accelerating frame”.

There are several formulations of the weak and the strong principles of equivalence in the literature. By far the most frequently used formulation of the strong principle of equivalence is Einstein’s 1912 local principle of equivalence: In a local free falling system special relativity is valid. (See my book General Relativity Conflict and Rivalries. Einstein’s Polemics with Physicists, 2015, for further details).

Nick Woodhouse explains:

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in the chapter:

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Hence Joshi says:

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in the chapter:

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Lewis Ryder

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writes in the above paper:

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(i.e. Einstein 1911 paper: “On the Influence of Gravitation on the Propagation of Light”). He formulates the equivalence principle in the following way: “In a freely falling (non-rotating) laboratory occupying a small region of spacetime, the local reference frames are inertial and the laws of physics are consistent with special relativity”. He then writes:

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The equivalence principle enables us to find just one component g00 – of the metric tensor gmn. All components can be found (at least in principle) from the Einstein field equations. Ryder thus concludes that the equivalence principle is dispensable. I don’t quite agree with Ryder.

In my 2012 paper, “From the Berlin ‘Entwurf’ Field equations to the Einstein Tensor III: March 1916”, ArXiv: 1201.5358v1 [physics.hist-ph], 25 January, 2012 and also in my 2014 paper,  “Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story”, ArXiv: 1411.7370v [physics.hist-ph], 26 Nov, 2014, I demonstrate the following:  On November 18, 1915, Einstein found approximate solutions to his November 11, 1915 field equations and explained the motion of the perihelion of Mercury. Einstein’s field equations cannot be solved in the general case, but can be solved in particular situations. Indeed, the first to offer an exact solution was Karl Schwarzschild. Schwarzschild found one line element, which satisfied the conditions imposed by Einstein on the gravitational field of the sun, as well as Einstein’s field equations from the November 11, 1915 paper. Schwarzschild sent Einstein a manuscript, in which he derived his exact solution of Einstein’s field equations. In January, 1916, Einstein delivered Schwarzschild’s paper before the Prussian Academy, and a month later the paper was published. In March 1916 Einstein submitted to the Annalen der Physik a review article, “The Foundation of the General Theory of Relativity”, on the general theory of relativity. The paper was published two months later, in May 1916. The 1916 review article was written after Schwarzschild had found the complete exact solution to Einstein’s November 18, 1915 field equations. Even so, Einstein preferred not to base himself on Schwarzschild’s exact solution, and he returned to his first order approximate solution from November 18, 1915. In the final part of the 1916 review paper Einstein demonstrated that a gravitational field changes spatial dimensions and the clock period:

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This equation is further explained in my 2012 paper (page. 56):

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Neither did Einstein use the Schwarzschild solution nor was he guided by the  equivalence principle. He was rather using an approximate solution and the metric, the line element to arrive at the same factor he had obtained by assuming the heuristic equivalence principle. He thus demonstrated that the equivalence principle was a fundamental principle of his theory, because in 1912 he formulated an equivalence principle valid only locally  (see my book: General Relativity Conflict and Rivalries. Einstein’s Polemics with Physicists, 2015, p. 184). I further explain it below.

Ryder then explains: The equivalence principle is local (a complete cancelation of a gravitational field by an accelerating frame holds locally). However, over longer distances two objects in free fall at different places in a realistic gravitational field move toward each other and this does not happen in an accelerating elevator. The cancelation of the gravitational field by an accelerating field is thus not complete. According to general relativity this effect (tidal effect) is a consequence of the curvature of space-time:

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Although the equivalence principle might have been a heuristic guide to Einstein in his route to the fully developed theory of general relativity, Ryder holds that it is now irrelevant.

I don’t agree with Ryder’s conclusion which resembles that of John Lighton Synge (and Hermann Bondi). Indeed the equivalence principle is not valid globally (i.e. for tidal effects). Although the strong equivalence principle can at best be valid locally, it is still crucial for the general theory of relativity:

  1. Einstein formulated an equivalence principle which is valid only locally. Special relativity is valid locally and space-time is locally the Minkowski space-time.
  2. The principle of equivalence is fundamental for a metric theory and for our understanding of curved space-time: Freely falling test bodies move along geodesic lines under the influence of gravity alone, they are subject to an inertio-gravitational field . The metric determines the single inertio-gravitational field (affine connection), and there is breakup into inertia and gravitation relative to the acceleration. According to the equivalence principle, the components of the affine connection vanish in local frames. John Stachel quotes a passage from Einstein’s letter to Max von Laue:

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Stachel, John, “How Einstein Discovered General Relativity: A Historical Tale with Some Contemporary Morals”, Einstein B to Z, 2002.

Indeed Ryder quotes J. L. Synge :

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Einstein’s equivalence principle was criticized by Synge:

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Synge, J. L. (1960). Relativity: The General Theory (Amsterdam, The Netherlands: North Holland Publishing Co).

And Hermann Bondi reacted to Einstein’s principle of equivalence:

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Bondi also said (‘NO SUCCESS LIKE FAILURE …’: EINSTEIN’S QUEST FOR GENERAL RELATIVITY, 1907–1920, Michel Janssen):

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Other authors contributing to the Handbook of Spacetime write the following:

Graham S. Hall in his paper:

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writes the following:

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“The choice of a geodesic path (Einstein’s principle of equivalence) reflects the results of the experiments of Eötvös and others, which suggest that the path of a particle in a pure gravitational field is determined by its initial position and initial velocity”. This is not Einstein’s equivalence principle. This is the Galilean principle of equivalence or the weak equivalence principle.

And according to Vesselin Petkov:

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the geodesic line is indeed a manifestation of Galileo’s free fall law:

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Ryder presents tests for the equivalence principle. The operation of the global positioning system, the GPS, is a remarkable verification of the time dilation. The GPS system consists of an array of 24 satellites, which describe an orbit round the earth of radius 27,ooo km, and are 7000 km apart, and every 12 hours travel at about 4km/s.  Each satellite carries an atomic clock, and the purpose is to locate any point on the earth’s surface. This is done by sensing radio signals between the satellites and the receiver on the earth, with the times of transmission and reception recorded. The distances are then calculated. Only three satellites are needed to pinpoint the position of the receiver on the earth. Relativistic effects must be taken into account arising both from special relativity (time dilation: moving clocks on the satellites run slower than clocks at rest on the surface of the earth) and from general relativity (gravitational time dilation/gravitational frequency shift: when viewed from the surface of the Earth, clocks on the satellites appear to run faster than identical clocks on the surface of the earth). The combined effect (the special relativistic correction and the general relativistic correction) is that the clocks on the satellites run faster than identical clocks on the surface of the earth by 38.4 microseconds per day. The clocks thus need to be adjusted by about 4 x 10-10s per day. If this factor is not taken into account, the GPS system ceases to function after several hours. This provides a stunning verification of relativity, both special and general.

Neil Ashby dedicates his paper to the GPS:

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and gives a critical reason why the equivalence principle is indeed relevant. Consider again the GPS (global positioning system) or generally, Global navigation satellite systems (GNNS). For the GPS or GNNS, the only gravitational potential of significance is that of the earth itself. The earth and the satellites fall freely in the gravitational field of the sun (and external bodies in the solar system). Hence, according to the equivalence principle one can define a reference system which is locally very nearly inertial (with origin at the earth’s center of mass). In this locally inertial coordinate system (ECI) clocks can be synchronized using constancy of the speed of light (remember that special relativity is incorporated into general relativity as a model of space-time experienced locally by an observer in free fall):

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One writes an approximate solution to Einstein’s field equation and obtains that clocks at rest on earth

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run slow compared to clocks at rest at infinity by about seven parts in 1010.

Unless relativistic effects on clocks [clock synchronization; time dilation, the apparent slowing of moving clocks (STR); frequency shifts due to gravitation, gravitational redshift(GTR)] are taken into account, GPS will not work. GPS is thus a huge and remarkable laboratory for applications of the concepts of special and general relativity. In addition, Shapiro signal propagation delay (an additional general relativistic effect) and spatial curvature effects are significant and must be considered at the level of accuracy of 100 ps of delay. Ashby mentions another effect on earth that is exactly cancelled:

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Wesson in this paper:

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presents the standard explanation one would find in most recent textbooks on general relativity:

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The Christoffel symbols are also used to define the Riemann tensor, which encodes all the relevant information about the gravitational field. However, the Riemann tensor has 20 independent components, and to obtain field equations to solve for the 10 elements of the metric tensor requires an object with the same number of components. This is provided by the contracted Ricci tensor. This is again contracted (taking its product with the metric tensor) to obtain the Ricci curvature scalar.  This gives a kind of measure of the average intensity of the gravitational field at a point in space-time. The combination of the Ricci tensor and the Ricci scalar is the Einstein tensor and it comprises the left hand-side of Einstein’s field equations.

At every space-time point there exist locally inertial reference frames, corresponding to locally flat coordinates carried by freely falling observers, in which the physics of general relativity is locally indistinguishable from that of special relativity. In physics textbooks this is indeed called the strong equivalence principle and it makes general relativity an extension of special relativity to a curved space-time.

Wesson then writes that general relativity is a theory of accelerations rather than forces and refers to the weak equivalence principle:

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As said above, Einstein noted that if an observer in free fall lets go of any bodies, they remain relative to him, in a state of rest or uniform motion, regardless of their particular chemical and physical nature. This is the weak principle of equivalence: The worldline of a freely falling test body is independent of its composition or structure. The test body moves along a geodesic line. The geodesic equation is independent of the mass of the particle. No experiment whatsoever is able, locally, to distinguish a gravitational field from an accelerating system – the strong principle of equivalence (see Ryder above). A freely falling body is moving along a geodesic line. However, globally space-time is curved and this causes the body’s path to deviate from a geodesic line and to move along a non-geodesic line. Hence we speak of geodesics, manifolds, curvature of space-time, rather than forces.

José G. Pereira explains the difference between curvature and torsion (and force) (see paper here):

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General relativity is based on the equivalence principle and geometry (curvature) replaces the concept of force. Trajectories are determined not by force equations but by geodesics:

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How do we know that the equivalence principle is so fundamental?  Gravitational and inertial effects are mixed and cannot be separated in classical general relativity and the energy-momentum density of the gravitational field is a pseudo-tensor (and not a tensor):

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General relativity is grounded on the equivalence principle. It includes the energy-momentum of both inertia and gravitation:

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In 1928 Einstein proposed a geometrized unified field theory of gravitation and electromagnetism and invented teleparallelism. Einstein’s teleparallelism was a generalization of Elie Cartan’s 1922 idea. Picture20

According to Pereira et al: “In the general relativistic description of gravitation, geometry replaces the concept of force. This is possible because of the universal character of free fall, and would break down in its absence. On the other hand, the teleparallel version of general relativity is a gauge theory for the translation group and, as such, describes the gravitational interaction by a force similar to the Lorentz force of electromagnetism, a non-universal interaction. Relying on this analogy it is shown that, although the geometric description of general relativity necessarily requires the existence of the equivalence principle, the teleparallel gauge approach remains a consistent theory for gravitation in its absence”.

See his paper with R. Aldrovandi and K. H. Vu: “Gravitation Without the Equivalence Principle”, General Relativity and Gravitation 36, 2004, 101-110.

Petkov explains in his paper: (see further above)

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the following:

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The bottom line is that classical general relativity is fundamentally based on the equivalence principle. One cannot reject Einstein’s route to the theory of general relativity.

 

 

 

 

 

 

 

The Road to Relativity and Dishonesty in Scientific Research

Prof. Hanoch Gutfreund, the former president of the Hebrew University of Jerusalem, has been plagiarizing my papers and book. To call prof. Gutfreund prolific in plagiarizing my work would be an understatement. The serious damages I sustain from this in Israel are enormous, actually it is far more damaging than I previously thought. I wrote to the president of the Hebrew University in Jerusalem but the latter has not even answered my email. Hence it seems he fails to take responsibility for damage caused by plagiarism. I am not surprised.

In the book, The Road to Relativity: The History and Meaning of Einstein’s “The Foundation of General Relativity” (an annotated facsimile of Einstein’s original handwritten manuscript on general relativity and explanation of Einstein’s manuscript and equations), co-authored by prof. Jürgen Renn, prof. Gutfreund writes:

cosmo

Prof. Gutfreund has picked this passage with only slight changes from my 2013 paper: “George Gamow and Albert Einstein: Did Einstein say the cosmological constant was the “biggest blunder” he ever made in his life?”, ArXiv: 1310.1033v [physics.histph], 03 Oct, 2013.

My name is not mentioned in note 4:

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Compare the above paragraph from prof. Gutfreund’s book, The Road to Relativity: The History and Meaning of Einstein’s “The Foundation of General Relativity, to the abstract of my paper, “George Gamow and Albert Einstein: Did Einstein say the cosmological constant was the ‘biggest blunder’ he ever made in his life”:

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And compare the penultimate paragraph from prof. Gutfreund’s book, The Road to Relativity: The History and Meaning of Einstein’s “The Foundation of General Relativity to two paragraphs from my paper, “George Gamow and Albert Einstein: Did Einstein say the cosmological constant was the ‘biggest blunder’ he ever made in his life?”:

blunder1

blunder2

In 2016 I received this message from ResearchGate:

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My paper gained traffic but no citations, but prof. Gutfreund, who plagiarized my paper, received the citations.

Allen I. Janis writes in his review: “The Road to Relativity: The History and Meaning of Einstein’s ‘The Foundation of General Relativity’.” American Journal of Physics 84, 2016: “An interesting sideline in this chapter has to do with the frequently heard story that Einstein called his introduction of the cosmological constant the biggest mistake of his life. It seems there is no evidence that Einstein ever said or wrote this, and that it is in fact an invention of George Gamow”.

Gamow

It is quite obvious the Prof. Gutfreund has effectively paraphrased the passage from my paper. On November 30, 2015,  Prof. Gutfreund said in his plenary lecture, “100 years of General Relativity – What are we Celebrating?” At the Berlin Conference: A Century of General Relativity:

“But you know there is this Myth that Einstein when he abandoned the cosmological constant he said this is the worst error that I made. There is no evidence for that. Probably he never said that”.

My second bookGeneral Relativity Conflict and Rivalries. Einstein’s Polemics with Physicists (published on December 1, 2015) has a whole chapter dedicated to Einstein’s “biggest blunder”. This chapter is based on my 2013 ArXiv paper: “George Gamow and Albert Einstein: Did Einstein say the cosmological constant was the ‘biggest blunder’ he ever made in his life?”:

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Hence, plagiarism of my 2013 paper on Albert Einstein and George Gamow causes damage to my second book and to my academic status.

In addition, Prof. Gutfreund writes in The Road to Relativity: The History and Meaning of Einstein’s “The Foundation of General Relativity”:

gut

A circle around the origin of coordinates is a rotating disk (in his 1916 paper “The Foundation of General Relativity”, Einstein calls the disk “a circle around the origin”).

In the preceding passage prof. Gutfreund have paraphrased a passage from my 2012 paper, “From the Berlin ‘Entwurf’ Field equations to the Einstein Tensor III: March 1916”, ArXiv: 1201.5358v1 [physics.hist-ph], 25 January, 2012:

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and from my 2014 paper, “Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story”, ArXiv, 1411.7370v [physics.hist-ph], 26 Nov, 2014 [Equation (70) is my equation (6) and equation (71) is my equation (11)]:

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Towards the end of his 1916 paper, “The Foundation of General Relativity”, Einstein demonstrates that the gravitational field changes spatial dimensions and the clock period. However, nowhere does Einstein directly relate the rotating disk story to the  above derivation. I have invoked this interpretation of Einstein’s paper. Einstein writes:

Ein5 Ein4

Digital Einstein

On November 30, 2015, Prof. Gutfreund lifted another passage from my paper, “Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story” and changed a word here and there, in his plenary lecture, “100 years of General Relativity – What are we Celebrating? at the Berlin Conference: A Century of General Relativity:

“Another thing which he could have done. So he already knew the Schwarzschild solution, because the Schwarzschild correspondence is in December. He wrote this paper [review paper, 1916] later. He submitted it only in March. So he could have used this Schwarzschild solution who showed a simpler derivation of the motion of the perihelion and of the bending of light and he did not do it”.

In the abstract of my paper, “Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story”, ArXiv, 1411.7370v [physics.hist-ph], 26 Nov, 2014, I wrote:

“On November 18, 1915 Einstein reported to the Prussian Academy that the perihelion motion of Mercury is explained by his new General Theory of Relativity: Einstein found approximate solutions to his November 11, 1915 field equations. Einstein’s field equations cannot be solved in the general case, but can be solved in particular situations. The first to offer such an exact solution was Karl Schwarzschild. Schwarzschild found one line element, which satisfied the conditions imposed by Einstein on the gravitational field of the sun, as well as Einstein’s field equations from the November 18, 1915 paper. On December 22, 1915 Schwarzschild told Einstein that he reworked the calculation in his November 18 1915 paper of the Mercury perihelion. Subsequently Schwarzschild sent Einstein a manuscript, in which he derived his exact solution of Einstein’s field equations. On January 13, 1916, Einstein delivered Schwarzschild’s paper before the Prussian Academy, and a month later the paper was published. In March 1916 Einstein submitted to the Annalen der Physik a review article on the general theory of relativity. The paper was published two months later, in May 1916. The 1916 review article was written after Schwarzschild had found the complete exact solution to Einstein’s November 18, 1915 field equations. Einstein preferred in his 1916 paper to write his November 18, 1915 approximate solution upon Schwarzschild exact solution (and coordinate singularity therein).”

He could have though picked the idea from my 2012 paper, Weinstein, Galina, “From the Berlin ‘Entwurf’ Field equations to the Einstein Tensor III: March 1916”, ArXiv: 1201.5358v1 [physics.hist-ph], 25 January, 2012:

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Einstein’s equations in his 1916 paper, “The Foundation of General Relativity”:

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In my book, General Relativity Conflict and Rivalries. Einstein’s Polemics with Physicists  I have also developed my previous ideas from my paper, “Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story”.

 

 

 

 

 

האוניברסיטה העברית מעניקה פרס לפרופסור חנוך גוטפרוינד שעשה לי פלגיאט

האוניברסיטה העברית החליטה להעניק לפרופסור חנוך גוטפרוינד את פרס שמואל רוטברג. אני שואלת: האם פרופסור חנוך גוטפרוינד מקבל את הפרס על זה שהוא עשה לי פלגיאט למאמרים ולספר שלי על אלברט איינשטיין ותורת היחסות הפרטית והכללית בהרצאה שהוא נתן בכנס בברלין ב-2015? האם הוא מקבל את הפרס על זה שהוא סילק אותי מכנסי איינשטיין והתעלל בי? אספר לכם את הסיפור כהלכתו: האוניברסיטה העברית וארכיון איינשטיין בראשות פרופסור חנוך גוטפרוינד ארגנו בינואר 2015 כנס בינלאומי לרגל מאה שנה לתורת היחסות הכללית של אלברט איינשטיין. זהו בדיוק תחום ההתמחות שלי, אלברט איינשטיין ותורת היחסות הפרטית והכללית. כתבתי בנושא זה שני ספרים שנרכשו על ידי אוניברסיטאות מובילות בעולם, כתבתי מאמרים רבים על אלברט איינשטיין ותורת היחסות הפרטית והכללית, מאמרים שהתפרסמו בכל העולם. מן הראוי שכבוגרת האוניברסיטה העברית אוזמן להרצות בכנס. אבל “למרבה הפלא” מארגני הכנס, פרופסור חנוך גוטפרוינד (מהאוניברסיטה העברית), פרופסור ימימה בן מנחם (מהאוניברסיטה העברית) ופרופסור דיאנה בוכוולד (מפרויקט איינשטיין), שיבצו במקומי מרצים, שתחום התמחותם כלל אינו איינשטיין ותורת היחסות הפרטית והכללית, מרצים שלא מבינים כלום באיינשטיין ובתורת היחסות וגמגמו וקשקשו שטויות וטעויות בהרצאה שלהם וכל זה בפני קהל מדענים שכלל כמה מומחים בעלי שם מהעולם בתחום תורת היחסות הכללית, הוי לאותה בושה! הנה ההודעה על הכנס

einst2

כמה חודשים אחר כך בחודש דצמבר 2015 יצא המרצע מן השק: נערך בברלין במכון מקס פלאנק כנס בינלאומי לרגל 100 שנה לתורת היחסות הכללית של איינשטיין. כמובן פניתי וביקשתי להרצות בכנס אבל לא הוזמנתי להרצות. הנה ההודעה על הכנס

conference Berlin

וכך כשאני יושבת בבית צפיתי בהרצאות הכנס שהועלו לאינטרנט. והנה בהרצאת הפתיחה בארוחת הערב החגיגית קיבל פרופ’ חנוך גוטפרוינד את כבוד מתן ההרצאה הראשונה. פרופ’ חנוך גוטפרוינד הרצה על: “מאה שנים לתורת היחסות הכללית – מה אנו חוגגים?”. וראו איזה פלא, פרופ’ חנוך גוטפרוינד, נשיא האוניברסיטה העברית לשעבר, מרצה רעיונות מתוך המאמרים והספר שלי, מבלי להזכיר את שמי. בדיון בשולחן עגול פרופ’ חנוך גוטפרוינד אפילו ציטט מבלי להרגיש טעות אחת שנפלה במאמר שלי ובספר שלי. אם כך יש סיבה לכל דבר: סולקתי מכנסי איינשטיין כדי שלא אפריע לפלגיאט והוא, שכנראה לא היה מודע לנפלאות האינטרנט, חשף את הגניבה. בסוף ההרצאה זכה פרופ’ חנוך גוטפרוינד למחיאות כפיים סוערות. אודה על האמת מאוד נהניתי ממחיאות הכפיים הסוערות. ועל כך רבותי מוענק פרס שמואל רוטברג לפרופ’ חנוך גוטפרוינד

נכתב The Road to Relativity בספר של פרופ’ חנוך גוטפרוינד

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הערה מספר 4 מציינת את המקורות הביבליוגרפיים. כמובן שהשם שלי והמאמר שלי לא נמצאים שם למרות שמה שכתוב למעלה לקוח ממאמר שכתבתי ב-2013 כפי שתראו מיד. אז למה לא להוסיף גם את השם שלי ואת המאמר שלי להערה מספר 4? כי זה לא מכובד להוסיף את השם שלי אז פשוט גונבים ממני

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תשוו את זה לקטעים מהמאמר שלי שנכתב שנתיים קודם לכן

George Gamow and Albert Einstein: Did Einstein say the cosmological constant was the “biggest blunder” he ever made in his life?”, ArXiv: 1310.1033v [physics.histph], 03 Oct, 2013.

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אני קבלתי את ההודעה הבאה

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חמישים אנשים קראו את המאמר שלי אבל לא ציטטו אותו. לעומת זאת ציטטו את הספר של פרופ’ חנוך גוטפרוינד בדיוק בקטע שמדבר על ג’ורג’ גמוב ואלברט איינשטיין במאמר הבא

Allen I. Janis writes in his review: “The Road to Relativity: The History and Meaning of Einstein’s ‘The Foundation of General Relativity’.” American Journal of Physics 84, 2016:

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The Genesis and ‘Renaissance’ of General Relativity: Jürgen Renn’s talk

All the Berlin Century of General Relativity and MPIWG conference talks and discussions are on the web site of the Max Planck Institute for the History of Science in Berlin.

I shall begin by presenting the opening remarks of prof. Jürgen Renn’s talk, “The ‘Renaissance’ of General Relativity: Social and Epistemic Factors”, and thereafter I shall list my various comments on this talk. I shall present my views at the end regarding the term “Renaissance” describing the period from 1955 to the end of 1964.

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Prof. Jürgen Renn:

“This talk is about explaining historical change; how we preliminary see the various stages of the history of general relativity: there was the genesis of general relativity [the period from 1907 to 1916] where Einstein worked not quite but almost alone with a few helpers. There were the formative years [the period from 1916 to 1925], in which the theory was discussed among a group of experts; there was then what Jean Eisenstaedt has epically termed the low-water mark period [the period from 1925 to 1955]; and then comes the renaissance [the period from 1955 to 1964]. Clifford Will gave the name to this period; and for us historians then came the golden ages [the period from 1964 to the mid 1970s] and today and the future, but I will not talk about that.

So the main challenge is to explain how development went from the low-water mark period to the renaissance; how what we today see as the basic theory of cosmology and astrophysics came back into the mainstream of physics after the low-water mark period. There were many factors of course and we have concentrated on several scenarios, examining them in preliminary ways to try to come up with what we think as a convincing explanation.

Let me start to outline the thesis. We think that the renaissance was mainly due to two factors:

One was the discovery of the untapped potential of general relativity as it has been created as a tool for theoretical physics. Hidden secrets that were discovered in this period, hidden potential of application, these would not have been explored and actively developed had it not been within a community that was just forming in this period.

[The second factor] We think that the renaissance is also very much history of a community, in which for the first time a real community of relativists and cosmologists emerged. We have kind of loosely been talking of relativists and cosmologists, even when referring to the twenties and the thirties [1920s and 1930s]. This is a somewhat anachronistic use of terms, because the real community only emerged as we see it during the period of the renaissance.

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So you see already that the general approach is one that combines epistemological aspects with sociological aspects, and that is very much the spirit of our thinking. Robert Schulmann [a speaker in the conference] used the terminology of internalist and externalist. So we see this very much as a development that can only be understood if you combine the cognitive, the epistemological side, with the sociological developments parallel to it”.

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My comments on this talk:

Prof. Jürgen Renn says: “There was the genesis of general relativity where Einstein worked not quite but almost alone with a few helpers. There were the formative years, in which the theory was discussed among a group of experts; there was then what Jean Eisenstaedt has epically termed the low-water mark period”.

I think that even during the genesis of general relativity, between 1912 and 1916, Einstein’s interaction with and response to eminent and non-eminent scientists and his ongoing discussions with other scientists contributed to the formation of general relativity. The efforts invested by physicists like Max Abraham, Gunnar Nordström, Gustav Mie, David Hilbert and others, which presented differing outlooks and discussions revolving around the theory of gravitation, were relegated to the background. Those works that did not embrace Einstein’s overall conceptual concerns – these primarily included the heuristic equivalence principle and Mach’s ideas (later called Mach’s principle) – were rejected, and authors focused on Einstein’s prodigious scientific achievements. However, one cannot discard Einstein’s response to the works of Abraham, Nordström, Mie, Tullio Levi-Civita, Hilbert and others. On the contrary, between 1912 and 1915 (the so-called genesis of general relativity) Einstein’s response to these works, and corrections made by these scientists to his work, constitutes a dynamic interaction that assisted him in his development (so-called genesis) of the general theory of relativity. In my book, General Relativity Conflict and Rivalries I show that general relativity was not developed as a single, coherent construction by an isolated individual, brooding alone. Instead, general relativity was developed through Einstein’s conflicts and interactions with other scientists, and was consolidated by his creative process during these exchanges.

Indeed, performing a historical research and also applying comparative research in a sociological context, we can emphasize the limits and associated problems tracing Einstein’s “odyssey”, i.e. intellectual road to the general theory of relativity. An intellectual approach emphasizes the simplistic hero worship narrative. In addition, some philosophers embrace externalist theories of justification and others embrace internalist theories of justification. There are many different versions of internalism and externalism, and philosophers offered different conceptions of internalism and externalism.

I would like to comment on the “formative years” and the “low-water mark” period. I show in my book General Relativity Conflict and Rivalries that between 1916 and 1955, Einstein was usually trusted as the authority on scientific matters. His authority in physics is revealed even on first-rate mathematicians and physicists. For example, in 1918 Felix Klein demonstrated to Einstein that the singularity in the de Sitter solution to the general relativity field equations was an artefact of the way in which the time coordinate was introduced. Einstein failed to appreciate that Klein’s analysis of the de Sitter solution showed that the singularity could be transformed away. In his response to Klein, Einstein simply reiterated the argument of his critical note on the de Sitter solution. In 1917-1918 the physicist-mathematician Hermann Weyl’s position corresponded exactly to Einstein’s when he criticized de Sitter’s solution; Weyl’s criticism revealed the influence of Einstein’s authority in physics even on first-rate mathematicians like Weyl.

Two other examples from the introduction of my book:

In March 1918, before publishing the book Space-Time-Matter, Weyl instructed his publisher to send Einstein the proofs of his book. In the same month, Weyl also instructed his publisher to send David Hilbert the proofs of his book. Hilbert looked carefully at the proofs of Weyl’s book but noticed that the latter did not even mention his first Göttingen paper from November 20, 1915, “Foundations of Physics”. Though Weyl mentioned profusely Einstein’s works on general relativity, no mention was made of Hilbert’s paper. Einstein received the proofs page-by-page from the publisher and read them with much delight and was very impressed. However, Einstein, an initial admirer of the beauty of Weyl’s theory, now raised serious objections against Weyl’s field theory. Einstein’s objection to Weyl’s field theory was Weyl’s attempt to unify gravitation and electromagnetism by giving up the invariance of the line element of general relativity. Weyl persistently held to his view for several years and only later finally dropped it.

Einstein also seemed to influence Sir Arthur Stanley Eddington when he objected to what later became known as “black holes”. In his controversy during the Royal Astronomical Society meeting of 1935 with Subrahmanyan Chandrasekhar, Eddington argued that various accidents may intervene to save a star from contracting into a diameter of a few kilometres. This possibility, according to Eddington, was a reductio ad absurdum of the relativistic degeneracy formula. Chandrasekhar later said that gravitational collapse leading to black holes is discernible even to the most casual observer. He, therefore, found it hard to understand why Eddington, who was one of the earliest and staunchest supporters of the general theory of relativity, should have found the conclusion that black holes may form during the natural course of the evolution of stars, so unacceptable. However, it is very reasonable that Eddington, who was one of the earliest and staunchest supporters of Einstein’s classical general relativity, found the conclusion that “black holes” were so unacceptable, because he was probably influenced by Einstein’s objection to the Schwarzschild singularity.

Prof. Jürgen Renn explained in his talk: “We think that the renaissance is also very much a history of a community, in which for the first time a real community of relativists and cosmologists emerged. We have kind of loosely been talked of relativists and cosmologists, even when referring to the twenties and the thirties. This is a somewhat anachronistic use of terms, because the real community only emerged as we see it during the period of the renaissance”.

I would like to comment on the proposal to call the period from 1955 to 1964 the “renaissance” of general relativity. Clearly, in the atmosphere of cinquecento Florence or Milan, a scientist and artist needed a community. Actually for the first time in history, in renaissance Italy there were concentrations of scientists, writers, artists and patrons in close communities and courts. There were communication and interaction between those communities. Historians have reconstructed what went in these communities and how these communities functioned. Hence renaissance is a suitable historical term to describe the period from 1955 to 1964.

Updated July 2016, another talk by Jürgen Renn: the sixth biennial Francis Bacon Conference, “General Relativity at 100”, Bacon Award Public Lecture: (I did not attend this conference but the talk was uploaded to YouTube):

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In 1907 in the patent office, Einstein was sitting down to write a review article in which he reviewed all the phenomena of physics in order to adapt them to the new framework of space and time established by special relativity. It was a routine task and dealing with gravitation in that context was also a routine task, so it seemed at the beginning.

[My comment: Einstein said in 1933, in the Glasgow lecture: “I came a step closer to the solution of the problem for the first time, when I attempted to treat the law of gravity within the framework of the special theory of relativity.” Apparently, sometime between September 1905 and September 1907 Einstein had already started to deal with the law of gravity within the framework of the special theory of relativity. When did he exactly start his work on the problem? Einstein did not mention any specific date, but in the Glasgow lecture he did describe the stages of his work presumably prior to 1907].

But then Einstein had to deal with the principle that was already established by Galileo hundreds of years ago, namely, the universality of free fall, the fact that all bodies fall with the same acceleration. How can these two be reconciled? When two people, one on the moving train and one on the platform each drop a stone, will the two stones hit the ground simultaneously? According to classical, Newtonian physics yes, but according to special relativity no. That is surprising. Was there any way to impose the universality of free fall and maintain Galileo’s principle?

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The following is what inspired Einstein. Later he recalled in 1920: “Then came to me the happiest thought of my life in the following form. In an example worth considering the gravitational field only has a relative existence in a manner similar to the electric field generated by electromagnetic induction. Because for an observer in free-fall from the roof of a house, there is during the fall – at least in his immediate vicinity – no gravitational field”. Now the great thing is that this allowed Einstein to simulate gravity by acceleration and he could now treat accelerated frames of reference with the help of relativity, so he had a handler in the framework of special relativity, but in a new way that preserved universality of free fall. He could now predict that light bends in a gravitational field. The principle of equivalence (elevator experiments – linear acceleration, a heuristic guide).

Where did the idea of a generalization of the special relativity principle to accelerated motion actually come from? Einstein was particularly fascinated by Ernst Mach’s historical critical analysis of mechanics. What could Einstein learn from Mach? Mach had reconsidered Newton’s bucket experiment. Why does the water rise when it stars rotating? Newton’s answer was the following: because it moves with respect to absolute space. Mach’s answer was different: he claimed that it moves because it moves with respect to the fixed stars. That would make it a relative motion, an inertia, an interaction of bodies in relative motion with respect to each other: the water and the stars.

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Rotation – heuristic guide

Besides Mach’s critique of mechanics, there is another element which can be identified in what Einstein called the happiest thought of his life. Einstein said (1920): “Then came to me the happiest thought of my life in the following form. In an example worth considering the gravitational field only has a relative existence in a manner similar to the electric field generated by electromagnetic induction. Because for an observer in free-fall from the roof of a house, there is during the fall – at least in his immediate vicinity – no gravitational field” (not italicized in the original). Use electromagnetic field theory as a mental model. We can see that it was the analogy of the gravitational field theory with the well-known theory of the electromagnetic field, on which Einstein of course was a specialist, that inspired him to the happiest thought as well, alongside the influence of Mach.

Now with the help of Mach, Einstein was in the position to complete the analogy between electromagnetic theory on the one hand and gravitational theory on the other hand by conceiving gravitation and inertia together as corresponding to the electromagnetic field. This analogy will guide him all these years from 1907 till 1915 to the completion of general relativity.

Let us look at the milestones of the genesis of general relativity. Usually this is portrayed as a drama in three acts:

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[My comment: John Stachel wrote in his paper “The First Two Acts”, Einstein from B to Z, p. 261, that in 1920 Einstein himself wrote a short list of “my most important scientific ideas” in a letter to Robert Lawson (April 22, 1920):

1907 Basic idea for the general theory of relativity

1912 Recognition of the non-Euclidean nature and its physical determination by gravitation

1915 Field equations of gravitation. Explanation of the perihelion motion of Mercury.

Einstein’s words provide the warrant for comparing the development of general relativity to a three-act drama]:

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According to Jürgen Renn: The problem here is that this portrait, this drama here leaves out the villain in this story, what is usually considered a villain, namely a theory on which Einstein worked between 1913 and 1915, in Zurich mostly but later also in Berlin, where he discarded it. It is called the preliminary or the draft and in German, the Entwurf theory. Now the point is what for other accounts is the villain of the story, a theory that was discarded, in my account, my book [? not yet published?] is the actual hero.

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[My comment: I see what Jürgen Renn means, but I don’t think that for other historical accounts the Entwurf theory is a so-called villain of the story, a theory that is discarded in accounts of historians. Jürgen Renn even mentions these historians in his talk – Michel Janssen and John Stachel. What he jokingly calls the “villain”, the Entwurf theory, is a major part of my book, General Relativity Conflict and Rivalries, December 2015 and it is spread over many pages of it].

But let us proceed in order. At the begging of 1911 Einstein became the chair of physics at the German university of Prague, his first full professorship. Parague: What did Einstein achieve in 1912? He knew that the field had to be a combination of gravitation and inertia, but he did not know how to represent it mathematically. Fortunately the problem had two parts: equation of motion – the field tells matter how to move, and field equation – matter tells the field how to behave. He thus first tried to solve the problem of the equation of motion. And in particular the simple case how does a body move when no other forces, other than gravitation and inertia, act on it. Again the analogy with electromagnetism came to his rescue. It made sense that other special cases of dynamic gravitational fields such as the forces acting in a rotating frame of reference… [?] It should be possible to consider such a system at rest and the centrifugal forces acting there as dynamical gravitational forces. That’s what Einstein took from Mach. But the clue is a combination of gravity and inertia. So what could he learn?

Let us look at a rotating disk and try to measure its circumference with little roods. The disk is set into motion. Because of the length contraction predicted by special relativity, the rods would be shrunk, so that we need more of them to cover the circumference. In other words, the ratio between the circumference and the diameter would be larger than pi. This simple thought experiment gave Einstein the idea that, to describe general dynamical gravitational fields one needs to go beyond Euclidean geometry.

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Non-Euclidean geometries were known. Einstein himself was not too familiar with non-Euclidean geometries. He had some courses at the ETH, he had skipped some courses at the ETH, but he did know that a straight line in such a geometry corresponds to a straightest line, or a geodesic. That solved for him the problem of the equation of motion, because when no other forces act in such a geometry, a particle would just follow the straightest possible line. Now the program of the new theory was clear. (John A, Wheeler: “matter tells space-time how to curve; curved space-time tells matter how to move”).

In the summer of 1912, Einstein returned to Zurich. He knew that he could describe a curved space-time by the metric tensor. He knew that he could define the deviation of space-time from Euclidean flat geometry in terms of the metric tensor.  A metric tensor is a complicated object:

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The metric tensor replaces the one Newtonian gravitational potential with ten gravitational potentials. He could even write down the equation of motion in terms of the metric tensor, he achieved that relatively quickly. But he had no clue as how to find a field equation for this complicated object, the metric tensor, these ten gravitational potentials.

One of the most important sources for our story is a notebook in which Einstein entered his calculations, in the winter of 1912-1913, the so-called Zurich Notebook.

The following fraternity of scholars provided historical-critical-mathematical-physical interpretation of the Zurich Notebook (it took them 10 years to interpret Einstein’s calculations):

Einstein scholars

Einstein’s first attempts to deal with the mathematics of the metric tensor look rather pedestrian. He tried to bring together the metric tensor with what he knew about the gravitational field equation, which was also relatively little.

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When Einstein was desperate he called his old friend Marcel Grossmann: “Grossman you have got to help me or I will go crazy!” Grossman had helped Einstein to survive his exams and he got him his job at the patent office. Now he helped him master the problem of gravitation. Indeed, one immediately recognizes Grossman’s intervention in the notebook. His name appears next to the Riemann tensor, the crucial object for building a relativistic field equation. Einstein immediately used it to form what he considered a candidate to the left hand-side of the field equation.

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Einstein and Grossmann found that these field equations do not match their physical expectations. It turned out to be difficult to reconcile Einstein’s physical expectations with the new formalism. Groping in the dark, Einstein and Grossmann essentially hit upon the correct field equations, in the winter of 1912-1913, three years before the final paper, in the weak field limit:

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But Einstein and Grossmann found that these field equations do not match their physical expectations. Eventually they had to learn how to adapt these physical expectations to the implications of the new formalism: we are talking about a learning experience that took place between a mathematical formalism and new physical concepts that were being shaped during the process.

Jürgen Renn then gives the following metaphor [a machine] to explain the mechanism behind a field equation (the Einstein-Grossmann Entwurf gravitational field equation): Einstein started out with a hand made mathematical formalism, at least before Grossmann came into the game, but it did the job. Extracting from the source of the field (mass and energy) a gravitational field. That’s what a field equation is all about. Of course it was most crucial that the familiar special case of Newtonian gravity would also come out in the appropriate circumstances. And Einstein had to make sure that this machine was firmly grounded in basic physical principles and in particular in the conservation of energy and momentum. But he also wanted to generalize the principle of relativity to accelerated motions and he looked for a machine that worked in more general coordinate systems, but at that point he didn’t know quite at which. The later point was unclear to Einstein.

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The problem was that it was not clear whether that machine would actually deliver the requested physical results. With Grossmann came the dream for a much more sophisticated machine, a machine that worked for all coordinate systems because it was generally covariant:

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Here the starting point was a sophisticated mathematical formalism based on the Riemann tensor, and then of course the machine had to work in the same way: the source makes a field, but does the Newtonian limit come out right? And is the machine firmly grounded in the principles of energy and momentum conservation? It certainly doesn’t look that quite way. In any way it was generally covariant, working in all coordinate systems. The problem was that it was not entirely clear whether that machine would actually deliver the requested physical results and what kind of tweaking it would take to get them. In short, the mechanism was great but the output was uncertain. Given this situation, Einstein could now peruse two different strategies:

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*physical requirements: the Newtonian limit and the energy momentum conservation.

In the winter of 1912-1913, Einstein and with him Grossmann constantly oscillated between these two strategies. At the end of the winter he decided for one of them: the physical strategy. Well not quite, but rather a physical strategy tweaked and adapted to match the requirements of energy-momentum conservation and a generalized principle of relativity. So it was a home made extension of the original machine.

[My comment: The “physical strategy” and the “mathematical strategy” and the “oscillation” between them are memorable phraseology of Jürgen Renn. These had already been invented by Jürgen Renn several years ago. You can find it in many papers by Jürgen Renn. For instance Renn, Jürgen and Sauer, Tilman, “Pathways out of Classical Physics”, The Genesis of General Relativity 1, 2007, 113-312].

The result of the collaboration between Einstein and Grossmann in the winter of 1912-1913 was a hybrid theory, the so-called Entwurf or draft theory, the villain or hero mentioned before. Why was the theory, “Draft of a Generalized Theory of Relativity and a Theory of Gravitation” a hybrid theory? It was a hybrid theory because the equation of motion (the field tells matter how to move) is generally covariant (retaining its form in all coordinate systems), but the field equation (matter tells the field how to behave) is not generally covariant. It was not even clear in which coordinate system the field equation would be covariant. Nevertheless, Einstein was quite proud. To his future wife Elsa he wrote: “I finally solved the problem a few weeks ago. It is a bold extension of the theory of relativity together with the theory of gravitation. Now I must give myself some rest, otherwise I will go kaput”. But was it worth the effort? Wasn’t the Entwurf theory just a blind alley and a waste of time (for more than two and a half years)? Most accounts say yes and speak of a comedy of errors.

[My comment: As I mentioned previously, I am afraid I don’t really agree with this conclusion. Other historians don’t say yes. In my account, for instance, in my book General Relativity Conflict and Rivalries, I demonstrate that the Entwurf theory plays a crucial role in Einstein’s development of the November 1915 theory. I refrain, however, from using the terms “bridges”, “scaffolding” and other metaphors Einstein did not use (see below) because I think that, these terms and metaphors embed constraints that impact the understanding of the historical narrative. I rather prefer Einstein’s own terms, for instance, “heuristic guide”. Hence, Einstein was guided by the 1913 calculation of the perihelion of Mercury. So was he guided by the 1914 variational principle, formalism].

But if the Entwurf theory was important, what was its role? What function did it have for the creation of the general theory of relativity, if it turned out to be a wrong theory at the end? To answer that question we shall use another metaphor: the Entwurf theory as a scaffolding for building an arch or a bridge between physics and mathematics (Michel Janssen’s metaphor). The building of a bridge between physics and mathematics. On its basis, Einstein first calculated the Mercury perihelion motion, and working out its mathematical structure, and by “its”, meaning the preliminary Entwurf draft theory. Einstein worked out its mathematical structure and set up a variational formalism for it.

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The Mercury calculation eventually helped him to solve the problem of the Newtonian limit and the variational formalism helped him to solve the other problem he had encountered with the mathematical strategy, that is, the conservation of energy and momentum. All this prepared the situation of November 1915, when it eventually came to a situation when the scaffolding was torn down.

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Let us look at the first issue, the issue of the Mercury perihelion motion (a problem studied in detail by Michel Janssen). In 1913 Einstein together with Michele Besso calculated the Mercury perihelion motion on the basis of the Entwurf theory and the value which they miscalculated came out too small.  The theory predicated only 18″per century. This did not shatter, however, Einstein’s confidence in that theory. Einstein never mentioned this unsatisfactory result until 1915 but he reused this method developed under the auspices of the Entwurf theory in November 1915. The method of calculation,  the scaffolding, could be used in the final November theory. The creation of general relativity was a team effort. Besso had a role in the perihelion calculation in building a scaffolding for the transition to the final theory. The Mercury calculation helped Einstein understand the problem of Newtonian limit and accept the field equation he had earlier discarded. The Mercury (perihelion) calculation of 1913 really did act as a scaffolding for what Einstein achieved in November 1915, when he redid this calculation now on the basis of the correct theory.

Einstein’s colleagues were amazed how quickly he could calculate. David Hilbert wrote in a postcard just a day after Einstein had submitted the paper: “Congratulations on conquering the perihelion motion. If I could calculate as fast as you can, the electron would be forced to surrender to my equations and the hydrogen atom would have to bring a note from home to be excused for not radiating”. However, all Einstein had to do is to redo the calculations for the perihelion motion in the Entwurf theory that he had done with Besso in 1913 but never published. Einstein did not bother to tell Hilbert about this earlier work. Apparently he wanted to give Hilbert a dose of his own medicine, seeing Hilbert as somebody who gave the impression of being superhuman by obfuscating his methods (Einstein to Ehrenfest, May 24, 1916).

In November 1915 the building of a scaffolding (Besso’s assistance) helped Einstein to overcome his earlier problems with extracting the Newtonian limit from the field equation found along the mathematical strategy.

But what about the second problem? The conservation laws of energy and momentum? Again the Entwurf theory served as a scaffolding. In 1914 Einstein and Grossmann set up a variational formalism for the Entwurf theory from which it was easy to derive the conservation laws. That formalism was general enough to allow the derivation of the conservation laws also for other theories, including the ones Einstein had discarded in the winter of 1912-1913.  You can use the variational formalism to make a candidate field equation for the physical strategy or you can change the settings, and then you get a different machine, a candidate field equation for the mathematical strategy.

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Having constructed such a formalism, the variational formalism, is what allowed Einstein to switch from the Entwurf theory to the theory he presented on November 4, 1915.

Einstein had resolved his two major problems that had prevented him in Zurich to accept candidate field equations along the mathematical strategy; namely the requirement to get out the Newtonian limit in the special case and the conservation laws. That confronts us with a puzzle: Why did Einstein not come back to the mathematical strategy right away once he had resolved these problems at the end of 1914?  He firmly believed in the Entwurf theory and had concocted all kinds of arguments in its favor, for instance the hole argument.

[My comment: I am afraid I don’t agree with this conclusion: I don’t think that at the end of 1914 Einstein had already resolved his two major problems (Newtonian limit and conservation laws). He was only able to resolve them in November 1915].

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But by October 1915, his perspective was gradually changing because problems with the Entwurf theory were gradually accumulated:

1) It did not explain the perihelion problem well, we have seen that. Einstein could live with it. He just put it under the rug and did not mention it in his publications.

2) It did not allow him to conceive rotation at rest. It was a major blow, considering his Machian vision.

3) And, it did not follow uniquely, as he had hoped, from the variational formalism that he had set up. But this failure was actually a blessing in disguise. It meant that the formalism was actually more general and not just tailor-made for the Entwurf theory. So he could use it.

So these problems were the prelude to the drama of November 1915 when Einstein published week after week his four conclusive publications on general relativity. On the 4th of November that is the transition from the Entwurf theory to the new mathematical objects; with an addendum on the 11th of November; the Mercury paper on the 18th of November, and the final field equations on the 25th. The first paper contains an interesting hint at what Einstein considered the “fatal prejudice” that had hindered him so far and also what was the key to the solution. The subsequent papers successively straighten out a logical structure of the theory, show that now the Mercury problem works and the final paper completes the logical structure of the theory.

In order to understand what the fatal prejudice was and what the key to the solution was, we have to once more time look at the mechanism at work here:

Picture40

There is indeed not just the source and the field. There is also the gravitational potential represented by the metric tensor and its connection with the gravitational field. That connection is expressed by a differential operator. One way to express this differential operator turned out to be a fatal prejudice, the other a key to the solution. As it turned out, it was essentially sufficient to change one element in the variational formalism developed for the Entwurf field equations, in order to get the theory from November the 4th, 1915. Namely, redefine the gravitational field.

Here are two ways in which Einstein expressed the connection between the field and the potential: One in the 1913 Entwurf theory and the other in the theory of November 4th. In the paper itself he speaks of the first way as a fatal prejudice and in a letter to Sommerfield he characterizes the second option as the key to the solution:

Picture41

In the end the transition from the Entwurf theory, based on the physical strategy, to the November 1915 theory, based on the sophisticated math of the Riemann tensor, seems to have been a rather simple step. But what made this step possible was the scaffolding represented by the variational formalism Einstein had built for the Entwurf theory.

[My comment: In my book, General Relativity Conflict and Rivalries, I demonstrate an additional element. Einstein wrote to Sommerfeld the following:

Picture4

“scalar derived from the energy tensor of matter, for which I write T in the following”.

Picture1Picture2

In my book I show how one can derive the second term on the right-hand side of the above November 25, 1915 equation on the basis of the variational formalism and on the basis of Einstein’s 1914 Entwurf theory and November 4th, 1915 paper. I connect between this latter derivation and the derivation of the November 4, 1915 field equation from the 1914 variation principle].

A variational formalism is a machine for making machines: It made it simpler to pass from a machine based on the fatal prejudice:

Picture42

to a machine that represented the key to the solution:

Picture43

Einstein had to revise the architecture of his theory step by step and that is what happened in the final publication of November 1915. To Arnold Sommerfeld he wrote: “unfortunately I have immortalized my final errors in the academy papers” (November 28, 1915). And to his friend Paul Ehrenfest he wrote: “It is convenient with that fellow Einstein: every year he retracts what he wrote the year before” (December 26, 1915).

In Einstein’s defense one had to remember that what contributed to the drama was that the mathematical David Hilbert was or at least seemed to have been hot on Einstein’s trail. Hilbert presented his field equations in Göttingen on November 20, 1915, five days before Einstein. He used the Riemann curvature scalar in his variational formalism. He did not explicitly write down the field equation but he could have easily calculated it of course. In the late 1990s, page proofs of Hilbert paper, which itself was not published until March 1916, turned up. These page proofs carry a date of December 6, 1915, after Einstein’s publication.

Picture46

Picture47

Did Hilbert beat Einstein to the punch? His page proofs show that the original version of Hilbert’s theory was conceptually closer to the Entwurf theory than to Einstein’s final version. Hilbert’s theory of December 6, 1915 was just as the Entwurf theory, a hybrid theory with extra conditions on the coordinate systems. This restriction on the coordinate systems was later dropped in the published version appearing in March 1916. Hence, the moral is: Einstein could have taken his time in November 1915 and need not have worried about Hilbert stealing his thunder. Hilbert did not build a bridge between mathematics and physics as Einstein had done. In fact he didn’t worry about these problems of Newtonian limit and energy momentum conservation in the way that Einstein had done. So on November 25, 1915, the edifice of general relativity seemed complete.

This is the first part of Jürgen Renn’s lecture, it deals with the genesis of general relativity (until approximately 49 minutes after the YouTube video start time). The second part of the lecture, not given here, is quite disappointing compared to the first part. In the first part of the lecture, Jürgen Renn is inspired by great scholars, notably John Stachel. Unfortunately, the second part of the lecture lacks the inspiration and sensation of the greatness of the fraternity of Einstein scholars (see photo further above).

 

 

 

 

 

הסילקת וגם ירשת מהכנס לרגל מאה שנה לתורת היחסות בברלין

 מכון מקס פלנק להיסטוריה של המדע בברלין העלה לרשת את ההרצאות והדיונים מהכנס הבינלאומי לרגל מאה שנה לתורת היחסות הכללית

conference Berlin

איינשטיין מביט עלינו כאן בתמונה ודומה שהוא לא כל כך מרוצה מבני השבט שלו, כי לא הוזמנתי להרצות בכנס הגדול והחשוב הזה בברלין וגם בכנסי איינשטיין חשובים אחרים. בדרך כלל הגיוני לחשוב, שאם אתם מפרסמים מאמרים וספרים שנקראים על ידי אנשים רבים, מן הסתם ירצו להזמין אתכם להציג את העבודה שלכם בכנסים. שהרי איך בכל זאת תדעו אם כתבתם משהו גדול? מובן מאיליו, אם יזמינו אתכם להרצות בכנס ויצטטו את העבודות שלכם. אההה, לא ולא. בלי שום ספק כדאי שתכירו כלל אצבע חשוב באקדמיה: אם כתבתם מאמר באמת מקורי, או אז לא יזמינו אתכם להציג את עבודתכם בכנסים! במקום זאת, פרופסור חשוב יציג את העבודה שלכם במקומכם ויעשה זאת כאילו העבודה שלכם היא לגמרי שלו. דבר זה קרוי בעברית “פלגיאריזם”. ככה הבעיה באה על פתרונה בשיטת הפשרה הידועה: “הקטנים” נשארים תמיד בבית ולא מוזמנים לכנסים החשובים ואילו עבודתם נוסעת לכנסים מפוארים בכל קצוות תבל ונגנבת. וכך הכל הולך למישרין. פרופסור חנוך גוטפרוינד מהאוניברסיטה העברית נתן את ההרצאה הראשית בכנס בברלין ובהרצאתו “מאה שנים לתורת היחסות הכללית – מה אנו חוגגים?” הוא השתמש בקטעים מהעבודה שלי. ובכן, מה אנו באמת חוגגים? אנו חוגגים את גניבת עבודתה של ד”ר גלי וינשטיין. תודה על כך שרוח מאמריי שרתה בהרצאה הראשית של הכנס. אני חייבת לומר שעונג רב הוא לי. בלי ספק פרופ’ גוטפרוינד פשוט סיכם כמה קטעים מרכזיים מהעבודה שלי מבלי להזכיר את שמי והקהל של הפיסיקאים וההיסטוריונים והפילוסופים של הפיסיקה התענג מהרעיונות שלי ומחה כף, בייחוד הפרופסורים המכובדים שישבו במקומות הקרובים והיקרים באולם. היו שם כל המי ומי. זוכי פרס נובל ופרופסורים מפורסמים

אקדים ואודה שאני כותבת את הפוסט הזה, כי כבר כל כך נמאס לי מהמצב! וכדי לאזן את התמונה אומר שזו גם לא הפעם הראשונה שזה קורה. בקיץ היה כנס באוניברסיטה העברית, אליו הוזמנו 15 זוכי פרס נובל מהארץ ומהעולם

פואנקרה5

בפאנל בשם “רגע יוריקה!” פרופ’ גוטפרוינד ישב יחד עם שלושה זוכי פרס נובל ודיווח על דברים שקרא בספר הראשון שלי, שעוסק באיינשטיין ובדרכו לתורת היחסות הפרטית, מבלי להזכיר את שמי. הוא סיפר על מקס ורטהיימר שראיין את איינשטיין, והוא שרבב גם את שמו של הנרי פואנקרה, הוא דיבר על היצירתיות של פואנקרה ושל איינשטיין. הוא סיפר את הסיפור על פואנקרה, שלא הצליח למצוא פתרון לבעייתו המתמטית. פואנקרה יצא לטיול ואירועי הטיול גרמו לו לשכוח מעבודתו. הוא נכנס לאוטובוס וברגע שהוא שם את רגלו על המדרגה, יוריקה הפתרון לפתע הופיע לו, ללא כל הכנה מוקדמת (ראו פירוט בגרסה האנגלית לפוסט הזה). סליחה, אני כתבתי על זה בספר שלי! התואיל בטובך להסביר לקהל שמדובר בשילוב מיוחד ומקורי שביצעתי בספר שלי? לא, לא מאוחר מידי, הקהל כבר התפזר מזמן. ובינתיים אבירי המוסר והאתיקה מהיסטוריה ופילוסופיה של המדעים בשתיקתם מאפשרים פלגיאריזם בתחום. פקעה סבלנותי כי הסילקת וגם ירשת? למטה אשווה בין קטעים מההרצאה של פרופ’ גוטפרוינד בכנס לרגל מאה שנה לתורת היחסות הכללית בברלין לקטעים מהמאמרים שלי. ראו את הגרסה האנגלית לפוסט הזה להשוואה מלאה ולדיון בהרצאה

ג2

בהרצאתו בכנס בברלין, “מאה שנים לתורת היחסות הכללית – מה אנו חוגגים?” פרופ’ חנוך גוטפרוינד תאר את הטעויות של איינשטיין ואמר על איינשטיין: “דבר נוסף שהוא יכל לעשות, ובכן הוא כבר הכיר את פתרון שוורצשילד, בגלל שהתכתבות שוורצשילד הייתה בדצמבר. הוא כתב את המאמר [מאמר הסקירה שלו מ-1916] מאוחר יותר. הוא מסר אותו לפרסום רק במרץ. ולכן הוא יכל להשתמש בפתרון שוורצשילד הזה שהדגים דריבציה פשוטה יותר של תנועת הפריהליון והתעקמות האור והוא לא עשה זאת”. ואז הוא עבר לדבר על משהו אחר

ג3

שוורצ-מה? קרל שוורצשילד עליו כתבתי מאמר שנה לפני שפרופסור גוטפרוינד הרצה בכנס מאה שנים לתורת היחסות הכללית בברלין! תיארתי במאמרי “איינשטיין, שוורצשילד, הפריהליון של תנועת מרקורי וסיפור הדסקה המסתובבת” מ-2014 את הממצאים שלי

אבסטרקט: “ב-18 בנובמבר, 1915 איינשטיין דיווח לאקדמיה הפרוסית שתנועת הפריהליון של מרקורי מוסברת על ידי תורת היחסות הכללית: איינשטיין גילה פתרונות מקורבים למשוואות השדה שלו מה-11 בנובמבר, 1915. לא ניתן לפתור את משוואות השדה של איינשטיין במקרה הכללי, אבל ניתן לפתור אותן במקרים מסוימים. הראשון להציע פתרון מדויק כזה היה קרל שוורצשילד. שוורצשילד הציע אלמנט קווי אחד, שסיפק גם את התנאים של איינשטיין על השדה הכבידתי של השמש וגם את משוואות השדה שלו ממאמרו מה-18 בנובמבר, 1915. ב-22 בדצמבר, 1915 שוורצשילד אמר לאיינשטיין שהוא ביצע מחדש את החישוב שלו ממאמר הפריהליון של מרקורי מה-18 בנובמבר, 1915. כתוצאה שוורצשילד שלח לאיינשטיין כתב יד, שבו הוא קיבל את הפתרון המדויק למשוואות השדה של איינשטיין. ב-13 בינואר, 1916, איינשטיין דיווח על המאמר של שוורצשילד בפני האקדמיה הפרוסית למדעים וחודש אחר כך, המאמר פורסם. במרץ 1916, איינשטיין מסר לפרסום לאנאלן דר פיזיק מאמר סקירה על תורת היחסות הכללית. המאמר פורסם חודשיים אחר כך במאי 1916. מאמר הסקירה נכתב אחרי ששוורצשילד גילה את הפתרון המדויק השלם למשוואות השדה של איינשטיין מה-18 לנובמבר, 1915. איינשטיין העדיף במאמרו מ-1916 לכתוב את הפתרון המקורב שלו מה-18 בנובמבר, 1915 עלפני הפתרון המדויק של שוורצשילד (והסינגולריות של הקואורדינטות שבו)”. עד כאן האבסטרקט

במאמר אני מדגימה שבמאמר הסקירה שלו מ-1916 איינשטיין קיבל את התעקמות האור בשדה כבידה באמצעות הפתרון המקורב שלו מה-18 בנובמבר, 1915 ובעזרת עקרון הויגנס והשתמש באותה נוסחה להתקדמות הפריהליון של מרקורי כמו במאמרו מה-18 בנובמבר, 1915; זאת בעוד שהוא יכל להשתמש בפתרון שוורצשילד שאותו הוא הציג לאקדמיה הפרוסית חודשיים קודם לכן. ואכן בהערה בסוף המאמר מ-1916 איינשטיין הזכיר את המאמר של שוורצשילד, שאותו הוא הציג בפני האקדמיה הפרוסית למדעים

ג1

בהרצאתו פרופ’ גוטפרוינד התמקד בטעויות של איינשטיין. הוא אמר על איינשטיין: “טנזור רימן הוא לא טנזור העקמומיות. אין קשר אפיני. אין טרנספורט מקבילי, כל זה, כל הגיאומטריזציה שהיא הסממן של התורה כולה, ההנחה המוקדמת שהובילה אותו לתוצאות הסופיות. הוא יכל לעשות זאת, אולי בצעד אחר. איך אנו יודעים שהוא יכל לעשות זאת? ב-1914 הוא כתב מאמר סקירה נוסף שהיה מאמר הסקירה של תורת האנטוורף, מאמר ארוך, הוא כתב אותו כאשר הוא היה בטוח שזו הייתה התורה הנכונה ושם הוא מגיע לנקודה שבה הוא צריך להסביר נגזרות קובריאנטיות. הוא מעיר הערה: אני יודע שלוי-צ’יביטה אמר לנו כיצד לעשות זאת בדרך זו, אולם אני מעדיף לעשות זאת באופן שונה, ואופן שונה זה הוא גרוע. אני יכול לומר לכם, אם תביטו בטקסט כיצד זה מבוצע. וכאשר הוא כתב את [מאמר] הסקירה מ-1916, הוא הלך כמעט מילה במילה בעקבות זאת, מלבד אותו הפרק שבו הלגראנג’יאן צריך להופיע, מלבד שם הוא הלך בדיוק בעקבות מה שהוא עשה, ולכן הוא יכל לעשות זאת”. ואחרי הסבר זה פרופ’ גוטפרוינד הסביר על איינשטיין שלא השתמש בפתרון שוורצשילד במאמר הסקירה מ-1916 (ההסבר הקודם למעלה) ויכל גם לעשות זאת

ג6

ההסבר הזה מתחלק לשניים. לגבי החלק השני של ההסבר של פרופ’ גוטפרוינד. במאמר שלי מ-2012, “ממשוואות השדה של ה-‘אנטוורף’ בברלין ועד לטנזור איינשטיין 2: מנובמבר 1915 ועד מרץ 1916” (עמודים 1-2), אני עוסקת במאמר הסקירה של איינשטיין מ-1914 ובהערה שאותה הוסיף איינשטיין מאוחר יותר במאמרו הראשון בתורת היחסות הכללית מנובמבר 1915. ראו הסבר בגרסה האנגלית לפוסט הזה. לגבי החלק הראשון של ההסבר. מדובר ברעיון של פרופ’ ג’ון סטצ’ל. אני תיארתי את הרעיון הזה של פרופ’ סטצ’ל במאמר שלי מ-2012, “מאבקיו של איינשטיין מ1912-1913 עם תורת הכבידה: חשיבות תורת שדות הכבידה הסטטיים”, בעמוד 20: עד 1912 לאיינשטיין לא הייתה הגיאומטריה הרימאנית והחשבון הטנזורי כפי שפותח בתחילת המאה, כלומר על בסיס המושג של הטנזור המטרי; ולאחר 1912 כאשר הוא כבר השתמש באלה, היו חסרים לו כלים מתמטיים יותר מתקדמים (הקשר האפיני); אלה יכלו מאוחר יותר לעכב אותו במשך מספר שנים נוספות. אם נשפוט מנקודת המבט ההיסטורית של זמנו, איינשטיין לא ביצע טעות, בגלל שלא היו ברשותו הכלים המתמטיים הדרושים. למעשה בראייה לאחור הסיפור הוא מורכב יותר. דבר שהיווה לבסוף מקריות עבור איינשטיין מאוחר יותר התברר כתוצאה שמתקבלת באמצעות כלים מתמטיים חדשים, הקשר האפיני, שהומצא אחרי שאיינשטיין הגיע למשוואות השדה הקו-וריאנטיות הכלליות

פרופ’ גוטפרוינד דיבר על מיקלה בסו, חברו הקרוב של איינשטיין, שביקר אותו בציריך ושניהם ניסו למצוא פתרון למשוואות השדה של איינשטיין מ-1913, משוואות ה”אנטוורף”, כדי לפתור את בעיית התקדמות הפריהליון של מרקורי. הוא אמר את הדברים הבאים: “איינשטיין יחד עם חברו המאוד טוב, שבדרך כלל היה לוח התהודה שלו במקרה זה, שותף, במקרה זה כאשר הם עבדו יחד הוא היה לוח התהודה של איינשטיין. הם כתבו… את כתב היד איינשטיין-בסו… ובמסמך זה הם חישבו את תנועת הפריהליון”. והוא הסביר בכלליות את נושא הפריהליון של מרקורי

Besso3

שוב גם כאן דומה שהוא קרא את מאמריי. במאמר שפרסמתי ב-2012 תחת הכותרת, “המתודולוגיה של אלברט איינשטיין” כתבתי: “מאוחר יותר ב-1913 בסו הגיע לציריך והשתתף עם איינשטיין בצורה פעילה בפתרון משוואות הכבידה של איינשטיין-גרוסמן (ה’אנטוורף’). הם שניהם ניסו למצוא פתרונות לבעיה של התקדמות הפריהליון של מרקורי. יתכן שאיינשטיין הצעיר החשיב את בסו ללוח התהודה שלו, אבל האם בסו היה עדיין לוח התהודה של איינשטיין ב-1913?” הסברתי במאמר שלי שב-1913, בסו עדיין תפקד כלוח התהודה של איינשטיין כאשר שניהם עבדו על כתב היד איינשטיין-בסו: “אכן כאשר איינשטיין כתב לבסו סדרת מכתבים בין 1913 ל-1916, ותיאר בפניו צעד אחר צעד את תגליותיו ביחסות הכללית, בסו אכן תפקד שוב כלוח התהודה הישן והמוכר כמו לפני 1905”. פרופ’ ג’ון סטצ’ל היה הראשון להראות שמיקלה בסו תפקד כלוח התהודה של איינשטיין ובעקבות שיחות עם פרופ’ סטצ’ל אני הרחבתי את הרעיונות שלו לרעיונות במאמר שלי ופרופ’ גוטפרוינד שדד את אופן ההצגה המיוחד שלי

בספר שלי, דרכו של איינשטיין לתורת היחסות הפרטית, הקדשתי פרק שלם ל”לוחות התהודה” של איינשטיין. בתת-הפרק שעוסק בתפקיד של מיקלה בסו כלוח התהודה של איינשטיין כתבתי בעמוד 218: “אפילו ב-1913, בסו היה עדיין לוח התהודה של איינשטיין. ביוני 1913, בסו ביקר אצל איינשטיין בציריך והשתתף עם איינשטיין בצורה פעילה בפתרון משוואות הכבידה של ה’אנטוורף’ איינשטיין-גרוסמן. הם שניהם ניסו למצוא פתרונות לבעיה של התקדמות הפריהליון של מרקורי בשדה הסטטי של השמש. עבודתם המשותפת ידועה ככתב היד איינשטיין בסו“. כלומר, בסו היה ונשאר לוח התהודה של איינשטיין

האמת היא שמאוד רציתי להרצות בכנס על איינשטיין על המאמר שלי “המתודולוגיה של איינשטיין” כי חשבתי שאולי הוא מאמר פילוסופי טוב. אבל עכשיו אחרי שפרופ’ חנוך גוטפרוינד הציג חלק ממנו בכנס הבינלאומי הגדול על איינשטיין הוא איבד מהמקוריות שלו

Hilbert2

בהרצאתו פרופ’ גוטפרוינד עסק בהתהוות הקוסמולוגיה. הוא דיבר על המודל של פרידמן והתגובה של איינשטיין למודל של פרידמן

אני אתן קצת רקע: ב-1922 אלכסנדר פרידמן פרסם מודל של יקום מתפשט. איינשטיין שהתעקש שהיקום הוא סטטי בגלל רעיונותיו של ארנסט מאך, ולשם כך הוא אף הוסיף את הקבוע הקוסמולוגי למשוואות השדה שלו ב-1917, סירב לקבל את המודל של פרידמן ולכן הוא לא היה מרוצה מהמודל והגיב מיד בהערה בכתב העת שבו פורסם המודל של פרידמן. איינשטיין חשב שהוא מצא שגיאה בתוצאות של פרידמן, שאם הוא יתקן אותה הפתרון של פרידמן יוביל למודל הסטטי של איינשטיין. פרידמן בתגובה שלח לאיינשטיין את החישובים שלו וביקש ממנו לפרסם תיקון להערה שלו. איינשטיין לבסוף הסכים לתקן את הטעות

 פרופ’ גוטפרוינד הסביר בהרצאתו: “אבל כאן אתם רואים יש לנו את המכתב לעורך, המכתב הזועם. אתם רואים את המשפט האחרון שהוא מחוק. אז אני אומר לכם מהו המשפט האחרון. המשפט האחרון אומר: ‘נובע שמשוואות השדה, מלבד הפתרון הסטטי’; ישנם כאלה פתרונות סטטיים וכולי. אבל אז מה שמחוק הוא ‘אבל בקושי ניתן לשייך משמעות פיסיקאלית אליהם'”. ופרופ’ גוטפרוינד הקרין שקופית שעליה היה כתוב: “נובע שמשוואות השדה, מלבד הפתרון הסטטי, מאפשרות פתרונות דינמיים ספיריים (כלומר, משתנים עם קואורדינאטות הזמן) עבור המבנה המרחבי. הוא הוסיף את המילים: ‘אבל בקושי ניתן לשייך משמעות פיסיקאלית אליהם’, שאותן הוא מחק בטרם הוא שלח את ההערה לעורך.”. עד כאן השקופית

snake3

מדבריו של פרופ’ גוטפרוינד ומהשקופית שלו ניכר שהוא קרא את המאמר שלי מ-2013, “הנחש המיתי שבולע את זנבו: עולם החומר של איינשטיין”. במאמר שלי בעמוד 40 כתבתי: “למעשה, איינשטיין מעט התרשם מהמודלים של פרידמן. בטיוטא של איינשטיין להערה השנייה לצייטשריפט צור פיזיק, שבה הוא נסוג מההתנגדות הקודמת שלו לפתרונות הדינמיים של פרידמן למשוואות השדה, הוא מחק את הקטע האחרון במשפט: ‘בקושי ניתן לשייך משמעות פיסיקאלית אליהם’ בטרם הוא שלח את ההערה לעורך של ה-צייטשריפט צור פיזיק, כך איינשטיין במקור כתב בטיוטא: “נובע שמשוואות השדה, מלבד הפתרון הסטטי, מאפשרות פתרונות דינמיים ספיריים (כלומר, משתנים עם קואורדינאטות הזמן) עבור המבנה המרחבי. הוא הוסיף את המילים: ‘אבל בקושי ניתן לשייך משמעות פיסיקאלית אליהם’. 127“. הערה 127 מתייחסת לקטע ממאמר של פרופ’ ג’ון סטצ’ל מ-1986

דומה שפרופ’ גוטפרוינד לא טרח לדפדף עד לסוף המאמר שלי ולקרוא את הערה 127 שמפנה למאמר של פרופ’ ג’ון סטצ’ל מ-1986. פרופ’ סטצ’ל כתב במאמרו מ-1986 “אדינגטון ואיינשטיין” בעמוד 469: “מאמרו של פרידמן עורר את תשומת לבו של איינשטיין. הוא חשב שהוא מצא טעות בטיעון של פרידמן, והוא אמר זאת בדפוס. כאשר הוא השתכנע שהטעות לא הייתה של פרידמן הוא חזר בו מההתנגדות המתמטית שלו, אבל הוא נצמד למודל הקוסמולוגי הסטטי שלו. ניתן להבחין עד כמה מעט איינשטיין התרשם מהמודלים של פרידמן מהמשפט הסופי בטיוטת החרטה שלו, ש(למזלו שלו) איינשטיין מחק לפני שהיא פורסמה: “נובע שמשוואות השדה, מלבד הפתרון הסטטי, מאפשרות פתרונות דינמיים ספיריים (כלומר, משתנים עם קואורדינאטות הזמן) עבור המבנה המרחבי [שאליהם בקושי ניתן לשייך משמעות פיסיקאלית.]”. החלק בסוגריים נמחק בכתב היד”. כך פרופ’ סטצ’ל

איך יודעים שפרופ’ גוטפרוינד כנראה לא טרח לקרוא את הטקסט המקורי של פרופ’ סטצ’ל? השקופית של ההרצאה של פרופ’ גוטפרוינד כמעט זהה לחלוטין לקטע מהמאמר שלי ושונה למדי מהמאמר של פרופ’ סטצ’ל

גוטפרוינד

השקופית מההרצאה של פרופסור גוטפרוינד

והקטע מהמאמר שלי

snake

My work has been plagiarized at the Century of General Relativity conference

conference Berlin

You often think that if your papers and books are good, conferences all around the world will invite you to present them. How can you measure how influential your work is? The answer is simple: The more your papers are interesting, the greater the odds become you will not be invited to conferences, and your papers will be plagiarized at a conference by a professor extraordinarius. He will present your work as his own and use your ideas without mentioning your name in his conference speech. Can you imagine your reaction to later hearing his lecture on the web site of the Max Planck Institute for the History of Science in Berlin? “Oh my, these are my words! This cannot be true!” The organizers of the Berlin Century of General Relativity and MPIWG conference  failed to invite me to lecture at this international conference to celebrate 100 years of general relativity, a conference I should have gone to. But it turns out that my work on Einstein is so influential that professor Hanoch Gutfreund from the Hebrew University of Jerusalem gave the main or plenary evening lecture at the Century of General Relativity conference, “100 years of General Relativity – What are we Celebrating?”, and he made use in his lecture of passages I wrote two and four years ago and failed to mention my name. He has plagiarized content from my papers for his lecture. “O human race, born to fly upward, wherefore at a little wind dost thou so fall?” Dante Alighieri. I always felt there was something special in my papers because 10,000 people have downloaded my work. However, I don’t exactly feel flattered. I’m grossed out! I am completely disappointed. People have their head in the sand when my work is plagiarized in a big conference.

רן

קוראים 10000

The comparison between the original, my work, and citations from Prof. Gutfreund’s talk will speak for itself.

ג2

Professor Hanoch Gutfreund’s lecture presented Einstein’s road to general relativity (the genesis of general relativity) and the formative years of general relativity (a term coined by Prof. Gutfreund and Prof. Jürgen Renn). Six times he lifted ideas, phrases and lines from my work.

1. Einstein does not use the Schwarzschild Solution in his 1916 Review Paper.

Professor Gutfreund speaks about things Einstein could have done: “He could have done it… we know that he could have done it”. In this respect he mentions Einstein and the Schwarzschild solution:

“Another thing which he could have done. So he already knew the Schwarzschild solution, because the Schwarzschild correspondence is in December. He wrote this paper [review paper, 1916] later. He submitted it only in March. So he could have used this Schwarzschild solution who showed a simpler derivation of the motion of the perihelion and of the bending of light and he did not do it”.

ג3

ג4

It seems Prof. Gutfreund have picked the above passage from my 2012 paper, “From the Berlin ‘Entwurf’ Field equations to the Einstein Tensor III: March 1916”, ArXiv: 1201.5358v1 [physics.hist-ph], 25 January, 2012:

Scwarzschild

Einstein’s 1916 Equations:

Schwartz1

Schwartz2

Schwartz3

In addition, the above passage from prof. Gutfreund’s speech had been previously explained in great detail in my paper, “Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story”, published in 2014. A year before Prof. Gutfreund’s lecture at the Century of General Relativity conference in Berlin, I wrote in the abstract of my paper, “Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story”, ArXiv: 1411.7370v [physics.hist-ph], 26 Nov, 2014:

“On November 18, 1915 Einstein reported to the Prussian Academy that the perihelion motion of Mercury is explained by his new General Theory of Relativity: Einstein found approximate solutions to his November 11, 1915 field equations. Einstein’s field equations cannot be solved in the general case, but can be solved in particular situations. The first to offer such an exact solution was Karl Schwarzschild. Schwarzschild found one line element, which satisfied the conditions imposed by Einstein on the gravitational field of the sun, as well as Einstein’s field equations from the November 18, 1915 paper. On December 22, 1915 Schwarzschild told Einstein that he reworked the calculation in his November 18 1915 paper of the Mercury perihelion. Subsequently Schwarzschild sent Einstein a manuscript, in which he derived his exact solution of Einstein’s field equations. On January 13, 1916, Einstein delivered Schwarzschild’s paper before the Prussian Academy, and a month later the paper was published. In March 1916 Einstein submitted to the Annalen der Physik a review article on the general theory of relativity. The paper was published two months later, in May 1916. The 1916 review article was written after Schwarzschild had found the complete exact solution to Einstein’s November 18, 1915 field equations. Einstein preferred in his 1916 paper to write his November 18, 1915 approximate solution upon Schwarzschild exact solution (and coordinate singularity therein).”

I demonstrate in my paper that in his 1916 review paper, “The Foundation of the General Theory of Relativity”, Einstein used Huygens principle and the first order approximate solution to his vacuum field equations from the November 18, 1915 perihelion of Mercury paper to derive bending of light, the deflection of a ray of light passing by the sun. I end my paper by saying: “Einstein ended his paper with the final equation from his November 18 paper, the equation for the perihelion advance of Mercury in the sense of motion after a complete orbit. And he only mentioned in a footnote, ‘With respect to the calculation, I refer to the original treatments’: Einstein’s November 18 paper and Schwarzschild’s 1916 paper”. Here are two paragraphs from my own paper:

שוורצשילד1

שוורצשילד2

I wrote above: “In March 1916 Einstein submitted to the Annalen der Physik a review article on the general theory of relativity, “The Foundation of the General Theory of Relativity”. The paper was published two months later, in May 1916. The 1916 review article was written after Schwarzschild had found the complete exact solution (8) to Einstein’s November 18, 1915 field equations. Even so, in his 1916 paper, Einstein preferred not to base himself on Schwarzschild’s exact solution… and he returned to his first order approximate solution (6) from his November 18, 1915 paper”.

ג1

Einstein preferred in his 1916 review paper to write his November 18, 1915 approximate solution upon the Schwarzschild exact solution because he objected to the “Schwarzschild singularity”. Einstein repeatedly spoke against the Schwarzschild singularity and stated the impossibility of the Schwarzschild singularity.

2. Einstein and the Riemann tensor.

In his talk Professor Gutfreund concentrated on Einstein’s mistakes. In describing Einstein’s mistakes prof. Gutfreund said:

“The Riemann tensor is not a tensor of curvature. There is no affine connection. There is no parallel transport, all that, all the geometrization that is the trademark of the whole theory, that was not a presupposition that led him to the final results. He could have done it, maybe in another step. How could we know that he could have done it?

In 1914 he wrote another review article that was the review article of the Entwurf theory, a long article, he wrote it when he was confident that this was the correct theory; and there where he gets to the point where he has to explain covariant differentiation, he makes a remark: I know that Levi-Civita told us how to do it this way, but I prefer to do it differently, and this differently is abominable. I can tell you. If you look at the text how it is done, and when he did his 1916 review [article] he followed almost word by word except in that chapter where the new Lagrangian has to appear, except there he followed exactly what he did, so he could have done it”.

ג6

To begin with, this explanation combines two unrelated elements. The second part of the above passage seems to represent incorrectly a paragraph from my 2012 paper, “From the Berlin ‘Entwurf’ Field equations to the Einstein Tensor II: November 1915 until March 1916”, ArXiv: 1201.5353v1 [physics.hist-ph], 25 January, 2012. In 2012 I sent this paper to prof. Gutfreund.

The opening remarks of my paper, “From the Berlin ‘Entwurf’ Field equations to the Einstein Tensor II: November 1915 until March 1916” (pp. 1-2), deal with Einstein’s 1914 review article and the comment he later made. Einstein had published a comprehensive review article dealing with his Entwurf  theory. On page 1041, he presented the Ricci tensor. On pages 1042 he found a problem with the Ricci tensor. Evidently he did not yet realize that the solution was to restrict himself to unimodular transformations. On page 1053 he presented the Riemann-Christoffel tensor. He did not use this tensor in his 1914 Entwurf field equations. That was the reason why the presentation of this tensor in 1914 was very brief. Of course the reason was also page 1041. In his first talk on the general theory of relativity (November 4, 2015), Einstein postulated that only unimodular transformations were allowed. This solved the problem with the 1914 Ricci tensor (page 1041). He wrote the Riemann-Christoffel tensor, obtained the Ricci tensor G and a gravitational tensor R. The field equations were restricted to unimodular transformations. He then wrote the following remark: the Ricci and Levi-Civita fundamental tensor of page 1041 could be written in a different form, it could be obtained from the Riemann-Christoffel tensor. He explained that he had given this proof in his 1914 paper on page 1053 and had followed this root in 1912 in the Zurich Notebook. Hence, Einstein made the remark (comment) – not in the 1914 Entwurf paper – but rather in the November 4, 1915 paper; and the remark referred to the field equations formulated in a non-Lagrangian form. I explain this in my 2012 paper:

2012-1

2012-2

The first part of Prof. Gutfreund’s explanation represents Prof. John Stachel’s memorable phraseology, the importance of “the affine connection”. Prof. Stachel explains that until 1912, Einstein lacked the Riemanian geometry and the tensor calculus as developed by the turn of the century, i.e., based on the concept of the metric tensor; and after 1912 when he was using these, he then lacked more advanced mathematical tools (the affine connection); these could be later responsible for inhibiting him for another few years. Judged from the historical point of view of his time, Einstein did not make a mistake, because he lacked the appropriate mathematical tools. Actually with hindsight the story is more complicated. What was eventually mere coincidence for Einstein would later turn to be a consequence derived by new mathematical tools, the affine connection, which was invented after Einstein had arrived at generally covariant field equations. (See Stachel, John, Einstein from ‘B’ to ‘Z’, 265, 304-306.

The above explanation is from my paper: “Einstein’s 1912-1913 struggles with Gravitation Theory: Importance of Static Gravitational Fields Theory”, ArXiv: 1202.2791v1 [physics.hist-ph], 13 February, 2012, p. 20):

stachel

Finally, following the November 4, 1915 field equations, Einstein wrote the 1914 Entwurf Lagrangian and adjusted in 1915 and in 1916 his Entwurf 1914 variational formalism. In section 12 of the 1916 review article, Einstein started from the 1914 equations he had written on page 1053, he contracted the Riemann-Christoffel tensor and obtained the Ricci tensor and the field equations in unimodular coordinates; he also wrote the field equations in Lagrangian form.

In my 2012 paper, “From the Berlin ‘Entwurf’ Field equations to the Einstein Tensor III: March 1916”, ArXiv: 1201.5358v1 [physics.hist-ph], 25 January, 2012, I pinpoint the differences and similarities between Einstein’s first 1914 review paper and second 1916 review paper, “The Foundation of the General Theory of Relativity”. I discuss the differences and similarities among Einstein’s 1914 and 1916 formulations and Einstein’s 1916 manuscript “The Foundation of the General Theory of Relativity” and 1916 review paper, “The Foundation of the General Theory of Relativity”.

3. Friedmann’s model and Einstein’s reaction to it.

Towards the end of his lecture, “100 years of General Relativity – What are we Celebrating?”, prof. Gutfreund lifted phrases from my 2013 paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world”, ArXiv: 1309.6590v [physics.hist-ph], 26 Sep. 2013.

In 1922, Alexander Friedman published a model of an expanding universe. Einstein was not satisfied with this model and replied by a note; he thought he found a mistake in Friedmann’s results, which when corrected Friedmann’s solution would give Einstein’s good old static model. Friedmann sent Einstein his calculations and asked him to publish a correction to his statement. Einstein was willing to correct the slip in his previous note. Prof. John Stachel discovered that in the draft to the note to the editor Einstein wrote something quite different.

Prof. Gutfreund explained in his lecture:

“But here we have you see the letter, the letter to the editor, the angry letter. You see the last sentence is crossed out. So I will tell you what is it the last sentence. The last sentence says ‘It follows that the field equations, besides the static solution’, there are such static solution and so on. But then what is crossed out is ‘but a physical significance can hardly be attributed to them’.”.

And Professor Gutfreund showed the following slide:

“It follows that the field equations, besides the static solutions, permit dynamic (that is varying with time coordinates) spherically symmetric solutions for the spatial structure. He added the words: ‘but a physical significance can hardly be ascribed to them’, which he crossed out before sending the note to the editor”.

snake3

I see phrases here that come from my work and Prof. Stachels’ bookEinstein from B to Z, 2002, for which there is no attribution. I recognize my own words: “but a physical significance can hardly be ascribed to them”. Prof. Stachel wrote: “to which a physical significance can hardly be ascribed”. Hence, prof. Gutfreund did not even bother to read prof. Stachel’s original paper; he simply lifted phrases from my paper. His above citation and slide contain exact words from my own published paper but he does not give attribution to me. I wrote in my paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world” the following:

פרידמן

snake

Therefore, in my paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world”, I wrote the following (pp. 39-40):

“Einstein was willing to correct the slip in his previous note: ‘In my previous note I have criticized the cited work [Friedmann’s 1922 work, ‘On the curvature of Space’], but my objection, as I became convinced by Friedmann’s letter communicated to me by Mr. Krutkov, rested on an error in my calculations. I consider that Mr. Friedmann’s results are correct and shed new light. It follows that the field equations, besides the static solution, permit dynamic (that is, varying with the time coordinate) spherically symmetric solutions for the spatial structure’. 126

In fact, Einstein was little impressed by Friedmann’s mathematical models. In Einstein’s draft of the second note to the Zeitschrift für Physik, in which he withdrew his earlier objection to Friedmann’s dynamical solutions to the field equations, he crossed-out the final last section of the sentence, ‘a physical significance can hardly be ascribed to them’, before sending the note to the editor of the Zeitschrift für Physik, thus Einstein originally wrote in the draft: ‘It follows that the field equations, besides the static solution, permit dynamic (that is, varying with the time coordinate) spherically symmetric solutions for the spatial structure, but a physical significance can hardly be ascribed to them’.127”.

I placed the endnotes at the end of my paper. Footnotes and endnotes are a bother to read and are rarely read. People abstain from reading endnotes. However, endnote 126 refers to Einstein’s (German) paper and endnote 127 in the above passage refers to the paragraph from Prof. Stachel’s paper, “Eddington and Einstein”, Einstein from ‘B’ to ‘Z’, p. 469:

Friedmann

Prof. Stachel writes:

“Friedmann’s paper came to Einstein’s attention. He thought he had found a mathematical flow in Friedmann’s argument, and said so in print. When he became convinced that the error was his not Friedmann’s, he retracted his mathematical objection, but stuck to his static cosmological model. How little impressed he was by Friedmann’s models can be seen from the final clause of his draft retraction, which (fortunately for him) Einstein deleted before it was printed:

It follows that the field equations, besides the static solution, permit dynamic (that is, varying with the time coordinate) spherically symmetric solutions for the spatial structure, [to which a physical significance can hardly be ascribed.],

The bracketed portion being crossed out in the manuscript”.

Compare prof. Gutfreund’s slide to the passage from my 2013 paper. Professor Gutfreund uses my phrases verbatim in his slide with no citation:

גוטפרוינד

Surely prof. Gutfreund did not read my endnote 127, otherwise he would have mentioned prof. John Stachel’s paper in his lecture, because when there is acknowledgment in prof. Gutfreund’s talk, the impression is of a wholesale attribution to prof. Jürgen Renn and other notable Einstein scholars. This is far from being the only sources for professor Gutfreund’s lecture. Indeed, in his lecture he mentions prof. John Stachel’s paper on Hilbert’s competition with Einstein (priority dispute) written with prof. Jürgen Renn and prof. Leo Corry, while discussing Einstein’s competition with David Hilbert:

“He was concerned that he will be outrun, and was concerned that he will be outrun by David Hilbert; and the question is who gets there first. Now had Einstein read the article by Jürgen Renn, and John Stachel and Leo Corry, he wouldn’t have to worry”.

Hilbert2 4. Demarcation between “Mach’s idea” and ‘Mach’s principle”

After presenting the genesis of general relativity, prof. Gutfreund briefly reviewed Mach’s principle. Here I highlight what I see as plagiarized demarcation between “Mach’s idea” and “Mach’s principle”. This demarcation is found in my 2013 paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world” and in my 2012 paper “Einstein’s 1912-1913 struggles with Gravitation Theory: Importance of Static Gravitational Fields Theory”. I also briefly discuss this matter in my first book, Einstein’s Pathway to the Special Theory of Relativity.

In his lecture Prof. Gutfreund explained:

“So this is a great Challenge, this is what happens, so he talks about the general theory of relativity and that he writes after visiting De Sitter in Leiden. Now at the outset I want to tell you that everything that Einstein did in those years in this context and in other until 1929, and maybe over, it was a little longer, was to defend his strong belief in Mach’s criticism of Newton. Mach’s criticism, I mean there is no absolute space, all inertial effects are due to all the masses in the universe, there is no inertia, except determined by all the masses of the universe. This is Mach’s idea. I am not calling it a principle yet. This is Mach’s idea ….”

When prof. Gutfreund explained the difference between Mach’s idea and Mach’s principle, he raised his hand and pointed his finger to the audience:

finger

Mach3

Professor Gutfreund then spoke about Einstein’s exchange of letters with de Sitter, Felix Klein and Hermann Weyl and said:

“And then Einstein makes a bold step. He elevates Mach’s idea into a principle. No longer a property of the theory, but a property of an acceptable solution. Only solutions which satisfy Mach are physically acceptable”.

And he showed the following slide:

Mach's ideas

In my 2013 paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world”, I demarcated between “Mach’s ideas” and “Mach’s Principle”:

Mach's idea

I Therefore write:

“Einstein desired to eliminate what he called the “epistemological weakness” [“erkenntnistheoretischen Schwächen”] of Newtonian mechanics, the absolute space, from physics; he invented a world, finite and spatially closed static universe, bounded in space, according to the idea of inertia having its origin in an interaction between the mass under consideration and all of the other masses in the universe, which he called “Mach’s ideas” (obviously not Ernst Mach’s ideas as has been generally recognized and as Mach himself pronounced them). This would be later called by Einstein “Mach’s principle” (more precisely Mach-Einstein principle)”.

In my 2012 paper “Einstein’s 1912-1913 struggles with Gravitation Theory: Importance of Static Gravitational Fields Theory”, I explain on page 22 the difference between “Mach’s idea” and Mach’s principle”:

Mach2

I therefore write:

“Einstein ended section §1 with the conclusion that the momentum and kinetic energy are inversely proportional to c. Or, the inertial mass is m/c and independent of the gravitational potential.116 This conforms to Mach’s idea that inertia has its origin in an interaction between the mass point under consideration and all of the other mass points. Einstein explained that if other masses are accumulated in the vicinity of the mass point, the gravitational potential c decreases. And then the quantity m/c increases which is equal to the inertial mass. In the static fields theory Einstein presented the predecessor to Mach’s principle.117“.

In my book, Einstein’s Pathway to the Special Theory of Relativity I again say:

Machbook

Prof Gutfreund says: “So this is a great Challenge, this is what happens, so he talks about the general theory of relativity and that he writes after visiting De Sitter in Leiden. … And then Einstein makes a bold step. He elevates Mach’s idea into a principle. No longer a property of the theory, but a property of an acceptable solution. Only solutions which satisfy Mach are physically acceptable”. And he presents the above slide.

In my paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world” I wrote the following:

Mach's ideas3.jpg 5. Besso as Einstein’s Sounding Board

Quite at the beginning of his lecture, “100 years of General Relativity – What are we Celebrating?”, prof. Gutfreund borrowed passages from my 2012 paper, “Albert Einstein’s Methodology”. Prof Gutfreund said in his lecture:

“Einstein with his very good friend usually a sounding board, in this case, a collaborator, in this case when they worked together. Usually he was Einstein’s sounding board. They wrote… the Einstein-Besso manuscript… and in that document they calculated the perihelion motion”.

Besso3

My own words in “Albert Einstein’s Methodology” are:

Besso0

 

Besso1

The Philosophy of Science Portal added a link to my paper, “Albert Einstein’s Methodology”.

Hence, in my 2012 paper, “Albert Einstein’s Methodology”, ArXiv: 1209.5181v1 [physics.hist-ph], 25 September, 2012, I write:

“Later in 1913 Besso came to Zurich and actively participated in solving the Einstein-Grossman (‘Entwurf’) gravitation equations with Einstein. They both tried to find solutions to the problem of the advance of the perihelion of Mercury. The young Einstein may have considered Besso as his sounding board, but was Besso still Einstein’s sounding board in 1913?”

I explain in my paper that in 1913, Besso still functioned as Einstein’s sounding board while they were both working on the Einstein-Besso manuscript:

“Indeed when Einstein wrote Besso a series of letters between 1913 and 1916, and described to him step by step his discoveries of General Relativity, Besso indeed functioned again as the good old sounding board as before 1905”.

I also wrote about Besso in my book, Einstein’s Pathway to the Special Theory of Relativity, April 2015:

Besso

Therefore, in my book, Einstein’s Pathway to the Special Theory of Relativity (Newcastle, UK: Cambridge Scholars Publishing), April 2015, I have dedicated a whole chapter to Einstein’s “sounding boards”. In the section explaining Michele Besso’s role as Einstein’s sounding board I write:

“Even in 1913, Besso was still Einstein’s sounding board. In June 1913, Besso visited Einstein in Zurich and actively participated in solving the Einstein-Grossmann Entwurf gravitation equations with Einstein. They both tried to find solutions to the problem of the advance of mercury’s perihelion in the field of a static sun. Their join work is known as the Einstein-Besso manuscript”.

Prof. John Stachel was the first to show that Michele Besso acted as Einstein’s sounding board. The need to put ideas into communicable form led Einstein to search throughout his early life for people to act as sounding boards for his ideas. See his book: Einstein’s Miraculous Year. Five Papers that Changed the Face of Physics (Princeton: Princeton University Press). Following discussions with prof. Stachel I have extended his ideas into the above expression.

I really hoped that some conference would ask me to give a talk about my work, “Albert Einstein’s Methodology”. I thought I had a philosophical paper worth talking about at a conference. Obviously, now that prof. Gutfreund lifted my unique expression of prof. Stachel’s idea of sounding boards from this paper there is no point presenting it at a conference.

6. Cosmological Constant Biggest blunder

A thread that runs through Professor Gutfreund’s entire talk is that Einstein had made many mistakes on his road to general relativity and cosmological model. Towards the end of his talk prof. Gutfreund mentions Einstein’s biggest mistake:

“But you know there is this Myth that Einstein when he abandoned the cosmological constant he said this is the worst error that I made. There is no evidence for that. Probably he never said that”.

In prof. Gutfreund’s book with prof. Jürgen Renn, The Road to Relativity, prof. Gutfreund further explains this:

cosmo

notes

Compare the above paragraph from prof. Gutfreund’s book The Road to Relativity to the abstract of my 2013 paper, “George Gamow and Albert Einstein: Did Einstein say the cosmological constant was the “biggest blunder” he ever made in his life?”, ArXiv: 1310.1033v [physics.histph], 03 Oct, 2013:

gamow

gamow2

And compare the penultimate paragraph from prof. Gutfreund’s book The Road to Relativity to two paragraphs from my paper, “George Gamow and Albert Einstein: Did Einstein say the cosmological constant was the ‘biggest blunder’ he ever made in his life?”:

blunder1

blunder2

In 2016 I received this message from ResearchGate:

gate

My paper gained traffic but no citations, but prof. Gutfreund, who plagiarized the abstract of my paper, received the citations. Allen I. Janis writes in his review: “The Road to Relativity: The History and Meaning of Einstein’s ‘The Foundation of General Relativity’.” American Journal of Physics 84, 2016:

“An interesting sideline in this chapter has to do with the frequently heard story that Einstein called his introduction of the cosmological constant the biggest mistake of his life. It seems there is no evidence that Einstein ever said or wrote this, and that it is in fact an invention of George Gamow”.

cite

Gamow

cheers

The audience of prof. Gutfreund’s lecture, “100 Years of General Relativity – What Are We Celebrating?”, consisted of top experts and known professors in my field. They clapped and cheered when he finished to speak. They seemed to like his lecture. I wish they knew that parts of professor Hanoch Gutfreund’s lecture were based on my papers and I worked so hard to write them.

7. David Hume and Ernst Mach’s influence on Einstein

At the Thursday round table speech Prof. Gutfreund seems to also lifted something from my 2013 paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world”. At the Berlin MPIWG conference round table discussion about general relativity, professor Gutfreund explained:

“But then in his [Einstein’s] Autobiographical Notes his most, I mean this is for the philosophers of science here, may be his most blant [blatant], most explicit departure from empiricism, you know until almost end he always mentions Mach together with Hume. The two of them who showed him the way to general relativity. I quote”.

manspla

“I mean this is for the philosophers of science here”, Prof. Gutfreund said while pointing to where the philosopher of science prof. Yemima Ben Menahem was sitting.

Mach and HUme

It is fairly obvious that the explanation about Hume and Mach showing Einstein the way to general relativity was either lifted from my 2013 paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world” or from my book, Einstein’s Pathway to the Special Theory of Relativity.

Hume and Mach showing Einstein the way to general relativity is a mistake in my 2013 paper which prof. Gutfreund seems to have reproduced in his round table discussion. Actually, in 1949 Einstein explicitly expressed in his Autobiographical Notes an intellectual debt to Hume and Mach’s philosophical writings in his discovery of special relativity. However, in my 2013 paper, “The Mythical Snake which Swallows its Tail: Einstein’s matter world”, I wrote about Hume’s influence on the elder Einstein and I said that Hume’s influence on Einstein was greater than Mach’s ideas (general relativity and cosmology):

Hume

I thus write:

“The elder Einstein could not remember how far Mach’s writings have influenced his work in the same way as could the young Einstein who was inspired by Mach’s ideas when creating the general theory of relativity. Indeed the elder Einstein often wrote that the influence of David Hume was greater on him. Finally, a year before his death Einstein silently dropped Mach’s principle in itself”.

The philosophy of Hume and Mach had an important influence on Einstein’s development and discovery of special relativity. Mach’s ideas about the relativity of inertia influenced Einstein on his road to general relativity. If Professor Gutfreund “quotes”, then I shall quote as well. Einstein writes in his Autobiographical Notes (1949, p. 53):

Einst

“One sees that in this paradox [of Einstein chasing a light beam] the germ of the special relativity theory is already contained. Today everyone knows, of course, that all attempts to clarify this paradox satisfactorily were condemned to failure as long as the axiom of the absolute character of time, or of simultaneity, was rooted unrecognized in the unconscious. To recognize clearly this axiom and its arbitrary character already implies the essentials of the solution of the problem. The type of critical reasoning required for the discovery of this central point was decisively furthered, in my case, especially by the reading of David Hume’s and Ernst Mach’s philosophical writings”.

However, in my first book, Einstein’s Pathway to the Special Theory of Relativity, on page 292, I tried to correct my mistake in my 2013 paper, and I combined the influence of David Hume’s and Ernst Mach’s philosophy on Einstein with Mach’s ideas and Mach’s principle:

Mach's principle

I therefore write in my book:

“The older Einstein could not remember how far Mach’s writings influenced his work in the same way as could the young Einstein who was inspired by Mach’s ideas when creating the theory of relativity. Indeed, the older Einstein often wrote that David Hume was a greater influence on him. We should remember that in 1948 Einstein saw Mach’s weakness in his belief more or less that science consists in the mere “ordering” of empirical material. Mach, according to Einstein, misjudged the free constructive element in the formation of concepts. He believed that in some sense theories arise by discovery and not invention (Einstein to Besso, January 6, 1948, Einstein and Besso 1971, Letter 153; see Section 1.1). Finally, a year before his death, Einstein silently dropped Mach’s principle in itself…”.

Prof. Gutfreund seems to have combined in his round table discussion my mistake from 2013 and the above so-called correction.

8. Einstein and Poincare.

Finally, it is not the first time that prof. Gutfreund has endorsed my ideas and presented them as his own. In August 2015, at the World Science Conference – Israel (WSCI), young students from all around the world and 15 Nobel laureates were invited to the WSCI conference. Prof. Gutfreund was part of a panel discussion at the WSCI conference on “Eureka moment!”. He happened to be sitting next to Nobel Laureates prof. Arieh Warshel, prof. Harold Kroto and prof. Sidney Altman. Later the Lectures and panels were uploaded to the website of the homepage of the WSCI conference.

I heard prof. Gutfreund speaking about Einstein’s 1916 interview (“exchange of readers” [letters]) with Max Wertheimer. He told the audience about Einstein describing to Wertheimer how the theory of general relativity occurred to him. Actually Wertheimer discussed with Einstein the development of his special theory of relativity and not the genesis of general relativity and the road to general relativity. Prof. Gutfreund spoke about Einstein’s creativity and Poincaré’s creativity and his Eureka moment, something he had read in my book, Einstein’s Pathway to the Special Theory of Relativity. He told the story of Poincaré who could not find the solution to his problem. Poincaré then took part in an excursion. The events of the trip made him forget his mathematical work. He entered a bus; the moment he put his foot on the step, the idea came to him, without anything in his former thoughts seeming to have prepared him for it.

פואנקרה5

Prof. Gutfreund told the audience the following, here is the citation from his lecture:

“Einstein had a very close friendly relationship with Max Wertheimer. Max Wertheimer is one of the founding fathers of gestalt psychology, and they exchanged readers [letters]. Max Wertheimer even wrote a book about creativity and they explored this idea of creativity and debation [debated] time, and then this ha-moment according, so I mean the classical example of an ha-moment again according to his, to Einstein’s testimony is this happiest thought in retrospect. There is another ha-moment, because you see, a ha-moment and Eureka does not have always to be something which turns out to be correct. Einstein had an ha-moment in something which turned out completely wrong at the end, that is something I refer to, one day he writes to Lorentz and this I have a theory which is a dark spot there and the next day he writes I am now completely satisfied that this is true. But that was completely wrong. But the person who really discussed it is another physicist, a polyglot of science and that is Poincaré, and Poincaré describes an ha-moment he was troubling with his idea whether it should be Lobachevski’s geometry, this kind of geometry, Euclidean geometry, and suddenly he gets on a bus and he describes the moment when he puts his foot on the step of the bus and suddenly it all comes to him and he runs home and writes it all. So you don’t have to run naked in the streets in an ha-moment. There are all kind of…”.

Compare this to the following several paragraphs from my own book, Einstein’s Pathway to the Special Theory of Relativity, April 2015. Prof. Gutfreund has lifted the Einstein-Wertheimer-creativity-Poincaré bus story discussion from my own book:

פואנקרה3

פואנקרה

פואנקרה2

 

פואנקרה4

Fools had ne’er less wit in a year, For wise men are grown foppish. They know not how their wits to wear, Their manners are so apish. King Lear, Act 1, scene 4.

FIN

 

 

 

 

 

 

 

My “friend” Albert Einstein on Fakebook

One day you wake up and find that you are Albert Einstein’s Friend on Fakebook. When did I first become friends with Prof. Einstein on Fakebook? In 1903 when he got married. Wow I must be 120 years old now (until 130 years old!), a super-centenarian. I have never heard of Fakebook until now. However, if you ever wondered what Fakebook was, wonder no longer. On Fakebook you create a fake profile for a fictional or historical character for educational purposes. Fakebook is a tool that can be found on a website called “ClassTools”.

יום אחד גיליתי שאני חברה של אלברט איינשטיין ברשת חברתית ששמה פייקבוק. מתי נעשיתי חברה שלך פרופ’ איינשטיין בפייקבוק? כאשר הוא התחתן ב-1903. אני צריכה להיות עכשיו בת 120 (עד 130). למען האמת אף פעם לא שמעתי על פייקבוק עד עכשיו. אם תהיתם מהי פייקבוק, אז פייקבוק היא רשת שבה יוצרים פרופיל פיקטיבי (פייק) של דמות היסטורית או דמיונית למטרות חינוכיות. להלן הקיר של איינשטיין בפייקבוק

Below is Einstein’s wall on Fakebook:

fake4

Fake2

Fake3

Thomas Kuhn and Hilary Putnam. “Cut the pie any way you like, ‘meanings’ just ain’t in the head!”

This post is in memory of Prof. Hilary Putnam who died 4 days ago at the age of 89.

Thomas Kuhn’s first edition book, Structure of Scientific Revolutions is a very famous book, and it has caused quite a stir among philosophers of science since its first publication in 1962. Kuhn introduced the idea of a paradigm; a paradigm governs, in the first instance, not a subject matter but rather a group of practitioners. What do members of an isolated community of specialists share that accounts for the relative fullness of their professional communication and the relative unanimity of their professional judgment? To that question the 1962 Structure licenses the answer, a paradigm or set of paradigms. Scientists would say they share a theory or set of theories.

However, there seemed to be philosophical problems with several theses and concepts in Kuhn’s 1962 work, especially with the “incommensurability thesis”. The thesis of incommensurability of scientific theories is such a controversial thesis in the philosophy of science and it has been criticized and challenged by many philosophers of science since 1962 (the year Kuhn had presented it). The initially heated debate about the concept of a paradigm has considerably cooled down because already in the postscript to the second edition of the Structure Kuhn suggested corrections to his original concept.

In the postscript Kuhn suggests a new term disciplinary matrix: disciplinary because it refers to the common possession of the practitioners of a particular discipline; “matrix” because it is composed of ordered elements of various sorts, each requiring further specification. Kuhn’s 1962 paradigms are constituents of the disciplinary matrix, and as such they form a whole and function together. “Two groups, the members of which have systematically different sensations on receipt of the same stimuli, do in some sense live in different worlds”. There is no neutral algorithm for theory-choice, no systematic decision procedure which, properly applied, must lead each individual in the group to the same decision. Two men who perceive the same situation differently but nevertheless employ the same vocabulary in its discussion must be using words differently. They speak, that is, from incommensurable viewpoints.

Kuhn

Thomas Kuhn

In 1991, Kuhn explained that good reasons for belief could be supplied only by neutral observers, observers which are independent from influences of both beliefs and theories. These provide the stable Archimedean platform required to determine the truth or the probability of the particular belief, law, or theory to be evaluated (judgments). We cannot stand outside the theory and see the world as it is, i.e. compare our theories about the world with reality, the independent world. Only a fixed, rigid Archimedean platform can supply a base from which to measure the distance between current belief and true belief. However, we cannot connect our world of experience to the independent world, because the Archimedean platform outside of history, outside of time and space, is gone beyond recall. Hence, we have no neutral place to stand to evaluate whether or not our statements and propositions correspond to facts that obtain in the independent world.

Critics argued: Kuhn thinks that in order to be in a position to compare theories from older and more recent periods of normal science one needs a perspective external to each and indeed any era of science, but we never are able to escape from our current perspective.

Hilary Putnam argues that human beings are not in a position to judge whether or not our statements correspond to the independent world. To single out a correspondence between two domains, one needs some independent access to both domains. Kuhn talks as if each theory does refer-namely, to its own “world” of entities.

In 1988, in Dubbing and Redubbing Kuhn explained that, a historian reading an out-of-date scientific text characteristically encounters passages that make no sense. Kuhn had this experience with Aristotle. It has been standard to ignore such passages or to dismiss them as the products of error, ignorance, or superstition, and that response is occasionally appropriate. Kuhn claims that the troublesome passages result in a different diagnosis. The apparent textual anomalies are artifacts, products of misunderstanding.

The historian has been understanding words and phrases in the text as he or she would if they had occurred in contemporary discourse. Through much of the text that way of reading proceeds without difficulty; most terms in the historian’s vocabulary are still used as they were by the author of the text. But some sets of interrelated terms are not, and it is failure to isolate those terms and to discover how they were used that has permitted the passages in question to seem anomalous. Apparent anomaly is thus ordinary evidence of the need for local adjustment of the lexicon, and it often provides clues to the nature of the adjustment as well.

In his 1962 Structure Kuhn considered a pair of successive theories in the same historical line, Incommensurability meant that there was no common language into which both could be fully translated. Some statements constitutive of the older theory could not be stated in any language adequate to express its successor and vice versa. Incommensurability thus equals untranslatability, but what incommensurability bars is not quite the activity of professional translators. Kuhn adopts translation of that sort of Quine, Quine’s arguments for indeterminacy of translation: language is not universal. One must give up the assumption that anything expressible in one language, or by using one lexicon, can be expressed also in any other. Meaning must be abandoned. Anything that can be said in one language can, with sufficient imagination and effort, be understood by a speaker of another. What is prerequisite to such understanding, however, is not translation but language learning. Quine’s radical translator is, in fact, a language learner. Kuhn is suggesting that the problems of translating a scientific text, whether into a foreign tongue or into a later version of the language in which it was written, are far more like those of translating literature than has generally been supposed. In both cases the translator repeatedly encounters sentences that can be rendered in several alternative ways, none of which captures them completely. The content of alternative theories is unable to be compared due to meaning variance of the terms employed by the theories. This leads to the reference problem: Different theories seem to employ the same terms to refer to different things. If reference remains stable through variation of conceptual content, no problem of theory comparison arises, since reference is preserved even though terms may be associated with divergent conceptual content in the context of alternative theories.

Such a refined version of incommensurability was a target for attack. If it is impossible to compare theories either with respect to content or by means of common standards, then it is unclear how a decision between such theories may be made on an objective, rational basis. Such discontinuity in the transition between successive theories (discontinuity in reference), so that no term of a later theory refers to any entity referred to by any earlier theory, conflicts with scientific realism. The realist holds that successive theories in the same domain typically provide alternative descriptions of the same entities and that progress in science consists in an increase in truths known about a common set of entities. But if later theories refer to none of the same entities as earlier theories, then the realist account of scientific progress as increase of truth about a common set of entities is untenable. The realist holds that the entities to which the terms of a theory refer exist independently of the theory, and that the world investigated by natural science is an objective reality which exists independently of human thought. But such assumption may not be shared by those anti-realist philosophers for whom the objects of reference and the world investigated by science depend in some way on human thought. Some anti-realist philosophers hold that the world and the objects it contains are constituted, either in whole or in part, by our theories, concepts or language. Such philosophers may deny that the terms of conceptually variant theories refer to the same objects, since such theories constitute their own domains of reference. Hence, the question of whether later theories refer to the same entities as earlier theories raises metaphysical questions of a kind that tend to divide realism from anti-realism in the philosophy of science.

Critics have attacked Kuhn’s notion of semantic incommensurability. If we do take theories to be potential descriptions of the world, involving reference to worldly entities, kind, and properties, then the problems raised by incommensurability largely evaporate. Critics noted that causal theories of reference permit continuity of reference even through fairly radical theoretical change. Of course, the referentialist response shows only that reference can be retained. Consequently, it is only a partial defense of realism against semantic incommensurability. A further component of the defense of realism against incommensurability must be an epistemic one. For referentialism shows that a term can retain reference and hence that the relevant theories may be such that the later constitutes a better approximation to the truth than the earlier. Nonetheless it may not be possible for philosophers or others to know that there has been such progress.

Putnam

Hilary Putnam

Hilary Putnam’s criticism against Kuhn’s semantic incommensurability is embodied in the following notable fable from 1975. Putnam imagines our world has a Doppelgänger twin Earth, a planet just like our own. Let us suppose that somewhere in the galaxy there is a planet which we can call Twin Earth. Twin Earth is very much like Earth. People on Twin Earth speak English. People on Twin Earth who speak English, i.e. the ones who call themselves “Americans”, “Canadians”, “Englishmen” etc. There are a few differences regarding the standard English language on the earth. These differences themselves depend on some of the peculiarities of Twin Earth. One of the differences on Twin Earth compared to the conditions on Earth is that the liquid called “water” is not H2O but a different liquid with a very long and complicated chemical formula abbreviated xyz, indistinguishable from Water H2O at normal temperature and pressure. When Twin Earthians are thirsty they drink xyz. Water xyz tastes like water and it quenches thirst in the same way as Water H2O. The oceans and lakes, rivers and seas of Twin Earth contain water xyz and rain is consisted of the same liquid. The first contact of the Earthians with Twin Earth will produce a report: The word “water” has the same meaning on Earth and on Twin Earth. After the discovery that the liquid called “water” on Twin Earth is not H2O but xyz, the Earthians would correct their description: “On Twin Earth the word ‘water’ means xyz”. Hence the word “water” has two different meanings: on Twin Earth, what we call “water” (consisting of H2O molecules) simply isn’t water.

Let us return to the time when chemistry was not developed on Earth and on Twin Earth. Somewhere about the year 1750. The average Earthian (Oscar) did not know that water consisted of hydrogen and oxygen. The Twin Earthian (Twin-Oscar) did not know that “water” consisted of xyz. Hence, they would conclude that water and “water were the same and in 1750 no one on either Earth or Twin Earth could have distinguished water from “water”. Therefore, if Oscar and Twin-Oscar are not chemically or metallurgically educated, then there may be no difference at all in their psychological state when they use the word water and “water”.

Let us suppose we have a Doppelgänger on Twin Earth who is molecule for molecule identical with me. My Doppelgänger thinks the same verbalized thoughts as I do. In addition, he has the same sense data, the same dispositions, etc. Therefore, me and my Doppelgänger are in the same psychological state: It is absurd to claim that my Doppelgänger’s psychological state is one bit different from mine. My Doppelgänger cannot tell an elm from a beech tree. He means ‘beech’ when he says ‘elm’, and I on Earth mean elm when I say elm. Putnam concludes: “Cut the pie any way you like, “meanings” [that determine the extension of a term] just ain’t in the head! Hence, the psychological state of my Doppelgänger on Twin Earth and of myself on Earth cannot determine the extension (the group of things the term refers to) of any term.

According to Putnam, if we take into account only the individual psychological or cognitive state of Oscar and Twin-Oscar then water refers to “water” for Twin-Oscar. We do not have to rearrange in different ways the term water for Twin-Oscar. From a cognitive point of view, water is being understood by Oscar and Twin-Oscar as the same thing. Kuhn disagreed with Putnam.

Kuhn replied to Putnam: the report the visitors from Earth send home should not be about language but about chemistry. It must take some form like: “back to the drawing board! Something is badly wrong with chemical theory, and that theory is incompatible with existence of a substance with properties very nearly the same as water but described by an elaborate chemical formula. Such substance would be too heavy to evaporate at normal terrestrial temperatures. Its discovery and presence would demonstrate the fundamental errors in the chemical theory that gives meanings to compound names like H2O”.

In articles written between the late 1980s and early 1990s, Kuhn offered a new account of incommensurability, which localized meaning change to a restricted class of kind terms. These kind terms, together with their interconnections, form taxonomy that classifies the entities studied in a particular scientific field (taxonomic incommensurability). During a taxonomic change, some kind terms from the old taxonomy are preserved. But at the same time some new kind terms are added, some old ones are deleted, and many others are rearranged in different ways. Meaning change happens only in a very restricted class of terms and there always exist unchanged concepts that may be used as basis for rational comparison between rival paradigms. Through the localization of incommensurability, Kuhn hoped to deflect the charge of relativism. In 1993, Ian Hacking related this taxonomy to the world-change thesis: after a revolution the world of individuals remains as it was, but scientists now work in a world of new kinds.

In 1983 and 1991, Kuhn redrew the picture of scientific revolutions. Changes in taxonomy capture the revolutionary features of paradigm shifts, and the most important changes during scientific revolutions can now be conceptualized as taxonomic shifts. The role of taxonomy is not simply linguistic, but also cognitive and psychological. From a cognitive point of view, a taxonomy is a specific structure in the conceptual field defined by a frame. Kuhn sought to distinguish between translating a language (water into “water) and understanding it. Kuhn reasoned that while one might fail to translate from a foreign language into one’s own, it need not follow that one must fail to understand the other language. The combination of these two points yields a refined version of semantic incommensurability, on which translation failure is restricted to specialized vocabularies with a language, which are capable of being understood by rival theories.

Putnam thought that in particular, the individual psychological state of a person does not fix the extension or reference of a term; it is only the sociolinguistic state of the collective linguistic group to which the individual belongs that fixes the extension. Every linguistic community possesses at least some terms that are known only to a subset of the speakers who acquire the terms, and whose use by the other speakers depends upon a structured cooperation between them and the speakers in the relevant subsets.

Sorry no reference list is added here in the blog (to prevent student copying)

 

Men Explain Einstein to Me

If you are a woman, a man has probably at some point explained to you something about the area of your expertise. Rebecca Solnit tells about her own experience with a man who tried to explain (mansplain) a book she wrote to her.

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Mansplainers usually assume you know less than you do because of your gender. Advices.

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Stories.

On March 14 the official Albert Einstein Facebook wall hosted Dr. Debbie Berebiches. This was a Facebook Live Event celebrating Einstein’s birthday. Dr. Berebiches answered questions about Einstein (I haven’t listened to her, I am sorry). Dr. Berebiches is the first Mexican woman to graduate with a Ph.D in physics from Stanford University. Yesterday an Israeli hi-tech veteran explained to her what was “the main contribution of general relativity to GPS”, a topic she clearly knows more about than him. She gave him a like and this was absolutely the right thing to do.

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He then explained things to me, about Einstein’s religion. I am terribly sorry. I may not be the number one expert in Einstein’s philosophy of religion and personal views… well not that he is a great expert in this topic. Subsequently he asked me: “Have you read anything Einstein wrote in German? How about the dice quote? How about general relativity? …” and gave me advices:

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In fact I read many papers and manuscripts in German and when I wake up in the middle of a dream at night, I think I was speaking German to Albert Einstein in my dream.

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I could have stumped him but I preferred not to do this and not to discuss these matters further with him. I don’t believe mansplainers will ever change. Hence, it is better not to stump them and simply ignore them and avoid arguing with them on the area of your expertise. A mansplainer’s advice is unsolicited so you are under no obligation to listen. Advice.

Einstein expressed his religious views in 1922:

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and he also expressed his views in 1930:

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This article is from the Einstein Encyclopedia:

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