EINSTEIN, Albert.

Interferenzeigenschaften des durch Kanalstrahlen emittierten Lichtes. [Issued with:] & RUPP, Emil. Über die Interferenzeigenschaften des Kanalstrahllichtes. Offprint from: Sitzungsberichte der Preussischen Akademie der Wissenschaften, XXV, XXVI, November 1926.

Berlin: Akademie der Wissenschaften, 1926.

First edition, extremely rare author’s presentation offprint (not to be confused with the much more common trade separate – see below), from the library of the great German physicist Arnold Sommerfeld, of the notorious Einstein/Rupp experiments. “In the fall of 1926, Albert Einstein published the outline of two experiments in the Proceedings of the Berlin Academy. They addressed one of the most urgent questions in physics at the time: the experiments were to show if the emission of light was a process that was extended in time, or if instead light emission occurred in an instantaneous act. Of course, the first possibility would confirm a traditional oscillator-and-wave-like view, whereas the second possibility would cohere well with Einstein’s own ideas on light quanta. It is quite surprising that these experiments are so unfamiliar today. Apart from addressing a central question and being proposed by no lesser figure than Einstein, they also circulated at a crucial moment in the history of quantum theory. Still, the experiments are not mentioned in any of the standard Einstein biographies and there is no substantial treatment of them in histories of the quantum theory … The likely cause for this lack of attention is at least as surprising: the experiments were—supposedly—conducted by Emil Rupp, yet a decade later Rupp was exposed as a scientific fraudster; the results, obtained by Rupp in close consultation with Einstein and published back-to-back with the latter’s theoretical paper, were in the end generally believed to have been fabrications” (Van Dongen). As Walter Gerlach (of Stern-Gerlach fame) said (in an interview with Thomas Kuhn in 1963), “Rupp, in the late twenties, early thirties, was regarded as the most important and most competent physicist. He did incredible things. … Later, it turned out that everything that he had ever published, everything, was forged. This had gone on for ten years, ten years!” Nevertheless, “these experiments played a substantial role in developments in 1926. Most importantly, they confirmed a wave picture of light, when many, including Einstein himself, initially expected a particle-like, instantaneous picture of light emission to be confirmed. After all, only a few years before Compton scattering had been shown, and as little as a year before the Einstein-Rupp experiments Walther Bothe and Hans Geiger had done the experiments that dismissed the BKS theory. But the experiments of Einstein and Rupp also influenced events in other ways. For instance, their initial interpretation was most likely of direct importance for Max Born, when he proposed the probabilistic interpretation of the wave function. The experiments further played a role in the thinking of Werner Heisenberg, as he formulated his uncertainty relations … these experiments deserve renewed attention, and their current obscure status is not warranted by their historical importance” (Van Dongen). OCLC locates only three copies, two in Switzerland, one in Germany, but it is unclear which of these (if any) are author’s presentation offprints. The presentation offprint was not present in the collection of Einstein’s son Hans Albert (Christie’s 2006), but it was in Einstein’s own collection of his offprints (Christie’s 2008).

Provenance: Arnold Sommerfeld (1868-1951) (his characteristic numbering (‘46’) in red pencil on front cover). “The son of a physician, Sommerfeld was educated at the University of Königsberg. After teaching briefly at the universities of Göttingen, Clausthal, and Aachen he was appointed professor of physics at the University of Münich in 1906. Sommerfeld should have retired in 1936 in favour of his pupil, Werner Heisenberg. Opposition from the Nazi party to Heisenberg’s appointment prolonged Sommerfeld’s tenure and it was not in fact until late 1939 that he finally retired, to be succeeded not by Heisenberg but by Wilhelm Müller, a Nazi aerodynamicist without a single publication in physics to his credit. Although Sommerfeld and Heisenberg were not Jewish, they were regarded by the Nazis as Jewish sympathizers. Sommerfeld, however, survived the war and returned to his Münich chair in 1945, continuing to work at physics until he died in a car accident in 1951” (Oxford Reference). “Arnold Sommerfeld was one of the most distinguished representatives of the transition period between classical and modern theoretical physics. The work of his youth was still firmly anchored in the conceptions of the nineteenth century; but when in the first decennium of the century the flood of new discoveries, experimental and theoretical, broke the dams of tradition, he became a leader of the new movement, and in combining the two ways of thinking he exerted a powerful influence on the younger generation. This combination of a classical mind, to whom clarity of conception and mathematical rigour are essential, with the adventurous spirit of a pioneer, are the roots of his scientific success, while his exceptional gift of communicating his ideas by spoken and written word made him a great teacher” (Max Born, p. 275).

“Born in 1898, Rupp began his career in the 1920s studying canal rays, beams of positive ions and atoms formed between an anode and cathode, the latter punctured with holes (or “canals”), in a gas discharge tube. When these rays shoot through the canals and into a vacuum chamber, the ions rapidly lose and gain charge, emitting visible light that becomes less intense at the other end of the canal.

“In his first experiments in the mid-1920s, Rupp measured the coherence length of light — the distance over which the light maintains a consistent phase — emitted by hydrogen and mercury atoms in the canal rays. He measured these lengths as 62 centimeters for hydrogen and 15.2 centimeters for mercury. These were blockbuster results: A moving hydrogen atom was expected to stay coherent over a much smaller distance.

“What’s more, Rupp’s extra-long hydrogen canal ray seemed like it could be used to test one of physics’ biggest questions at the time: Is light a particle or a wave? Einstein had devised experiments to test if light was emitted instantaneously or over time, but he needed a light with an extra-long coherence length — and only Rupp had achieved it.

“After reading Rupp’s 1926 paper, Einstein published his own “Proposal for an Experiment on the Nature of the Elementary Process of Radiation Emission” and reached out to Rupp directly to discuss a collaboration. But because Rupp’s boss at Heidelberg University, the physicist Philipp Lenard, was “a fervent anti-relativist — and anti-Semite,” writes van Dongen, Einstein chose to forgo a visit to the institution and sent instructions for Rupp to do the experiments on his own.

“There were red flags from the start. In one instance, Rupp appeared to have altered the mirrors in his interferometer (the instrument he used to study interference) just so, into an arrangement that would obtain desired outcomes. In another instance, when Einstein corrected the settings Rupp reported using for another instrument, Rupp chalked the mistake up to a typo. There were other ‘alarming discrepancies’ in Rupp’s calculations, van Dongen writes, and Einstein’s letters show that he pushed back on several occasions. Each time, Rupp responded with new results that perfectly explained the oddities Einstein questioned.

“Initially, Einstein expected to find that light was emitted instantaneously. But as the collaboration stretched on, he began to expect the experiments would confirm the alternative, the ‘classical’ theory. ‘One of the reasons for his changing position likely was that that outcome had inadvertently already been corroborated by Rupp,’ van Dongen writes.

“When Rupp furnished Einstein with a final set of results supporting the classical emission picture, Einstein facilitated their publication in the proceedings of the Prussian Academy of Sciences. They were published back-to-back with a paper by Einstein explaining the theory behind the experiments, in which Einstein cited Rupp’s work. Einstein even helped Rupp draft his paper’s abstract.

“The association with Einstein rocketed Rupp to scientific prominence, and in 1928, he accepted a position in the research labs of German electronics company AEG, ‘a kind of counterpart to General Electric,’ writes MIT physicist Anthony French in his 1999 retrospective of Rupp’s case.

“However, scientists had begun voicing skepticism about Rupp’s canal ray work. Among them were British spectroscopist Robert d’Escourt Atkinson, who doubted Rupp’s extraordinary coherence lengths, and a researcher named Harald Straub, who tried and failed to replicate Rupp’s measurements in 1930. Rupp came down hard on Straub with a rebuttal, sending photographs that supposedly showed his interference fields and forcefully defending his work in the same journal where Straub published his. Straub wrote that he had nothing else to add, and the matter appeared settled.

“But Rupp’s reputation was bruised in the episode, and his letters from the time indicate that his funding at AEG was drying up. He published work on electron scattering, then took up experiments with positrons, producing them by pounding lithium with protons. In a 1934 paper, Rupp claimed to have accelerated protons at potential differences of 500 kV. This was impossible for him to have done — he simply did not have the requisite accelerator in his lab.

“In December 1934, two of Rupp’s fellow scientists at AEG brought the glaring problem to the attention of the institute’s director, who launched an investigation and subsequently fired Rupp. In January 1935, Rupp published the retraction statement appended to his doctor’s note, claiming he had no knowledge of or control over the fabrications. And later that year, experimentalists Walther Gerlach and Eduard Rüchardt published ‘On the Coherence Length of Light emitted by Canal Rays,’ which essentially confirmed that Rupp’s early canal ray work was also erroneous. Amid this public humiliation, Rupp experienced a nervous breakdown and spent time in a sanatorium. He never worked in physics again.

“Einstein, however, escaped from the episode unscathed. Historians like van Dongen think his credulousness was an honest mistake, underpinned by his desire to see his theories confirmed by experiments. Rupp’s work and life are now a footnote, but following his downfall, it appears that German scientists mentioned his name often. According to French, ‘for a number of years afterward, the word ‘geruppt’ became an epithet among German physicists to describe questionable work’” (Jooss).

This author’s presentation offprint is of extreme rarity and must be distinguished from other so-called ‘offprints’ of papers from the Berlin Sitzungsberichte, many of which are commonly available on the market. The celebrated bookseller Ernst Weil (1919-1981), in the introduction to his Einstein bibliography, wrote: “I have often been asked about the number of those offprints. It seems to be certain that there were few before 1914. They were given only to the author, and mostly ‘Überreicht vom Verfasser’ (Presented by the Author) is printed on the wrapper. Later on, I have no doubt, many more offprints were made, and also sold as such, especially by the Berlin Academy.” If the term ‘offprint’ means, as we believe it should, a separate printing of a journal article given (only) to the author for distribution to colleagues, then ‘offprints’ were not commercially available. Although there is certainly some truth in Weil’s remark, in our view it requires clarification and explanation.

Until about 1916, most of Einstein’s papers were published in Annalen der Physik; from 1916 until he left Germany for the United States in 1933, most were published in the Berlin Sitzungsberichte. The Sitzungsberichte differed from other journals in which Einstein published in that it made separate printings of its papers commercially available. These separate printings have ‘Sonderabdruck’ printed on the front wrapper, the usual German term for offprint, but they are not offprints according to our definition. They were available to anyone; indeed a price list of these ‘trade offprints’ is printed on the rear wrapper. True author’s presentation offprints can be distinguished from these trade separates by the presence of ‘Überreicht vom Verfasser’ on the front wrapper.

In the period 1916 to 1919 or 1920, the Sitzungsberichte trade separates are themselves rare. After 1919 or 1920, however, the trade separates become much more common, although the author’s presentation offprints are still very rare. The reason for this change is that it was only in 1919 that Einstein became famous among the general public.

It might seem obvious that Einstein’s fame dates from 1905, his ‘annus mirabilis’, in which he published his epoch-making papers on special relativity and the light quantum. However, these works did not make him immediately well known even in the physics community – many physicists did not understand or accept his work, and it was two or three years before his genius was fully accepted even by his colleagues. Einstein did not secure an academic position until 1908. Among the general public, Einstein became well known only in late 1919, following the success of Eddington’s expedition to observe the bending of light by the Sun, which confirmed Einstein’s general theory of relativity. This was front-page news and made Einstein universally famous. (See Chapter 16, ‘The suddenly famous Doctor Einstein’, in Pais, Subtle is the Lord, for an account of these events). Before 1919 the trade separates of Einstein’s papers would probably only have been purchased by professional physicists; after 1919 everyone wanted a memento of the famous Dr. Einstein, whether or not they understood anything of theoretical physics, and the trade separates of his papers were printed and sold in far greater numbers than before to meet the demand. It is telling that when these post-1919 trade separates appear on the market, they are often in mint condition – they were never read simply because their owners were unable to understand them.

BRL 160; Weil 153. Born, ‘Arnold Johannes Wilhelm Sommerfeld 1868-1951,’ Obituary Notices of Fellows of the Royal Society 8 (1952), pp. 275-296. French, ‘The strange case of Emil Rupp,’ Physics in Perspective 1 (1999), pp. 3-21. Joosse, ‘December 1934: Emil Rupp’s research, which fooled even Einstein, is exposed as fraud,’ APS News, Nov. 14, 2023. Van Dongen, ‘Communicating the Heisenberg uncertainty relations: Niels Bohr, complementarity, and the Einstein-Rupp experiments,’ Scientia Danica. Series M, Mathematica et physica, 1: One Hundred Years of the Bohr Atom, Proceedings (2015) pp. 310-343.

8vo (252 x 180 mm), pp. 334-340; 341-351. Original printed wrappers (portion of ink postmark stamp on lower cover just into text of publisher’s advertisements, light vertical crease for posting).

Item #6414

Price: $1,250.00