Satyendra Nath Bose Wrote to Einstein on 4 June 1924, Einstein Translated His Paper and Submitted It by 2 July, and Bosons Carry His Name Though He Never Won a Nobel Prize

On 4 June 1924, Satyendra Nath Bose, a 30-year-old reader in physics at Dacca University (now the University of Dhaka), wrote to Albert Einstein in Berlin and enclosed a short paper that derived Planck’s radiation law without classical electrodynamics. Einstein translated the paper into German himself and by 2 July 1924 had given it to the Zeitschrift für Physik, the journal Bose had asked for. The particles that follow the statistics the paper introduced are called bosons, after him.

Bose never won a Nobel Prize. The Nobel archive lists him as a nominee 11 times, and several points of his story are disputed among the historians who have read the letters. Each is marked below.

A reader without a doctorate writes to Berlin

Bose was born in Calcutta on 1 January 1894. According to the physicist Kameshwar Wali, he took first place in both the BSc (1913) and the MSc (1915) examinations at Presidency College, with his friend Meghnad Saha second. With Saha he translated Einstein’s and Hermann Minkowski’s relativity papers into English, a book the University of Calcutta published in 1920. He moved to the newly founded Dacca University as a reader in 1921, and he held no doctorate.

His covering letter, as Wali reproduces it, said he had tried to deduce the coefficient 8πν²/c³ in Planck’s law independently of classical electrodynamics, assuming only that the smallest regions of phase space (the space of positions and momenta) have the content h³. He wrote that he did not know enough German to translate it. “Though a complete stranger to you, I do not feel any hesitation in making such a request,” he went on. A longer version of the letter in the Indian National Science Academy’s biographical memoir, written by SD Chatterjee in 1983, adds that Bose reminded Einstein of the Calcutta translations and that he had translated the paper on general relativity.

Teaching set the problem, both Wali and Chatterjee say. Saha visited Dacca around March 1924 to examine MSc practicals and told Bose about attempts by Pauli and by Einstein and Ehrenfest to derive Planck’s law. Chatterjee writes that Bose had met the difficulty with his postgraduate students. Wali says Saha’s visit set him thinking about radiation and matter and led to a second paper, sent to Einstein at around the same time as the first. Its covering letter is dated 15 June 1924, Chatterjee notes.

What the paper changed in Planck’s law

Planck’s law of 1900 says how much radiation of each frequency fills a box held at a given temperature. It has two parts: the average energy of each mode of vibration, and the number of modes. Enric Pérez and Tilman Sauer of the Einstein Papers Project note that earlier derivations obtained the average energy from quantisation but had derived the prefactor, the count of modes, only from classical theory.

Bose’s counting was new. In the version Masud Mansuripur reproduces, the phase space of a light quantum is cut into cells of volume h³, each frequency range holds a number of cells that includes two polarisation states, and the quanta are then distributed among the cells. Since the quanta are treated as identical, swapping two of them does not make a new arrangement. Following Abraham Pais, Wali says the derivation made no reference to classical theory and ranks it as the fourth and last of the revolutionary papers of the old quantum theory, after those of Planck, Einstein and Bohr.

Historians differ on how deliberate the counting was. Max Delbrück, writing in 1980, guessed that Bose simply made a mistake in statistics without realising how unusual his way of counting was. Bose later told the historian Jagdish Mehra, as Chatterjee quotes him, that he had no idea what he had done was really novel and had not thought his method differed from Boltzmann’s statistics.

The Philosophical Magazine: rejected, or never answered

Bose had published in the Philosophical Magazine before, with Saha in 1918, and the memoir says he sent this paper there first. The accounts of what happened next differ.

In Wali’s account Bose sent the paper late in 1923 or early in 1924 and, six months later, the editors told him the referee’s report was negative. Chatterjee’s memoir says no acceptance letter arrived for a long time. For Robert Crease and Gino Elia in Physics World, Bose never heard back, though a caption in the same article calls the paper rejected. Pérez and Sauer, citing William Blanpied (1972) and Wali (2006), say the editors had rejected it. Wali adds that the historian John Stachel gives a conflicting account of when the paper was completed. The firm part is that the Philosophical Magazine did not publish it.

Einstein’s postcard and three papers on gases

A postcard from Einstein, dated 2 July 1924, brought the answer. Wali quotes it: “It signifies an important step forward and pleases me very much.” The Springer record shows the Zeitschrift für Physik received the translation on 2 July 1924, and the paper appears in volume 26, pages 178 to 181. In his translator’s note Einstein called the derivation an important advance and said the method also gave the quantum theory of an ideal gas. The sources give different publication months: Chatterjee and the Oxford Dictionary of National Biography say August 1924, while Springer’s record gives December 1924 for the bound issue.

On 10 July 1924 Einstein presented a paper on the quantum theory of the monatomic ideal gas to the Prussian Academy of Sciences. Two days later he wrote to Paul Ehrenfest, in a letter Pérez and Sauer quote in German, that the Indian Bose had given an elegant derivation whose essence stayed obscure, and that he had applied it to an ideal gas. A second paper was read to the Academy on 8 January 1925 and a third on 29 January 1925.

The second paper predicts the Bose-Einstein condensate. Below a critical temperature, Einstein found, a growing share of the molecules would pile into the state of zero momentum. On 29 November 1924 he told Ehrenfest the molecules would “condense” without any attractive forces, calling the theory beautiful and saying he did not know whether it held any truth. That paper also took up a criticism from Ehrenfest and others, that Bose’s counting and Einstein’s own treated the quanta or molecules as not statistically independent. “This is entirely correct,” Einstein wrote, in Pérez and Sauer’s translation.

The Nobel Foundation’s press release for the 2001 physics prize picks up the story. Eric Cornell and Carl Wieman made a pure condensate of about 2,000 rubidium atoms at 20 nanokelvin in 1995, seventy years after the prediction, and the prize went to Cornell, Wolfgang Ketterle and Wieman “for the achievement of Bose-Einstein condensation in dilute gases of alkali atoms, and for early fundamental studies of the properties of the condensates”.

Two years in Paris and Berlin

Wali and Chatterjee both say Einstein’s postcard helped Bose win two years of study leave. He sailed from Bombay in early September 1924 and reached Paris in mid-October, lodging at the Indian Students’ Association building on the Rue du Sommerard. Marie Curie, Bose recalled, told him to wait three or four months and learn French before working in her laboratory, so he joined Maurice de Broglie’s X-ray laboratory instead. Paul Langevin was another contact there.

On 26 October Bose wrote to Einstein from Paris asking to work under him. Einstein answered on 3 November that he would be glad to meet, and that he did not agree with the probability law in Bose’s second paper, the one on thermal equilibrium of radiation in the presence of matter, which Einstein had also translated and annotated. A third paper, announced by Bose on 27 January 1925, was never published, and Wali reports no trace of it in the Einstein Archives at the Hebrew University of Jerusalem.

Berlin came in October 1925, according to Wali and the Oxford biography. There Einstein introduced him to Fritz Haber, Otto Hahn, Lise Meitner and Walter Gordon, and set him two problems, on the statistics of light quanta. Bose made no progress on either, Wali writes. Chatterjee adds a visit to Göttingen in the summer of 1926, where he met Max Born, before his return to Dacca that year.

A later recollection comes from the physicist Partha Ghose, a former student of Bose. In an April 2005 talk at Dhaka University, Ghose said Bose once told him, in confidence, that his derivation had first given 4πν²/c³ instead of 8πν²/c³, and that he had proposed the missing factor of 2 came from the photon having a spin of one unit. Ghose recalls Bose saying in Bengali, with a sad smile, “The old man crossed it out!” Wali adds that Einstein apparently put the two polarisation states in its place. This rests on Ghose’s memory of a private conversation, and Wali presents it that way.

Dacca, Calcutta and the honours

With no doctorate, Bose was advised by friends to get a recommendation from Einstein before applying for the Dacca chair. Einstein wrote that Bose’s recent work, especially on radiation equilibrium, signified “an important and enduring progress of the physical theory”. Chatterjee says the chair was first offered to DM Bose, who declined, and that SN Bose became Professor of Physics and head of department in 1927.

At Dacca he built X-ray diffraction cameras and a crystallography programme, and took up organic chemistry. In 1945 he left for the University of Calcutta as Khaira Professor. The memoir gives the reason as communal tension in Dacca, which disturbed him. Wali writes that Bose’s research achievements were less sustained and less numerous than those of contemporaries such as Saha and CV Raman.

Bose sat in the Rajya Sabha from 1952 to 1958, and the government’s science portal gives 1954 as the year of his Padma Vibhushan. In 1958 the Royal Society elected him a Fellow. After retiring from Calcutta in 1956 he became vice-chancellor of Visva-Bharati, the university at Santiniketan that Rabindranath Tagore founded, until 1958, and then served as National Professor. In the mid-1950s he published five papers on Einstein’s unified field theory. When news of Einstein’s death came, Chatterjee writes, Bose tore up the only copy of an important paper of his own.

Where the word boson came from

The term comes from Paul Dirac. Gordon Fraser and Michael Riordan write in Physics World that in a public lecture in “war-ravaged Paris” in December 1945 he called Fermi’s particles fermions and Bose’s particles bosons, and the names stuck. MacTutor credits him with the coinage as well. Pauli supplied the link between the two classes and spin in 1936 and 1940, Chatterjee says: particles with whole-number spin follow Bose statistics and those with half-number spin follow Fermi statistics.

Physics World defines a boson as any particle with a whole-number quantum spin, and CERN says the Higgs boson is the only particle with a spin of zero. ATLAS and CMS announced the discovery on 4 July 2012, and the Nature Physics editorial of 2024 calls “boson” probably one of the most widely recognised physics terms since then. India’s part in that search is covered in our article on India at CERN.

Eleven nominations and no prize

The Nobel archive lists Bose as the nominee in 11 nominations: 1956, 1959, two in 1962, one each in 1968, 1969 and 1970, three in 1971 and one in 1972. Five of them, from 1968 to 1972, came from MGK Menon. The archive records nominator and nominee, and none of the sources used here reports a committee reason for passing him over.

One rule and two prizes frame the record. The Nobel Foundation’s statutes say that work produced by a person since deceased “shall not be considered for an award”. Bose died on 4 February 1974, so no prize for his own work was possible after that date. The first condensate came in 1995 and the prize for it in 2001. The 2013 physics prize went to François Englert and Peter Higgs for the theoretical discovery of a mechanism behind the origin of mass, confirmed by the particle found at CERN. Writing in Physics World in 2023, Hannah Schmalstich observes that Bose won no Nobel for his contribution behind the boson.

Two sources offer an account of temperament, not of the committee’s reasoning. Wali writes that after his early success Bose “fell into the trap of being a perfectionist”, published only ideas he thought worthwhile and never kept notes. Chatterjee says he shunned publicity and had resolved to “espouse obscurity”.

On 10 January 1974, about a month before he died, Bose wrote to his friend Jacqueline Eisenmann, whom he had met in Paris, that the university was sponsoring a conference on statistical physics and had called it the 50th anniversary of Bose statistics.