1921

Nobel Prize in Physics

Light Arrives in Packets, Not Waves

Albert Einstein

By 1921, Albert Einstein had already produced the special theory of relativity, the general theory of relativity, and the field equations that govern the large-scale shape of the universe — and the Nobel Committee, regarding all of this with an uneasy mixture of awe and philosophical suspicion, decided to give him the prize for something else entirely. The photoelectric effect: the discovery, set out in a short 1905 paper, that light does not arrive at a metal surface in smooth waves but in discrete packets, each packet carrying energy proportional to its frequency, and that below a certain threshold frequency no electrons are ejected no matter how bright the lamp. It was this work that first made quantum mechanics unavoidable, smuggling discontinuity into physics through an apparently modest door. The committee found relativity too speculative; the photoelectric effect was, to their minds, empirically solid — which is one way of saying that they awarded the most famous physicist alive a prize for his most underrated contribution. Without it, there is no photoelectric cell, no solar panel, and no reliable explanation of why the universe contains chemistry at all.

Nobel Prize in Chemistry

Same Place on the Table, Different Weight

Frederick Soddy

The puzzle that Frederick Soddy resolved was one that had quietly embarrassed chemists for decades: why did careful measurements of atomic weights keep coming out as fractional averages rather than clean whole numbers? Working alongside Ernest Rutherford in the early 1900s on the transmutation of radioactive elements, Soddy arrived at the unsettling conclusion that a single element could exist in multiple forms, identical in chemical behaviour but different in atomic mass — occupying, as he put it in 1913, the same place on the periodic table. He coined the word isotope from the Greek for exactly that: same place. The concept explained, at a stroke, why uranium ore produced a bewildering variety of lead, why the apparent atomic weights of elements seemed to resist whole numbers, and why radioactive decay chains had so many more members than anyone expected. It also, in retrospect, quietly set up everything that followed in nuclear physics, from fission reactors to carbon dating. The prize came to him in 1922, nominally for 1921 — a typical instance of the Nobel calendar's constitutional reluctance to be hurried.

Nobel Prize in Literature

Irony Polished Until It Looked Like Peace

Anatole France

Jacques Anatole Thibault — who wrote as Anatole France and lived as the very embodiment of cultivated Parisian scepticism — had spent half a century producing novels, essays, and tales distinguished by an irony so polished it could be mistaken for serenity. The Swedish Academy, awarding him the prize in 1921, praised his noble style, his profound human sympathy, his grace, and what they called a true Gallic temperament: a formulation that manages simultaneously to honour a man and flatten him into a national type. France accepted the prize with the air of someone who had long since made peace with the world's absurdities, which is perhaps the only appropriate response to being celebrated for your wit by a committee speaking in solemn paragraphs. His reputation dimmed considerably after his death — André Breton and the Surrealists loathed him with the particular venom reserved for the recently canonical — but his best work, the quiet, cruel precision of his satire, retains the quality that made it dangerous: it never shouts.

Nobel Peace Prize

The Chamber and the Archive, Together

Karl Hjalmar Branting · Christian Lous Lange

The 1921 Peace Prize was divided between two men whose internationalism expressed itself through entirely different temperaments. Karl Hjalmar Branting had spent his career as a Swedish Social Democratic politician navigating the slow, argumentative machinery of parliamentary democracy toward international arbitration and the League of Nations — a kind of principled optimism that required, above all, the patience to remain optimistic while watching things move very slowly. Christian Lous Lange, by contrast, had served for years as secretary-general of the Inter-Parliamentary Union, an organisation devoted to encouraging communication among parliaments that had not, on the whole, been notably communicative, and had written extensively on the history and theory of internationalism as an idea. Where Branting practised peace as politics, Lange practised it as scholarship. The committee's decision to split the prize between them reads less like a compromise and more like an acknowledgement that durable internationalism requires both: the man in the chamber and the man in the archive.

Isolation of insulin at the University of Toronto

An Afternoon in a Basement Changed Diabetes

Before the summer of 1921, a diagnosis of type 1 diabetes was, for a child, a slow death sentence measurable in months. The standard treatment was a near-starvation diet that extended life slightly while making it considerably less worth living. Frederick Banting, a young Ontario surgeon with no research background and a borrowed laboratory, had the idea of tying off dogs' pancreatic ducts to let the digestive tissue atrophy while preserving the islets of Langerhans — the clusters of cells long suspected of producing whatever hormone controlled blood sugar. He and medical student Charles Best extracted the resulting secretion, injected it into a diabetic dog, and watched the animal's blood sugar fall. James Collip then spent weeks purifying the extract until it could be given to a human without causing severe reaction. On 11 January 1922, a fourteen-year-old boy named Leonard Thompson, near death in a Toronto ward, received the first successful human injection; within hours his blood sugar was falling. The Nobel Prize followed in 1923, but the year that mattered was 1921, when an afternoon in a basement laboratory changed what diabetes meant.

Kaluza proposes five-dimensional unification of gravity and electromagnetism

A Fifth Dimension, Curled Tightly Enough to Hide

In April 1919, the Polish mathematician Theodor Kaluza sent Einstein a letter proposing something extraordinary: that if you extend general relativity to five dimensions rather than four, and then look at what falls out when you set that fifth dimension aside, you recover Maxwell's equations for electromagnetism as a natural consequence. It was, in other words, a potential explanation for why gravity and electromagnetism both exist — they are, perhaps, the same thing viewed from different angles in a richer space. Einstein received the paper, found it remarkable, sat on it for two years, and finally presented it to the Prussian Academy in 1921, apparently needing time to decide whether genius and madness were operating in the correct proportions. The fifth dimension, Kaluza noted, need not be observable if it is curled tightly enough — a suggestion that Oskar Klein later made precise and that physicists have been borrowing ever since, most recently in string theory's requirement for extra dimensions compact enough to evade all experiment. The theory was ultimately wrong in its details but right in its audacity: the idea that geometry might explain force has never quite gone away.

Emmy Noether publishes ideal theory in rings

The House She Built, Under Someone Else's Name

Emmy Noether had been lecturing at Göttingen for years under someone else's name — listed, as a matter of administrative necessity, under David Hilbert's, since the university's faculty remained constitutionally opposed to a woman holding a proper position — before she published, in 1921, the paper that reorganised abstract algebra around a single powerful idea. The paper established that if a ring satisfies what is now called the ascending chain condition on ideals — roughly, that you cannot have an infinite strictly increasing sequence of sub-structures — then its arithmetic behaves in the orderly way one would hope: things factorise, ideals decompose, the whole enterprise is well-founded. Rings satisfying this condition are now called Noetherian, which is one of mathematics' tidier tributes. The deeper achievement was methodological: Noether showed that the right way to understand algebraic structures was through their abstract properties rather than their explicit elements, an approach so influential that modern algebra is largely built in its image. The field that had spent decades politely ignoring her ended up living in the house she built.

Chadwick and Bieler identify anomalous proton scattering — first evidence of the strong force

Mortar Between the Bricks, Still Unnamed

In 1921, James Chadwick and Étienne Biéler were firing alpha particles at hydrogen nuclei and watching where they went, expecting the angles of deflection to obey the Coulomb law of electrical repulsion, which is to say expecting the nucleus to behave as a simple charged sphere. It did not. Particles were bouncing back at angles far larger than the electrical force alone could produce, and doing so in a way that strongly suggested something additional was operating at very short distances — something powerful, attractive, and entirely unlike electromagnetism. Chadwick and Biéler published their findings with a characteristic restraint, concluding that the forces between charged particles must deviate significantly from the inverse-square law at close range. They had no name for what they had found, which is perhaps appropriate, since giving it a name would have implied understanding it — and another decade would pass before the strong nuclear force was sufficiently theorised to be named at all. They had, in effect, detected the mortar between the bricks of matter without yet knowing what mortar was.

McCollum identifies vitamin D and its role in preventing rickets

Cod Liver Oil Held a Second Secret

By 1921, Elmer McCollum had already done more than most nutritionists do in a career: he had identified vitamins A and B, established the importance of calcium and phosphorus in diet, and introduced the white rat as the standard animal for nutritional research, which is a legacy that has made him somewhat more famous among laboratory suppliers than among the general public. His 1921 work on rickets — the bone-softening disease that had bowed the legs of European city children for centuries — revealed that cod liver oil contained something beyond the vitamin A he had already identified, something that cured rickets in rats even when vitamin A was chemically removed. He called it vitamin D. The subsequent discovery that the same compound could be produced by skin exposed to sunlight explained why rickets flourished in the smoky, sun-deprived industrial cities of the nineteenth century. The eventual decision to fortify milk with vitamin D in the 1930s amounted to a quiet public-health intervention of considerable scale — a generation of children grew up with straight limbs and had no particular reason to know why.

Thomas Midgley discovers tetraethyllead as an anti-knock additive

Silencing an Engine, Poisoning the Air

The knocking in petrol engines — the metallic rattling produced by fuel igniting before the piston is ready — was in 1921 a serious engineering problem, limiting the efficiency and power of the internal combustion engine at a moment when the car industry was expanding at considerable speed. Thomas Midgley Jr., working for General Motors under Charles Kettering, had tried dozens of compounds before tetraethyllead silenced the knock with satisfying completeness. He demonstrated it on 9 December 1921, and within a few years leaded petrol was the global standard. Midgley himself contracted lead poisoning from the work — a warning the industry absorbed without particular urgency. Leaded fuel persisted for fifty years across most of the world, depositing lead into the air, soil, and bloodstream of essentially every person living near a road, with measurable effects on IQ and behaviour that researchers are still quantifying. Midgley, who would later invent chlorofluorocarbons as a safe refrigerant, has the unusual distinction of having done more damage to the atmosphere than any other single organism in history — which is quite an achievement for a man who was trying, in both cases, to be helpful.

First BCG tuberculosis vaccination administered

Two Hundred Thirty Generations to a Safer Strain

Tuberculosis killed more people in the nineteenth century than any other infectious disease, moving silently through tenements and workhouses and the lungs of poets with democratic efficiency. Albert Calmette and Camille Guérin had spent thirteen years at the Pasteur Institute cultivating and re-cultivating a strain of Mycobacterium bovis — the bovine form of the tuberculosis bacterium — through 230 successive generations until it had lost its capacity to cause disease while retaining the ability to provoke an immune response. On 18 July 1921, a newborn in Paris whose mother had died of tuberculosis became the first person to receive the resulting vaccine orally; the infant survived, and the BCG programme spread outward from France in the following decade. The vaccine is imperfect — its efficacy against pulmonary tuberculosis in adults has been a persistent subject of debate — but as a shield for infants and against the severe forms of childhood TB, it has been one of the most widely administered in history, delivered to billions of newborns in the century since that first careful dose.

Death of Henrietta Swan Leavitt

A Ruler for the Universe, Uncounted Herself

Henrietta Swan Leavitt

Henrietta Swan Leavitt died on 12 December 1921, at fifty-three, having spent most of her career at the Harvard College Observatory cataloguing the brightness of stars from photographic plates, a role classified as that of a human computer rather than a scientist. Her 1912 paper on Cepheid variable stars in the Small Magellanic Cloud — stars that brighten and dim with a period precisely correlated to their intrinsic luminosity — gave astronomers what they had never had: a reliable way to measure vast distances. If you know how bright a Cepheid truly is, and you measure how bright it appears, the difference tells you how far away it must be. Edwin Hubble used her period-luminosity relation in 1924 to measure the distance to the Andromeda nebula and established, conclusively, that it lay far outside the Milky Way — that the universe was incomparably larger than anyone had supposed. A Swedish mathematician, Erik Holmberg, later wrote to propose her for a Nobel Prize; he was informed she had died, and the prize cannot be awarded posthumously. The ruler she made measured everything; she herself was not counted.

Birth of Yoichiro Nambu

Symmetry the Universe Chose to Break

Yoichiro Nambu

Yoichiro Nambu was born in Tokyo on 18 January 1921, and would go on to become one of the quieter architects of the Standard Model — a physicist whose contributions were so far ahead of experimental confirmation that the Nobel Committee had to wait until 2008, when Nambu was eighty-seven, before the evidence had caught up sufficiently to justify the prize. His key insight, developed in the early 1960s, was that nature's equations can possess symmetries that the actual solutions to those equations do not share — that the ground state of a system can be less symmetric than the laws governing it, a phenomenon he termed spontaneous symmetry breaking. The concept, seemingly abstract, turned out to be indispensable: it underlies the Higgs mechanism by which particles acquire mass, the theory of superconductivity, and the quark model of the proton. He also introduced the concept of what became string theory, almost as an aside, in 1970. In a field populated by figures of considerable self-advertisement, Nambu worked with a reticence that made him easy to overlook and impossible, in the end, to ignore.