1919

Nobel Prize in Physics

Sound Physics From an Unsound Man

Johannes Stark

Johannes Stark made two genuine contributions to atomic physics: he demonstrated the Doppler shift in fast-moving canal rays, confirming that the effect applies to light from moving matter in the laboratory, and he discovered that a strong electric field splits the spectral lines of atoms into multiple components — the Stark effect, a key early window onto the quantum structure of the atom. The discoveries were real, the prize in 1919 was defensible, and the subsequent career was a ruin. Stark became an ardent National Socialist, a loud denouncer of Einstein's "Jewish physics," and a bureaucratic tormentor of colleagues who had the misfortune to need his approval. He ended up tried and convicted by a denazification court after the war. It is possible to hold both things at once: the science was sound, and the man was not. Physics, unlike its practitioners, does not remember the biography.

Nobel Prize in Physiology or Medicine

Naming the Parts of the Immune System

Jules Bordet

When Jules Bordet arrived at the Pasteur Institute in Brussels in the 1890s, immunology was largely a catalogue of observations without a mechanism: bacteria died when blood serum was added to them, and nobody was entirely sure why. Bordet isolated the why — a heat-sensitive system of proteins he called alexin, later renamed complement, which circulates in serum and joins antibodies in punching holes through bacterial membranes. He went further and showed that complement could be quantitatively "fixed" by any antigen-antibody pair, which gave rise to the complement-fixation test; applied to syphilis, this became the Wassermann test, one of the first reliable diagnostic blood tests for a specific disease. A biochemical logic thus replaced what had been a black box, and immunology acquired the skeleton of a proper science. Every subsequent advance in serology — blood typing, allergy research, the understanding of autoimmune disease — owes something to Bordet's insistence that the immune system has parts that can be named and measured.

Nobel Prize in Literature

Gods Rewritten as Vehicles for Doubt

Carl Spitteler

Carl Spitteler was a Swiss poet who spent the better part of his adult life composing an enormous philosophical epic in verse, "Olympian Spring," which retold the Greek Olympians not as mythological furniture but as vehicles for a pessimistic, post-Schopenhauer meditation on fate, freedom, and the indifference of the cosmos. He completed the original version in the 1880s, then rewrote it substantially over the following decades — the kind of sustained, solitary ambition that tends to generate masterpieces or curiosities, and Spitteler's work is perhaps both at once. The Swedish Academy awarded him the prize with a citation praising the "special appreciation" the epic deserved, a formulation that is careful to distinguish admiration from enthusiasm. He is not widely read today, which is not entirely his fault; German-language philosophical poetry of the nineteenth century is a demanding form, and Spitteler demanded it fully. His 1914 lecture urging Swiss neutrality — given while German-language opinion was largely pro-German — showed that the same independence of mind could, when occasion called for it, be rather more useful than a long epic.

Nobel Peace Prize

An Architect Locked Out of His Building

Woodrow Wilson

Woodrow Wilson arrived in Paris in January 1919 to considerable public rapture — crowds in the streets, a level of personal acclaim that surprised even him — and spent six months negotiating the peace settlement that was supposed to end not just a war but the entire system of secret alliances and unchecked sovereignty that had produced it. His Fourteen Points had circulated Europe as something close to a manifesto for a new international order, and the League of Nations, which would give collective security a permanent address, was his most cherished instrument. The Nobel Committee awarded him the 1919 Peace Prize. Then the Senate voted. The United States, whose president had designed the League and whose power would have anchored it, declined to join; the required two-thirds majority was never reached, and Wilson's subsequent national tour to build public pressure ended with a stroke that left him an invalid in the White House. The League persisted for two decades, toothless where it mattered, and wound down in the shadow of the next war. Wilson's legacy is an institution the world eventually had to rebuild from scratch — the United Nations — because the first draft went to press without the author's country inside it.

Eddington's eclipse expedition confirms general relativity

Starlight Bent Exactly as Predicted

On 29 May 1919, the Moon slid across the face of the Sun, and Arthur Eddington stood on the island of Príncipe off the West African coast, anxious about cloud cover, waiting to photograph stars that were only visible because the Sun had been temporarily switched off. A second team set up at Sobral in northern Brazil. The idea was to measure the positions of stars near the solar limb and compare them against their known positions when the Sun was elsewhere in the sky; Einstein's general theory of relativity predicted that the Sun's gravity would bend passing light by 1.75 arcseconds, exactly double the Newtonian expectation. When the plates were measured, the displacement was there, and it matched Einstein's number. The announcement came on 6 November at a joint meeting of the Royal Society and Royal Astronomical Society, beneath a portrait of Isaac Newton, which was either a coincidence or a fine piece of institutional theatre. The Times ran the headline "Revolution in Science — New Theory of the Universe." A continent four years out of the trenches found, briefly, that it preferred physics to politics, and that a German theorist validated by a British expedition was exactly the kind of story it wanted to read.

Rutherford confirms the proton

A Nucleus Finally Gives Up a Piece

Ernest Rutherford had already, in 1911, established that an atom's positive charge and most of its mass live in a tiny central nucleus; what he had not yet done was pull the nucleus apart and identify its components. In experiments published around 1919, he bombarded nitrogen gas with alpha particles and observed that some collisions ejected fast-moving particles with the characteristic properties — charge, mass, ionisation behaviour — of the nucleus of the hydrogen atom. He proposed calling this particle the proton, from the Greek for "first," which was a sensible choice given that the hydrogen nucleus is the simplest case. The proton had been inside every nucleus all along, but it took a collision violent enough to knock one free before anyone could hand it a name. Rutherford also suggested, in the same period, that there must be a neutral particle of similar mass buried in there too — a hunch that took another thirteen years and James Chadwick to confirm. Without the proton's identification, there is no coherent nuclear physics, no periodic table with an underlying explanation, and no route toward the nuclear forces that make stars burn.

Hale's law: sunspot magnetic polarity reverses on an 11-year cycle

A Star That Keeps a Diary

George Ellery Hale was an astronomer of unusual ambition — he founded three successive world-leading observatories and spent his career building ever larger telescopes — and his 1919 work on solar magnetism was characteristic: patient, precise, and consequential. He and his colleagues at Mount Wilson showed that sunspots are regions of intense magnetic field, and that the leading sunspot in an active pair in the northern hemisphere has the opposite polarity to the leading sunspot of a pair in the south; moreover, this polarity arrangement flips at the end of every eleven-year sunspot cycle, so that the complete magnetic cycle of the Sun is twenty-two years, a period now called the Hale cycle. The regularity of it is slightly astonishing — a star ninety-three million miles away running to a schedule you can write in a diary. The practical stakes are not small: solar activity drives geomagnetic storms, disrupts satellites and power grids, and the Hale cycle underlies forecasting efforts for all of it. Hale himself suffered recurring nervous breakdowns, possibly from overwork, and heard imaginary voices offering advice on telescope design. The voices, it must be said, had reasonable taste.

Langmuir introduces the term covalence

Atoms That Share Instead of Steal

Gilbert Lewis had laid the groundwork in 1916, proposing that chemical bonds could be formed by two atoms sharing a pair of electrons rather than by one atom donating electrons entirely to another. It was a profound idea, and it sat in the literature somewhat underappreciated until Irving Langmuir, a General Electric chemist with a talent for synthesis and publicity, took it up in 1919 and refined it into a systematic theory. Langmuir coined the term "covalence" for the shared-pair bond and extended Lewis's octet rule into a broader framework for understanding molecular structure across the periodic table. The picture that emerged — atoms held together not by electrostatic theft but by the democratic sharing of electrons — turned out to describe the vast majority of chemical bonds in organic molecules, the molecules of life among them. Without covalent bonding as a concept, organic chemistry has no explanatory spine: you can catalogue what reacts with what, but you cannot say why. Langmuir went on to win the Nobel in Chemistry in 1932, for other surface chemistry work; Lewis, who had done the foundational thinking, never did, a snub that rankled at the time and is still occasionally raised in the history of science as evidence that the committee is run by humans.

International Astronomical Union founded

One Sky, Agreed Upon at Last

The First World War had done considerable damage to international scientific cooperation, and when it ended, the reconstruction was deliberate and institutional. In July 1919, astronomers from the Allied nations gathered in Brussels as part of the newly formed International Research Council and established the International Astronomical Union — a body whose stated purpose was to coordinate research, standardise nomenclature, and ensure that the world's observatories could compare measurements without the confusion of incompatible conventions. Germany and its wartime allies were initially excluded, a political blemish the IAU took several years to correct. The organisation has operated continuously since, setting the definitions and standards that keep global astronomy coherent: the length of a second, the coordinates of celestial objects, and, most visibly to the general public, the classification of planets. It was the IAU's 2006 General Assembly in Prague that voted Pluto out of planetary status and into the new category of dwarf planet, a decision that generated more popular outrage than almost anything else in modern astronomy — which, given the alternatives, suggests the IAU is doing its job reasonably well.