1919

Nobel Prize in Physics

Johannes Stark

Stark discovered that fast-moving canal rays show a Doppler shift in their spectral lines, and that strong electric fields split atomic spectral lines into components — the latter now called the Stark effect. He later became an enthusiastic Nazi and a vicious opponent of "Jewish physics," which casts a shadow over an otherwise genuine set of discoveries.

Nobel Prize in Physiology or Medicine

Jules Bordet

Bordet discovered complement — a system of proteins in blood serum that assists antibodies in destroying bacteria. He also developed a practical test for syphilis using complement fixation, a technique with broad diagnostic applications. His work gave immunology a biochemical foundation it had previously lacked.

Nobel Prize in Literature

Carl Spitteler

Spitteler was a Swiss poet whose epic "Olympian Spring" retold Greek mythology at enormous length and in a distinctly nineteenth-century philosophical register. He had written it over several decades. The Academy's citation cited its "special appreciation" rather than enthusiasm, which is a distinction worth noting.

Nobel Peace Prize

Woodrow Wilson

Wilson received the prize for proposing and founding the League of Nations. The irony was immediate and complete: his own country, the United States, refused to join the organisation he had created, after the Senate declined to ratify the Treaty of Versailles. The League limped on without America for two decades before disbanding after the next war.

Eddington's eclipse expedition confirms general relativity

On 29 May, Eddington observed a total solar eclipse from the island of Príncipe, while a second team worked from Sobral in Brazil. Stars near the darkened Sun appeared shifted from their true positions by 1.75 arcseconds — exactly the deflection Einstein's equations predicted. The results were announced on 6 November at a joint meeting of the Royal Society and Royal Astronomical Society, beneath a portrait of Newton. The Times ran the headline "Revolution in Science."

Rutherford confirms the proton

Following his earlier transmutation experiments, Rutherford now established clearly that the particle ejected when alpha particles strike light atomic nuclei is identical to the nucleus of the hydrogen atom. He proposed the name proton. The particle had been sitting inside every nucleus all along; it took artificial transmutation to bring one out and name it.

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

George Ellery Hale and his colleagues showed that the leading sunspot in a solar active region has the opposite magnetic polarity to the leading sunspot in the other hemisphere, and that this polarity flips every eleven years. The full magnetic cycle of the Sun therefore takes twenty-two years. The pattern is called Hale's law and holds to this day.

Langmuir introduces the term covalence

Irving Langmuir formally named the sharing of electron pairs between atoms "covalence" and developed Lewis's ideas into a systematic theory of molecular bonding. The electron pair bond — two atoms sharing two electrons — became the standard picture of how molecules hold together.

International Astronomical Union founded

In the aftermath of the war, astronomers from the Allied nations met in Paris to establish the International Astronomical Union, providing a coordinating body for research, nomenclature, and the standardisation of measurements across national observatories. It is still the body that decides, among other things, what counts as a planet.