1904

Nobel Prize in Physics

Lord Rayleigh (John William Strutt)

Rayleigh noticed that nitrogen extracted from the air was slightly heavier than nitrogen produced chemically — a discrepancy of one part in two hundred, small enough to ignore, which he did not. The extra weight turned out to be argon, an element so unreactive it had hidden in air for the entire history of chemistry without anyone noticing it was there.

Nobel Prize in Chemistry

Sir William Ramsay

Ramsay identified not only argon but the rest of the noble gas family: helium, neon, krypton, and xenon, each pulled from air by patient fractional distillation. They filled a conspicuous gap in the periodic table that no one had previously realised was a gap. Inertness, it turned out, was an identity.

Nobel Prize in Physiology or Medicine

Ivan Pavlov

Pavlov was studying digestive secretion in dogs — specifically what made them salivate — when he noticed they began salivating before the food arrived, at the sound of a footstep or a bell. He spent the next three decades mapping the rules of this learned anticipation, which he called conditioned reflexes. The prize was officially for digestion research. The reflex work, which was what the century would remember, came with it for free.

Nobel Prize in Literature

Frédéric Mistral · José Echegaray

The prize was split between Mistral, who had spent his life reviving Provençal as a literary language and writing a twelve-book epic poem in it, and Echegaray, a Spanish engineer who had become a playwright. They shared the award and, presumably, the somewhat awkward knowledge that neither was Chekhov, who was also alive that year.

Nobel Peace Prize

Institute of International Law

The Institute of International Law, founded in 1873, had spent thirty years codifying the legal rules that should govern relations between states and the conduct of war. The committee awarded it the Peace Prize for the proposition that making the laws of war more humane is, if not a solution, at least a beginning.

Discovery completes the noble gas group

With Rayleigh's argon and Ramsay's subsequent identifications, the complete family of noble gases — helium, neon, argon, krypton, xenon — was assembled. Radon would follow shortly. They occupied a previously blank column in the periodic table, which retrospectively made the table look far more incomplete than Mendeleev had realised when he designed it.

Pavlov demonstrates conditioned reflexes

Dogs trained to associate a bell with food would salivate at the bell alone — a simple observation that launched decades of research into learning, behaviour, and the physical basis of memory. Pavlov's careful experimental design, measuring saliva output drop by drop, turned a dining-room observation into a quantitative science.