1917

Nobel Prize in Physics

Every Element Has Its Own Signature

Charles Glover Barkla

When X-rays pass through matter, physicists had long noticed that the material fired something back — a secondary radiation whose character, Barkla found through careful experiments across the first decade of the twentieth century, was entirely determined by the element being struck. Each element emitted secondary X-rays at wavelengths uniquely its own, a kind of invisible fingerprint written in the electromagnetic spectrum. Barkla called these characteristic X-rays, and he mapped them with the patience of a man who believed the periodic table was hiding a secret it would eventually have to give up. He was right. The discovery gave chemists and later engineers a non-destructive way to identify materials by their elemental composition — a technique now embedded in everything from airport security scanners to archaeological analysis of ancient pigments. The element speaks, if you know the frequency to listen for.

Nobel Prize in Literature

Two Danes, One Uneasy Mirror

Karl Gjellerup · Henrik Pontoppidan

The 1917 prize was shared between two Danes who had almost nothing in common save their nationality and the committee's apparent reluctance to choose. Karl Gjellerup had spent much of his adult life in Germany, writing verse and philosophical novels soaked in a Schopenhauerian idealism that his contemporaries found admirable and few now read. Henrik Pontoppidan was the earthier figure — a realist of considerable power, chronicling the disappointments of Danish provincial life, the rot beneath Lutheran respectability, and the exhaustion of men who had believed in causes that quietly betrayed them. His multi-volume sequences, particularly the saga known in English as Lucky Per, follow a protagonist whose ambitions and moral compromises feel very much like a society examining itself in an unflattering mirror. The war was well underway, Sweden was neutral, and the committee awarded the prize to men writing about the difficulty of living well in a world that offers few reliable guides. The pairing was odd. The choice, in retrospect, was not without intelligence.

Nobel Peace Prize

A Minimum of Humanity, Maintained

International Committee of the Red Cross

The International Committee of the Red Cross received the Peace Prize in 1917 while the war it was trying to manage was still consuming roughly ten thousand men a day. It had been doing so since 1914 — visiting prisoner-of-war camps, negotiating access, coordinating medical relief across front lines that shifted and vanished and reappeared, carrying messages between families who had lost track of each other in the chaos of mobilisation. The prize acknowledged not a peace achieved but a minimum of humanity maintained, which was, under the circumstances, no small thing. The ICRC would receive the prize again in 1944, also during a world war, also in recognition of work done rather than harm prevented — a distinction the committee had learned to live with. What the prize could not do was speed up the armistice, and what the ICRC could not do was make the combatants want one.

Rutherford achieves first artificial nuclear transmutation

Alchemy, Accomplished Without Mysticism

Ernest Rutherford had already dismantled the plum-pudding model of the atom in 1909, demonstrating that nearly all its mass was packed into a tiny nucleus surrounded by empty space, and by 1917 he was in the business of probing that nucleus directly. Firing alpha particles at nitrogen gas, he detected the emission of hydrogen nuclei — particles punched free from the nitrogen by the collision and emerging with a range inconsistent with simple scattering. He had converted nitrogen into oxygen, releasing a proton in the process, and had done so entirely by hand in a laboratory at McGill and then Manchester. Rutherford called the proton a constituent of every atomic nucleus, and his experiment was the first deliberately engineered nuclear transmutation — alchemy accomplished without mysticism or error. The distinction matters because it meant that atomic nuclei were not inviolable, that they could be rearranged by sufficient force, and that the constituents inside them could be catalogued. The rest of the century's physics, including parts of it Rutherford would have found troubling, followed from there.

Einstein introduces stimulated emission

A Curiosity That Waited Forty Years

In 1917, Albert Einstein published a paper on the quantum theory of radiation that most physicists read, noted with respect, and set aside. He described three ways an atom could interact with light: it could absorb a photon and jump to a higher energy state; it could spontaneously emit a photon as it fell back down; or — and this was the new part — it could be triggered by an incoming photon to emit a second, identical photon travelling in exactly the same direction and phase. This last process, stimulated emission, seemed like a theoretical curiosity. The population of excited atoms required to make it useful appeared unachievable; ordinary thermodynamics worked against it. It took until 1960, when Theodore Maiman built the first working laser, for stimulated emission to become a practical mechanism rather than an elegant equation. Today it cuts steel, corrects eyesight, measures the distance to the moon, reads barcodes, transmits internet traffic down optical fibres, and does a remarkable number of things that would have struck a 1917 physicist as pure science fiction. Einstein filed the idea and moved on to other problems.

Félix d'Hérelle discovers bacteriophages

Perfect Circles of Emptiness

Félix d'Hérelle was a largely self-taught Canadian microbiologist working at the Pasteur Institute in Paris when he was asked to investigate a dysentery epidemic running through French troops outside Paris in 1917. Filtering samples from recovering patients and spreading them across bacterial cultures, he noticed something that most experimenters would have dismissed as contamination: clear plaques, perfect circles of emptiness in the bacterial lawn where every microbe had died. A virus, he concluded — one that could pass through the finest porcelain filters and whose sole host was the bacterium itself. He named it bacteriophage, from the Greek for eater of bacteria, and grasped immediately that a predator of pathogens was potentially a therapeutic agent, a living antibiotic that would hunt its target as long as any target remained. The idea did not travel well to the West, where antibiotics overtook phage therapy in the mid-twentieth century and the field was largely abandoned — except in Soviet Georgia, where it never stopped. Now, as antibiotic-resistant bacteria make the pharmacological cupboard look increasingly bare, d'Hérelle's insight is being reconsidered with the urgency it probably deserved all along.

D'Arcy Thompson publishes 'On Growth and Form'

A Nautilus Shell Obeys the Same Math as a Soap Bubble

D'Arcy Wentworth Thompson was a classicist who became a zoologist and managed, in 1917, to produce a book that belonged fully to neither discipline and has disturbed both ever since. On Growth and Form argued, at considerable and beautiful length, that the shapes of living things — the logarithmic spiral of a nautilus shell, the branching geometry of a coral colony, the curvature of a horn, the proportions of a vertebra — are not the accidental products of evolutionary history alone but expressions of the same mathematical forces that shape soap bubbles and river deltas. Biology, Thompson insisted, had been so entranced by Darwin that it had forgotten to ask whether physics had anything to say. The book is long, erudite, wilfully digressive, and written in prose of unusual elegance for a scientific text. Specialists in biology found it philosophically interesting but experimentally thin; mathematicians found it suggestive but informal. Neither could quite dismiss it, and neither has. It has never been out of print, which is the quiet revenge of a book that was never quite at home anywhere.