1940

When war broke out in 1939, no one imagined that this conflict would radically transform our relationship with calculation and information. Hitler invaded Poland, the world tilted, and in the shadows of general staffs, an equally decisive battle began: the battle of intelligence.

Bletchley Park manor, a few miles from London, housed a secret that would change history. Alan Turing designed machines capable of decoding messages encrypted by Enigma, that reputedly unbreakable system used by the Germans. Cryptanalysis, a confidential science until then, became a vital issue. The electromechanical "bombes," primitive ancestors of computers, ran day and night. Deciphering enemy communications saved thousands of lives and would have shortened the war by two years, according to some historians.

Meanwhile, the American army struggled with its ballistic calculations, too complex to be solved by hand, which slowed weapons production. At the University of Pennsylvania, a team worked relentlessly on a crazy project: ENIAC. This 30-ton machine, with its 18,000 vacuum tubes that heated like embers, consumed 200 kilowatts of electricity to calculate shell trajectories in seconds. When it was first powered on in 1946, the war had been over for months, but the era of electronic computing had just begun.

Women played a strangely forgotten role in this story. Six female mathematicians programmed ENIAC by physically reconfiguring its circuits. They invented, unknowingly, the profession of programmer. They were Kay McNulty, Betty Snyder, Marlyn Wescoff, Ruth Lichterman, Betty Jean Jennings, and Fran Bilas. Their names deserve to appear in history books alongside the engineers who assembled the machine.

The post-war period sketched a new landscape where the United States, virtually untouched by combat, now possessed 50% of the world’s wealth. American industry ran at full capacity to rebuild devastated Europe. IBM’s punched card machines equipped administrations and large companies, but their limitations quickly became apparent in the face of exploding calculation needs.

In the scientific world, a young Bell Labs engineer, Claude Shannon, published "A Mathematical Theory of Communication," a 1948 article that would almost go unnoticed. In it, he demonstrated that any information could be treated as a sequence of 0s and 1s. This deceptively simple idea would revolutionize our civilization.

The Cold War settled in and pushed both superpowers to invest in research. In Moscow, Sergei Lebedev worked secretly on MESM, the first Soviet computer. The Americans multiplied projects: Whirlwind at MIT, IAS at Princeton, Mark III at Harvard. John von Neumann theorized an architecture that would remain the standard for more than half a century. Memory circuits improved, vacuum tubes gave way to transistors invented in 1947.

In the innovative world of telecommunications, AT&T expanded its automatic telephone network. Undersea cables multiplied. In laboratories, digital data transmission was being experimented with. These technologies would eventually converge with computing.

Universities created their first "automatic computing" departments. New vocabulary emerged: programming, algorithm, bit, byte. Commercial machines appeared. Ferranti released its Mark I in Great Britain. Konrad Zuse, in Germany, created the first European computer company. Remington Rand delivered UNIVAC I to the American Census Bureau in 1951.

Libraries and documentation centers, overwhelmed by the explosion of post-war scientific literature, sought new solutions. The universal decimal classification showed its limits. Theoretical work on automated documentation systems emerged. Vannevar Bush, in his famous 1945 article, imagined an office equipped with a "Memex," a machine capable of storing and linking documents through associations, a troubling prefiguration of the Web we know.

Computing did not yet exist as a discipline; people spoke of cybernetics, a term proposed by Norbert Wiener in 1948 to designate the science of control and communication. In France, IBM translated "computer" as "ordinateur," on the suggestion of Professor Jacques Perret. The term quickly took hold in the Francophone world.

Who could have predicted, in 1940, that ten years later, electronic machines would process information at dizzying speed? These early achievements, despite their monumental size and exorbitant cost, would transform every aspect of our daily lives in the following decades.

The desire to create thinking machines was nothing new. Pascal and Leibniz had built mechanical calculators in the 17^th century. Babbage had designed his analytical engine in the 19^th. But it took the urgency of war, massive state investment, and collaboration between universities and industries for the dream to become reality. The modern computer was born from this complex alchemy where military necessity, mathematical research, and electronic engineering intertwined.

In 1950, computing was barely emerging from its prehistory. Machines were enormous, fragile, costly. Only a few initiates understood their operation and possibilities. Yet the path to digital transformation was laid out. The theoretical and technical foundations were established. The first civilian applications appeared.

The adventure that was beginning would last longer than most technological revolutions. Seventy-five years later, we live in the wake of this transformation. The computer, a child of war turned universal tool, continues to modify our relationship to knowledge, work, and communication. Its history truly begins in the 1940s, when men and women, facing the challenges of a world in flames, invented thinking machines.

At the dawn of the 1950s, a page turned. Pioneers gave way to industrialists. Fundamental research stepped back before practical applications. Computing entered its commercial phase. Names like IBM, Remington Rand, Ferranti, and Bull established themselves. A new industry took flight, driven by the growing needs of a booming economy. No one suspected the scale of the upheavals to come.