Free Radicals - Michael Brooks [14]
Would other scientists have got there eventually, without such an irrational inspiration? It’s not clear that they would. The British had tried and failed for years, as had the Russians. The successful Russian reactor design is a carbon copy of the American prototype, obtained through espionage rather than inspiration.
Snyder said that he didn’t believe there was anything about this incident that made him special: similar processes of revelation were happening all around him. In fact, several major developments in physics that made the bomb possible occurred as a result of an irrational, unpredictable – some would say unscientific – moment of revelation or inspiration.
Take the experience of Snyder’s boss at the Manhattan Project, for example. The physicist Enrico Fermi, a defector from Mussolini’s Fascist Italy, was the man charged with building the nuclear reactor. Back in Rome, in October 1934, Fermi had experienced a similarly inexplicable breakthrough – one that led directly to the atomic bomb. He had been trying to understand nuclear reactions. He and his team were trying to induce radioactivity by bombarding a metal target with neutrons, but there was neither rhyme nor reason to their results: there seemed to be no way to predict what would happen in any particular experiment.
One day, on the way into work, Fermi decided to try putting a block of lead in front of the target. The notion in his head was that the lead might filter out the slowest of the neutrons and allow a more controllable bombardment. He commissioned the physics department’s machinists to make the lead block. Contrary to his usual style, he gave them an extremely detailed description of what he wanted, and the block was fabricated to his requirements. What happened next was, as with Snyder’s experience, inexplicable – and yet of phenomenal consequence.
For some reason he couldn’t fathom, Fermi felt that he didn’t want to use the lead block. For two days he let it sit, awaiting collection, in the machine shop. When he eventually had it brought to his laboratory, he still dithered. This is how he later recounted the story to the astrophysicist Subrahmanyan Chandrasekhar:
I was clearly dissatisfied with something: I tried every ‘excuse’ to postpone putting the piece of lead in its place. When finally, with some reluctance, I was going to put it in its place, I said to myself: ‘No! I do not want this piece of lead here; what I want is a piece of paraffin.’ It was just like that: with no advanced warning, no conscious, prior, reasoning. I immediately took some odd piece of paraffin I could put my hands on and placed it where the piece of lead was to have been.
Using the paraffin turned out to be an extraordinary stroke of anarchic genius. Fermi and his collaborators watched as the radioactivity induced in their silver target rose by 50 per cent. They soon realised that the hydrogen molecules in the paraffin were slowing the neutrons and giving them far more opportunity to interact with the silver atoms – creating radioactive elements – before they emerged on the other side. Such slow neutrons are now known to be the essential component of a reliable nuclear reaction. Fermi’s discovery won him the 1938 Nobel Prize in Physics and, arguably, it won the Allies the Second World War.
Were Snyder and Fermi’s experiences unusual? Yes, in that scientists do not make such significant discoveries every day. But if we restrict ourselves to the realm of significant scientific discoveries, the answer seems to be no: they invariably come from apparently nowhere.
Many of the scientists who have experienced such revelations feel humbled by them, and even question whether they should receive credit for the discovery;