4. Tocsin

No one heard the first tolling of Earth’s funeral bell — not even the scientists who made the fatal discovery, far underground, in an abandoned Colorado gold mine.

It was a daring experiment, quite inconceivable before the mid-twentieth century. Once the neutrino had been detected, it was quickly realized that mankind had a new window on the universe. Something so penetrating that it passed through a planet as easily as light through a sheet of glass could be used to look into the hearts of suns.

Especially the Sun. Astronomers were confident that they understood the reactions powering the solar furnace, upon which all life on Earth ultimately depended. At the enormous pressures and temperatures at the Sun’s core, hydrogen was fused to helium, in a series of reactions that liberated vast amounts of energy. And, as an incidental by-product, neutrinos.

Finding the trillions of tons of matter in their way no more obstacle than a wisp of smoke, those solar neutrinos raced up from their birthplace at the velocity of light. Just two seconds later they emerged into space, and spread outward across the universe. However many stars and planets they encountered, most of them would still have evaded capture by the insubstantial ghost of ‘solid’ matter when Time itself came to an end.

Eight minutes after they had left the Sun, a tiny fraction of the solar torrent swept through the Earth — and an even smaller fraction was intercepted by the scientists in Colorado. They had buried their equipment more than a kilometre underground so that all the less penetrating radiations would be filtered out and they could trap the rare, genuine messengers from the heart of the Sun. By counting the captured neutrinos, they hoped to study in detail conditions at a spot that, as any philosopher could easily prove, was forever barred from human knowledge or observation.

The experiment worked; solar neutrinos were detected. But — there were far too few of them. There should have been three or four times as many as the massive instrumentation had succeeded in capturing.

Clearly, something was wrong, and during the 1970s the Case of the Missing Neutrinos escalated to a major scientific scandal. Equipment was checked and rechecked, theories were overhauled, and the experiment rerun scores of times — always with the same baffling result.

By the end of the twentieth century, the astrophysicists had been forced to accept a disturbing conclusion — though as yet, no one realized its full implications.

There was nothing wrong with the theory, or with the equipment. The trouble lay inside the Sun.

The first secret meeting in the history of the International Astronomical Union took place in 2008 at Aspen, Colorado — not far from the scene of the original experiment, which had now been repeated in a dozen countries. A week later IAU Special Bulletin No. 55/08, bearing the deliberately low-key title ‘Some Notes on Solar Reactions’, was in the hands of every government on Earth.

One might have thought that as the news slowly leaked out, the announcement of the End of the World would have produced a certain amount of panic. In fact, the general reaction was a stunned silence — then a shrug of the shoulders and the resumption of normal, everyday business.

Few governments had ever looked more than an election ahead, few individuals beyond the lifetimes of their grandchildren. And anyway, the astronomers might be wrong. Even if humanity was under sentence of death, the date of execution was still indefinite. The Sun would not blow up for at least a thousand years, and who could weep for the fortieth generation?