The first mass extinction on earth occurred around 2.5 billion years ago, when a photosynthesizing bacterium appeared and released so much oxygen into the atmosphere that anaerobic life was largely wiped out. This is often called the Great Oxygenation Event, the Oxygen Catastrophe, or the Oxygen Holocaust. 

According to sixth-century-bc Greek poet Hipponax of Colophon, in times of drought, famine, or plague an ugly or deformed person was chosen by the community to be pharmakós, or scapegoat. After being fed figs, barley cake, and cheese, he would be struck on the genitals with the bulbs and twigs of wild plants, led on a procession accompanied by flute, and burned on a pyre. His ashes were thrown into the sea. It is believed that Hipponax, whom Pliny the Elder once called “notoriously ugly,” may have been exaggerating the ritual.

The opening of a particle accelerator at Brookhaven National Laboratory in 2000 inspired fears that high-speed collisions might launch a chain reaction that could turn the earth into a hyperdense sphere about one hundred meters across. A risk calculation determined this to be unlikely; if the collider were to run for ten years, the chance was no greater than 1 in 50 million. “The word unlikely, however many times it is repeated,” wrote concerned scientists, “just isn’t enough to assuage our fears of this total disaster.”

“Pompeii like any other town,” Herman Melville wrote in his journal during an 1867 visit. “Same old humanity. All the same whether one be dead or alive. Pompeii comfortable sermon. Like Pompeii better than Paris.”

Plutarch related that news of the Athenians’ brutal defeat at Syracuse during the Peloponnesian Wars first came from a stranger who told the story at a barbershop “as if the Athenians already knew all about it.” When the barber spread the news, city leaders branded him a liar and an agitator. He was “fastened to the wheel and racked a long time.” Official messengers later came with the “actual facts of the whole disaster,” and the barber was released.