But in the hours before this tenth of a second, what was life on Earth doing? Was every single living being doing nothing but swimming, roaming around, breeding and sleeping for… well… billions of years? Was every other organism universally and unremittingly stupid – for aeon after aeon? Of the countless branches on the tree of life, was our small twig really the only one to have been graced with the light of intelligence? It seems unlikely.

Nevertheless, for a germ of intelligence to grow into a great civilisation is no easy feat. It requires that many conditions be met simultaneously, a one-in-a-million coincidence. Nascent intelligence is as precarious as a tiny flame in an open field. It’s liable to be snuffed out in the slightest breeze, and even if it does catch and manages to set the surrounding weeds alight, the little fire will likely find its path blocked by a stream or an empty clearing, causing it to die out without so much as a whimper. Should it somehow muster sufficient energy and spread like wildfire, a heavy rainstorm will probably extinguish it. All in all, the chances of a tiny flame becoming a raging conflagration are exceedingly slim. And so we can assume that, through the endless night of antiquity, budding intelligences flickered on and then off again like the brief, brilliant twinkles of fireflies.

At approximately twenty minutes to midnight – that is, approximately twenty minutes before our arrival – two flames of intelligence appeared on Earth. We might call them bright sparks. This twenty-minute period was no mere flash in the pan, for it equates to more than 60 million years. It’s an era unimaginably distant from ours. Humanity’s ancestors would not emerge for another few tens of millions of years. There were no humans back then, and even the continents were shaped very differently than they are today. On the geologic timescale, it was the Late Cretaceous period.

At that time, gigantic animals called dinosaurs inhabited Earth. There were many different types of dinosaurs, and most of them were ludicrously large. The heaviest weighed 80 tonnes, or as much as 800 people, and the tallest grew to thirty metres, the height of a four-storey building. They had already lived on Earth for 70 million years, which is to say that they appeared on Earth more than a billion years ago from now.

Compared with humanity’s several hundred thousand years on Earth, 70 million years is a very long time indeed. Time enough for the patter of raindrops drip-dripping steadily onto the same spot to carve great chasms out of the Earth; time enough for the gentlest of air currents blowing continuously against a mountain to level it. A species undergoing continual evolution over the same timespan, no matter how stupid to begin with, will become intelligent. And that’s what happened to the dinosaurs.