Here’s a couple of questions to consider: If humanity were somehow to disappear from Earth tomorrow, would it really matter? If no life form conscious of the universe existed, would the universe still exist?
These are questions that properly belong to philosophy and religion, but they also lie at the heart of “Big History,” a form of inquiry that’s emerged over the past decade. Whereas traditional history limits itself to the past 5,000 years or so, for which we have written records, and focuses on the transient and often inconsequential actions of individuals and nations, Big History instead sets the human story within the larger context of life on Earth. In doing so, it also compels us to consider our own future.
To appreciate why, it’s first necessary to recall the basic framework for the study of human history that has prevailed until now.
For centuries, western civilization’s sense of historical time was rooted in biblical chronology. One result of this was youthful estimates of the Earth’s age. In 1658, Archbishop James Ussher calculated the day of creation to have been October 22, 4004 BC. Six thousand years was ample time to contain all of human history, it seemed.
By the late 1700s, however, advances in geology had thrown this orthodoxy into question, as engineers and miners dug deep into the Earth in the industrial revolution’s quest for coal and other minerals. Six thousand years simply wasn’t enough time to account for the variation in rock formation they encounted.
Two generations later, Darwin’s theory of evolution — a process that required many thousands if not millions of years — banged a final nail into the coffin of Ussher’s estimate. “The whole history of the world, as at present known,” Darwin wrote in The Origin of Species, “will hereafter be recognized as a mere fragment of time, compared with the ages which have elapsed since the first creature… was created.”
Darwin suggested an age of several hundred million years for the Earth, but not even he could have foreseen how far the new science of cosomology would advance that figure in the 20th century. With amateur astronomer Edwin Hubble’s discovery that the universe was still expanding, it followed logically that there must have been a time long ago when the universe had first begun to expand: the moment of the big bang. By the late 20th century, scientitists placed this event — the birth of the universe — at 13.7 billion years ago. At the same time, new estimates for the Earth gave it an age of 4.6 billion years, more than 750,000 times Bishop Ussher’s figure.
What’s all this got to do with history? Well, imagine compressing the entire existence of the Earth into a single year, starting January 1. On that scale, our own arrival comes later than you might think:
First multi-celled life — Nov. 10
Age of the dinosaurs -— Dec. 12-26
Appearance of Homo sapiens — Dec. 31, at 11:49 p.m.
Start of recorded history — Dec. 31, 11:59 and 34 seconds
In other words, human history as traditionally studied begins just as the party poppers are about to go off for the start of another year. Far from being the central focus of terrestrial history, we appear almost as an afterthought. It’s this new perspective that Big History provides, allowing us to stand back from the small and immediate and instead explore how we, as a species, fit in with the far longer reaches of time on Earth.
Naturally, this is a little unsettling for those who believe that humans occupy a privileged position on the planet and, though our consciousness and reflection, give meaning to the universe itself. As cosmologist Paul Davies writes in The Goldilocks Engima, “Other animals observe the same natural phenomena as we do, but alone… Homo sapiens can also explain them…. Somehow the universe has engineered, not just its own awareness, but also its own comprehension.”
This is why Davies subtitled his book Why is the Universe Just Right for Life? “If almost any of the basic features of the universe, from the properties of atoms to the distribution of the galaxies, were different,” he argues, “life would very probably be impossible.” Of course, if that were so, then we wouldn’t be here to notice that fact in the first place, a point Davies concedes. Yet here we are, and so the question remains: does the universe exist as it does precisely to foster the development of intelligent and conscious life (i.e. us)?
Turn the question around. What if we were suddenly to disappear? “If humans are snuffed out in the twinkling of a cosmic eye,” writes Davies, “it may never happen again. The universe may endure for a trillion years, shrouded in total mystery, save for a fleeting pulse of enlightenment on one small planet around one average star… 13.7 billion years after it all began.”
Is this prospect likely? In one sense, our doom is certain. Long before the sun expands into a red giant five billion years from now, the Earth will have become a scorched, airless, uninhabitable orb. However, even more immediately, things don’t look too good. In Our Final Hour, Martin Rees considers the many threats presently facing humanity and offers our chances of surviving even the next century as “no better than 50-50.”
In the event of extinction, what would our legacy be? Not much, according to Alan Weisman in The World Without Us. Imagining our immediate and total disappearance, Weisman estimates that within a few centuries there would remain few signs of our once dominat presence.
And so back to our original questions. Would it really matter if we suddenly disappeared? On one level, not at all, no more than did the extinction of dinosaurs after their reign of 165 million years. Life on Earth would continue, with evolution thrusting forward another dominant species.
On another level, it would matter immensely. As the only life form we know of that is both aware of the universe and has (successfully) struggled to interpret its deepest workings, without humanity the universe would simply be a big, empty fridge.
