Martin Rees has a fresh perspective on how we humans think about time. A professor of cosmology and astrophysics at Cambridge, Rees is also president (as Isaac Newton once was) of the Royal Society.
His thoughts on how the times are changing appear in the 2009 anthology What Have You Changed Your Mind About? (a terrific book – see first comment, below) published by the Edge Foundation – with an introduction by Brian Eno, of all people.
To our medieval ancestors – say, in the 1300s or 1400s – the entire lifespan of civilization, the world, the universe, everything under creation, seemed vaguely to stretch out over a few thousand years. Except for a handful of learned monks, hardly anyone thought about it. People didn’t expect much to change in their lifetimes, and they were right.
A cathedral might take 200 years to build (Chartres took 600), but a worker cutting stones for its walls knew that eventually someone just like him would be attending services there and hearing the liturgy sung in Latin.
We now know that the universe is 13.7 billion years old – and that our sun has another six billion or so years to burn — but we are no longer capable of looking ahead 200 years, as a 14th century stonecutter could, or even 20 years. Everything is shifting radically within our own lifetimes. Civilization-changing innovations such as moon shots, CDs, PCs, or cellphones blaze like super novae and are then eclipsed within a decade or two. Planners of a half-mile high building in China expect to construct it in four months, with a coffee shop (not a tea house) at the top. But plans are suddenly suspended because more Chinese skyscrapers are rising within three years than all the European cathedrals built in any three centuries of the middle ages — and officials aren’t sure there will be enough entrepreneurs to worship there.
In the long view, the times will keep on changing, and so will we. As Rees puts it:
“Any creatures witnessing the sun’s demise six billion years hence won’t be human; they could be as different from us as we are from a slime mold.”
Not only is everything transforming at a frantic pace, for the first time it is we humans who are making the changes – for good or ill, by accident or by design — altering Earth’s climate and its sea levels, modifying the genetic blueprints of plant and animal life, enlisting millions of robots into the workforce, engulfing humanity with a tsunami of instant information, misinformation, and disinformation. Says Rees:
“What will happen depends on us.”
Along with the ominous implications of such a prospect, the professor sees some hopeful signs. Climate change is getting real attention. For radioactive waste sites, governments now require that they be secure for 10,000 years.
“We are custodians,” Rees concludes, “of a posthuman future – here on Earth and perhaps beyond – that cannot just be left to writers of science fiction.”