Sorry, Stephen Hawking — We’re Not Going Anywhere

Stephen Hawking’s views are always worth listening to. His contributions to physics and cosmology have been extraordinary.

But like any oracle, his pronouncements don’t always mean what they seem to mean.

Last November, Hawking suggested we should make humanity an interplanetary species within a thousand years, or we would risk extinction — if not from global warming, then from pandemics, or nuclear war, or an asteroid smashing into us.

Then, early in May, he brought his deadline forward by 900 years. By 2117, when some of today’s toddlers will still be alive, Hawking argues we should have sustainable colonies somewhere in space. The moon, Mars, giant space habitats — without humans living in such places, Hawking said, we could be goners altogether.

This is not exactly a new concept. Ever since Hiroshima and Nagasaki, the possibility of extinction has loomed over us. Scientific advances since then have only taught us to worry more. We could go the way of the dinosaurs if another asteroid hits us. The chemicals we use to make our lives easier are also killing off bees and birds. The fuels we burn, we now know, have pushed carbon dioxide levels to 410 parts per million, a level not seen in millions of years. And bacteria and viruses are becoming resistant to antimicrobial drugs.

Ever since the arrival of the atomic bomb and the Nazis’ V-2 rockets, we’ve imagined escaping into space to start over again on some new world. Ray Bradbury’s novel The Martian Chronicles was all about that (but the colonists, when the Third World War breaks out on Earth, idiotically go home). Any number of science fiction novels have been built on the same gimmick.

But since Bradbury’s time we’ve learned a lot more about our neighbouring planets, and the news is not good.

Mars? You can’t get there from here

First of all, as Canadian astronaut Chris Hadfield recently pointed out, you can’t get there from here, at least with our present level of technology. The Americans’ moon landings were brilliant stunts, but the astronauts spent only hours on the moon — while wearing diapers. It’s tidier spending months on the International Space Station, as Hadfield did, but we still don’t understand all the long-term health effects of living in zero gravity.

Nor do we understand how to move enough people and equipment to the moon to build a permanent station, which would likely have to be built deep under the surface to reduce radiation effects. The moon has water, though probably not as much as we’d like.

Mars, of course, has much more water; it even flows on the surface sometimes. But it does so because it’s too salty to freeze in normal Martian subzero weather. To build a Martian colony, we’d have to move not only excavation equipment but a desalination plant.

We’d also have to know how people in zero gravity for months could still be able to cope even with low Martian gravity (38 per cent that of Earth’s, meaning a hundred-kilo human would weigh just 38 kilos, or 83 pounds).

And whatever the destination, we’d need to ship a lot of people: medical experts, scientists, engineers, agronomists, chemists, and teachers, just for starters. We’d have to ensure that lots of fertile people made it through months of radiation exposure, and we’d also have to ship thousands of frozen fertilized eggs (and millions of animal embryos and plant seeds) with the broadest possible genetic diversity.

The colonists would spend almost all their time underground, digging tunnels, planting crops, creating and sustaining breathable air and drinkable water. They might have 3D printers to build much of their equipment, but those printers would need some kind of feedstock.

They would also be at the mercy of events. A harmless virus might mutate into a killer. A structural flaw might let the water supply leak out. An industrial accident could fill the colony with toxic smoke or chemicals. Years of low gravity could mean brittle bones — so the 3D printers would have to crank out exoskeletons for everyone. A single critical material shortage could spell death for the colony. So could a single internal conflict between colonist groups.

A precarious life

And even if all these hazards and disasters could be overcome, the colonists would lead precarious lives in the human equivalent of an aquarium. They’d live under artificial light, amid whatever plants could survive. Everything the colonists produced, from high technology to excrement to corpses, would have to be recycled.

It would be an extraordinary achievement if the original colonists lived to see their grandchildren, and if those grandchildren grew up capable of sustaining the colony. It would take centuries for the colonies to reach the quality of life we take for granted.

Stephen Hawking certainly understands this prospect as well as anyone. Even if we sent dozens of robot expeditions to Mars or the moon to prepare colonies, he understands we’re unlikely in just a century to build the technology needed for human survival. That’s especially true if we’re simultaneously struggling with global warming, mass die-offs of humans and animals, and dozens of wars for dwindling resources. Such challenges would require precisely the kinds of skilled people we’d need as colonists.

So why has he given us such an impossible deadline? I suspect it’s because Hawking wants us to scare us into our wits. Sending a few hundred or thousand people to a hostile environment in space is just an expensive way to kill them. No matter how bad life gets here on Earth, it wouldn’t require the awful regimentation of life on Mars or the moon. And we would have far more resources here to deal with our problems. The sooner we deal with them, the more resources we’ll have.

Sure, eventually humans will stand on the moons of Jupiter and Saturn, taking selfies. Space stations will orbit Venus and Mars, maybe even Pluto.

But those experiences are still far, far in the future. For the next few centuries, at least, we will live on the planet we evolved for, in whatever mess we have made of it. The real challenge won’t be surviving on other planets; it will be surviving on this one.