Аннали Ньюиц - Scatter, Adapt, and Remember - How Humans Will Survive a Mass Extinction

Without sunlight, agriculture would grind to a halt and wild plants would die back. Herbivores would die, and then the carnivores who fed on them would die out, too. Creatures who dwelled near the surface of the water would suffer in the immediate effects of the hit. Then, over time, runoff from the decimated land would fill the oceans with carbon and create deadly pockets of anoxic waters. Humans would have to rely on greenhouses for food, as well as whatever we could cultivate with little sunlight. Mushrooms, fungus, and insects would play a much bigger role in our diets than they do today.

There is also the distinct possibility that enough people would be killed in the strike that it would be impossible to maintain our civilization at its current level of development and energy needs. Megacities and high-tech societies require many people with specialized knowledge to make them function, and if only a few million people are left alive on the planet, it’s unlikely that we’ll have the right combination of skills to resurrect New York or Tokyo. What would we do if we had to rebuild human civilization from scratch? This is the kind of question that dogs apocalyptic science fiction, but preoccupies people in the real world, too. Alex Weir, a software developer based in Zimbabwe, is part of a small group that maintains the CD3WD database, a relatively small set of computer files that contain as much human knowledge as possible about what amounts to a pre-technological civilization. There are sections devoted to basic medicine, agriculture, town building, and power generation. At 13 gigabytes, it’s easily stored on a few DVDs, or (ideally) printed out as a thick sheaf of papers and stored in a three-ring binder. The idea is to keep the CD3WD database in your survival kit, a backup copy of everything history has taught us about creating an early industrial society. It is one of the simplest and most profound examples of how survival requires us to remember what has come before. If people need guidance with rebuilding the world after the icehouse is over, CD3WD and similar projects can help us restart civilization as quickly as possible.

It is inevitable that the Earth will be on a collision course with a PHO at some point. Obviously, our first duty is to keep mapping the skies, tracking NEOs, and perfecting our asteroid-nudging technologies. But we also need to accept that the Earth isn’t the safest place for us if we want to survive for another million years. We need to scatter to other planets and moons, building structures in space so that even if Earth is wiped out, humanity will survive. That’s why one of the keys to long-term existence involves creating devices that will help us escape the planet. One such device is the subject of the next chapter.

EVENTUALLY WE’LL HAVE to move beyond patrolling our planetary backyard and start laying the foundations for a true interplanetary civilization. Asteroid defense and geoengineering will only take us so far. We need to scatter to outposts and cities on new worlds so that we’re not entirely dependent on Earth for our survival—especially when life here is so precarious. Just one impact of 10 on the Torino scale could destroy every human habitat here on our home planet. As horrific as that sounds, we can survive it as a species if we have thriving cities on Mars, in space habitats, and elsewhere when the Big One hits. Just as Jewish communities managed to ensure their legacy by fleeing to new homes when they were in danger, so, too, can all of humanity.

The problem is that we can’t just put our belongings into a cart and hightail it out of Rome, like my ancestors did when things got ugly in the first century CE. Currently, we don’t have a way for people to escape the gravity well of planet Earth on a regular basis. The only way to get to space right now is in a rocket, which takes an enormous amount of energy and money—especially if you want to send anything bigger than a mobile phone into orbit. Rockets are useless for the kind of off-world commuter solution we’ll need if we’re going to become an interplanetary civilization, let alone an interstellar one. That’s why an international team of scientists and investors is working on building a 100-kilometer-high space elevator that would use very little energy to pull travelers out of the gravity well and up to a spaceship dock. It sounds completely preposterous. How would such an elevator work?

That was the subject of a three-day conference I attended at Microsoft’s Redmond campus in the late summer of 2011, where scientists and enthusiasts gathered in a tree-shaded cluster of buildings to talk about plans to undertake one of humanity’s greatest engineering projects. Some say the project could get started within a decade, and NASA has offered prizes of up to $2 million to people who can come up with materials to make it happen.

The physicist and inventor Bryan Laubscher kicked off the conference by giving us a broad overview of the project, and where we are with current science. The working design that the group hopes to realize comes from a concept invented by a scientist named Bradley Edwards, who wrote a book about the feasibility of space elevators in the 1990s called The Space Elevator . His design calls for three basic components: A robotic “climber” or elevator car; a ground-based laser-beam power source for the climber; and an elevator cable, the “ribbon,” made of ultra-light, ultra-strong carbon nanotubes. Edwards’s design was inspired, in part, by Arthur C. Clarke’s description of a space elevator in his novel The Fountains of Paradise . When you’re trying to take engineering in a radical new direction that’s never been tried before, sometimes science fiction is your only guide.

A space elevator is a fairly simple concept, first conceived in the late nineteenth century by the Russian scientist Konstantin Tsiolkovsky. At that time, Tsiolkovsky imagined the elevator would look much like the Eiffel Tower, but stretching over 35,000 kilometers into space. At its top would be a “celestial castle” serving as a counterweight.

A century after Tsiolkovsky’s work, Bradley speculated that a space elevator would be made of an ultra-strong metal ribbon that stretched from a mobile base in the ocean at the equator to an “anchor” in geostationary orbit thousands of kilometers above the Earth. Robotic climbers would rush up the ribbons, pulling cars full of their cargo, human or otherwise. Like Tsiolkovsky’s celestial castle, the elevator’s anchor would be a counterweight and space station where people would stay as they waited for the next ship out. To show me what this contraption would look like from space, an enthusiast at the Space Elevator Conference attached a large Styrofoam ball to a smaller one with a string. Then he stuck the larger ball on a pencil. When I rolled the pencil between my hands, the “Earth” spun and the “counterweight” rotated around it, pulling the string taut between both balls. Essentially, the rotation of the Earth would keep the counterweight spinning outward, straining against the elevator’s tether, maintaining the whole structure’s shape.

Once this incredible structure was in place, the elevator would pull cargo out of our gravity well, rather than pushing it using combustion. This setup would save energy and be more sustainable than using rocket fuel. Getting rid of our dependence on rocket fuel will reduce carbon emissions from rocket flights, which today bring everything from satellites to astronauts into orbit. We’ll also see a reduction in water pollution from perchlorates, a substance used in making solid rocket fuel, and which the Environmental Protection Agency in the United States has identified as a dangerous toxin in our water supplies.