In 2010, Cambridge physicist Stephen Hawking made headlines by proclaiming on his documentary miniseries, Stephen Hawking’s Universe, that the Search for Extraterrestrial Intelligence (SETI) is a bad idea because it may end up attracting unwanted attention – interstellar alien travellers who will want our resources, and will be far more advanced than us than the 15th-century Spaniards were when they splashed ashore in the Caribbean. And, as Hawking points out, that encounter didn’t end well for Native Americans.
There are compelling reasons why Hawking’s fears may be exaggerated, but they are worth considering. In any case, Hawking’s worries about alien scavengers lurking beyond the solar system, capturing stray signals from intelligent civilizations, do not mean that he is opposed to exploring space more generally – as you might expect from one of the world’s most-recognized writers on cosmology and black holes. Instead, Hawking is a passionate advocate of some of the most speculative and far-seeing schemes for the future human exploration of the universe around us, beginning in our own backyard, the solar system.
According to Hawking (who, it must be admitted, does have something of a vested interest in the matter), increased budgets for space exploration aren’t just a way of keeping highly educated scientists and aeronautical engineers employed: it’s an insurance policy. Life on Earth, says Hawking, “is at an ever-increasing risk of being wiped out by a disaster such as sudden global warming, nuclear war, a genetically engineered virus or other dangers.”
This means humanity needs to start preparing for the worst, and developing the technology we would need both to protect Earth from threats like rogue asteroids, and also, ultimately, to keep ourselves alive somewhere else, without relying on mother Earth at all. Hawking has suggested that the “premium” on this so-called insurance policy should be 0.25% of world GDP per year, equivalent to about $150 billion. That’s an order of magnitude bigger than NASA’s current budget – but, as Hawking would probably point out, if we can spend several times that on the military to fight the threats of today, we should also be thinking about investing against the threats of tomorrow.
How we might go about spending this money is another matter. The Obama administration has deep-sixed NASA’s plans for new manned Moon missions. (Space-watchers long saw this coming, since the Bush administration also failed to devote enough resources to actually make the trip a reality.) Hawking would see us go in the other direction. Rather than a mere “new Apollo,” with brief multi-day trips to the Moon, Hawking thinks our goal should be colonization: first of the Moon, and then of Mars. Mars has water ice at its poles which could be melted for future travellers.
From there, the sky is the limit – literally. If human technology can catch up with Hawking’s vision, he would have us spread out into our galactic neighbourhood, sending spacecraft – first probes – to nearby stars with planets that seem most similar to our own. Within a few centuries humanity would be capable of doing this. The first spacecraft would not be the warp-capable starships envisioned by idealistic popular science fiction like Star Trek, however. The best we can imagine today involves slow, hulking spacecraft taking centuries to make an interstellar trip. Still, assuming they could make the trip intact, they would still qualify as starships.
Unsurprisingly, a man who has spent his career attempting to interest the public in time, black holes, and some of the most ephemeral concepts in scientific cosmology doesn’t want to limit his imagination to mere starships. If we could accelerate a spaceship to nearly the speed of light, he announces on the same show as his previous controversial claim, we could effectively travel forward in time, potentially for millions of years. We could use these timeships to skip forward in time, escaping devastation on Earth while our planet slowly recovers from centuries of pollution and resource depletion.
To Hawking, the next century is critical. “It is important for the human race to spread out into space for the survival of the species,” he says. In the next few decades, humanity will either learn to grapple with some fundamental threats to its survival (like climate change, resource depletion, and war), or it will probably have run through too much of Earth’s resources to solve those problems and still have enough left over to jump-start our expansion into the galaxy.
Of course, if humanity ever does build starships – or timeships – none of us who are alive today will be there to see it. For himself, Hawking’s goals are a little more limited: he’s been waiting for Virgin Galactic’s SpaceShipTwo to start commercial operations, so that he can go to space.