Newt Gingrich was the subject of much mockery this week when he proposed a permanent lunar colony by the end of his second term. Perhaps he was joking when he said one day it could be the 51st state. But, there are plenty of people who, while they may be dubious of Newt Gingrich's ability to lead us into space, take it as an article of faith that mankind will some day leave the Earth and colonize the moon, then other planets, then move on beyond our solar system to explore and exploit other solar systems.
I, alas, am dubious, though with caveats. First, "some day" is a vague time frame. I'm ill prepared to speculate what mankind might accomplish in, say, 5000 years, let alone 50,000 years, or 5 million years. But, a lot of science fiction envisions our civilization spreading off the earth in this century. Indeed, a lot of science fiction imagined it taking place in the LAST century. Plenty of science fiction imagined us having moon bases and Mars colonies by 1999. By 2012, we were going to be shuttling back and forth to Saturn. I talk to a lot of people at science fiction conventions who feel like, if only politicians would get their priorities straight, we could be setting up shop on Mars by the end of the decade. For now, I'll just say that it's difficult for me to imagine any permanent base of any significance by the end of this century.
Caveat two: "Of any significance." Obviously, we HAVE a space station. We had a space shuttle. We made it to the moon. I don't doubt that China or India or even the US might go back to the moon for a visit as a matter of national pride. Maybe we'll get our act together enough to pay a visit to a nearby asteroid. But the kind of "city of wonders in the sky" space station of science fiction is difficult to foresee within the next 100 years. "Cramped RVs parked somewhere between here and the moon," maybe.
Caveat three: I'm only talking about human space flight. Obviously, we've done amazing stuff with rovers, probes, and telescopes. I anticipate the trend will continue. We might be stuck on the planet, but our tools can really travel.
That third caveat, by the way, is the real reason I don't think humans will be heading for another planet anytime in the coming century. The weak point in "manned space flight" is the "manned" part. We simply aren't engineered well for traveling to another planet. Humans have absolutely horrific fuel consumption, we generate a tremendous amount of waste, we are overly complicated and prone to breakdowns. Our sensory arrays are a mess. Our one tiny advantage over machinery is our ability to behave erratically. Mars rovers aren't likely to head for a funny-looking rock on a whim, kick it over, and by chance find some kind of martian worm. But, while our ability to behave randomly and benefit from lucky outcomes may have a huge evolutionary advantage here on earth, outside the bubble of our own biosphere, it's more likely to get us killed.
Consider interstellar travel. When science fiction authors contemplate it, they have to resort to magic to move humans through the void at speeds not just faster than light, but faster than boredom. If it takes the Enterprise five years to get from star to star, Kirk doesn't get to sleep with too many alien babes before he becomes to fat and bald to be a player. Some science fiction writers do tackle this issue by introducing generations ships which are basically self contained worlds. But, trying to move a human biosphere across the void requires a stunning amount of resources compared to moving a robot the size of my cell phone from here to another planet.
Any argument I've ever heard for us leaving the earth seems either self-negating or better tackled by leaving humans out of the equation.
Popular arguments are:
1. We have to leave because a collision is inevitable. We need only look at our moon to see that massive collisions do occur in our neck of the woods. But, unless the object is truly massive, I don't see how evacuating the planet is a superior approach to using robots to intercept the threatening object and steer it away.
2. We will find some resource out there that not here.
Suppose the thing we desire is information. Machines can go wherever we need them to and gather the data we need. If a machine can't go there, we can't go there. Suppose the thing we need is some exotic mineral. The main problem here is that we understand the periodic table pretty well, and any exotic mineral we need is either here already, or else so unstable that it's going to vanish from wherever else it might be found. If we understand chemistry at all, then the same building blocks of nature are going to be found all over the universe. They don't have anything in the Andromeda galaxy we can't put our hands on here. Of course, some matter is more interesting than other. Suppose we get lucky enough to discover life on another world, either Mars or Europa. Yay! The impulse to go and study would be strong.
And that impulse would absolutely have to be resisted. Because if we do find another ecosystem, I can think of nothing more irresponsible than to place a human in the middle of it. Suppose we flew a spaceship filled with humans to Europa. It's a well built machine, with an artificial ecosystem capable of supporting us. Since we can't pack enough food for the journey, we probably have some sort of algae and brine shrimp farming going on, possibly in combination in recycling our waste. Now imagine this ship gets whacked by a rock the size of softball a mile above the surface, and we suddenly spray brine shrimp and algae and human excrement over a hundred mile swath of ice. Then the ship smashes into the surface, and the liquefied remains of the crew seep into the cracks we've opened in the ice. We would have forever contaminated the very thing we went there to examine, an ecosystem untouched by man.
3. We have to leave our planet because we'll outgrow it. You don't have to be blind to see that we are placing severe ecological stress on our planet. We are altering the atmosphere, acidifying the oceans, and creating entire islands of waste plastic. We suck nutrients from the soil by growing crops in places they were never designed to grow. And, we're starting to get really packed in. It's tempting to look at Mars, and dream of a little elbow room. But, honestly, is the fact that we've screwed up our current ecosystem a good argument for leaving it behind, the way Newt Gingrich might abandon a sick wife? Or, couldn't the money and energy spent on a hypothetical mission to Mars be used instead to clean up some of the crap we've dumped in our seas?
The fact is, our current technology is capable of building a space probe and sending it to another solar system. Perhaps the journey would take fifty thousand years. Obviously, we aren't going to spend money on a project that requires so long for a payoff. But, the weak link here is the human need to see results of a project in our own lifetime. On the scale of the universe, fifty thousand years is just a blip.
Perhaps one day we'll beat death, and a race of immortal humans will be able to plan projects that span thousands of years. If not us, then the better designed beings that follow us.
For now, we're stuck with this world, and we're stuck with our fellow men. I advise we take care of both.