Debunking Space Colonization

Here’s a quick survey. Please determine whether you agree or disagree with the following statement: space colonization is feasible with today’s current and emerging technologies.

If you said “agree,” you probably haven’t read The High Frontier, Redux by Charles Stross. If you did and you still think you’ll be sipping margaritas on an alien beach in your lifetime, there’s some wonderful literature on denial around the internet. I suggest you read it and seek professional help if you’re still having trouble facing reality.

The point of the article is simple. Charlie takes into account known facts about the distance to the nearest objects outside our solar system and then calculates the time and energy of getting a human being there. It’s math, pure and simple, and it makes the whole prospect of space colonization seem pretty silly. Here are a few of my favorite tidbits:

Here’s a handy metaphor: let’s approximate one astronomical unit — the distance between the Earth and the sun, roughly 150 million kilometres, or 600 times the distance from the Earth to the Moon — to one centimetre…

Our planetary solar system is 30 centimetres, roughly a foot, in radius. But to get to the edge of the Oort cloud, you have to go half a kilometre, roughly a third of a mile.

Next on our tour is Proxima Centauri, our nearest star… just under two and a third kilometres, or two miles (in old money) away from us.

But Proxima Centauri is a poor choice, if we’re looking for habitable real estate. While exoplanets are apparently common as muck, terrestrial planets are harder to find; Gliese 581c, the first such to be detected (and it looks like a pretty weird one, at that), is roughly 20.4 light years away, or using our metaphor, about ten miles.

Try to get a handle on this: it takes us 2-5 years to travel two inches. But the proponents of interstellar travel are talking about journeys of ten miles.

Is outer space sounding big enough to you yet? It boggles my mind how my fellow nerds, who no doubt already know and understand these numbers, can believe that space colonization is even remotely achievable. I guess there must be some truth to the statement that book smarts and practicality are often mutually exclusive.

It gets even better when Charlie starts talking about the energy required to cover the distance:

So we require the equivalent energy output to 400 megatons of nuclear armageddon in order to move a capsule of about the gross weight of a fully loaded Volvo V70 automobile to Proxima Centauri in less than a human lifetime. That’s the same as the yield of the entire US Minuteman III ICBM force.

For a less explosive reference point, our entire planetary economy runs on roughly 4 terawatts of electricity (4 x 1012 watts). So it would take our total planetary electricity production for a period of half a million seconds — roughly 5 days — to supply the necessary va-va-voom.

Of course, as Charlie points out, these are nice numbers that assume a perfectly efficient propulsion system that doesn’t have to carry fuel. Furthermore, you still need five times as much energy to get to Gliese 581c; this’ll only get you as far as Proxima Centauri.

Charlie also goes on to talk about the difficulties inherent in colonizing other planets within our solar system, but I consider this his most conclusive statement:

The long and the short of what I’m trying to get across is quite simply that, in the absence of technology indistinguishable from magic — magic tech that, furthermore, does things that from today’s perspective appear to play fast and loose with the laws of physics — interstellar travel for human beings is near-as-dammit a non-starter.

It’s nice to hear the argument put to rest so eloquently, especially by a science fiction writer who should, by all rights, be a proponent of space colonization. Let’s face it, though; boring as Earth may be, we’re pretty much stuck here, all science fiction to the contrary.