The ever-interesting Paul Gilster over at Centauri Dreams writes about the argument that we’re as likely to be at the end of human spaceflight as the beginning. In brief, Gilster gives serious consideration to Richard Gott’s view that, due to the Copernican Principle, we have no reason to believe that our time in the universe is special, just as our location in the universe certainly isn’t. Therefore, we have no reason to prefer the idea that we’re at the beginning of a glorious era of spaceflight over the notion that humanities days in space are all but over.

As I see it, Gott makes two fatal errors in his skepticism of human space flight. The first is in his application of cosmic-scale principles to social-scale phenomena, and the second is in embracing ungrounded Rationalism over Empiricism.

The Copernican Principle makes a great deal of sense in cosmic scale systems and on cosmic scales of time. The universe is unspeakably vast and we are adrift somewhere within it. The age of the cosmos is mind-bogglingly long and, in comparison, our species has only been around for a very brief moment.

There’s no reason to think our place in this vastness is unusual. Nor any reason to believe that our few hundred thousand years is better or more preferable to the next few hundred thousand.

But we, as a species, don’t act or live on cosmic scales. We are, to paraphrase Richard Dawkins, “medium-sized objects moving at medium-sized speeds through a medium-sized world”. To apply cosmic-sized principles to us is to commit a Fallacy of Composition. Roughly: “Our place in the cosmos seems to obey principle X, therefore our place in human history must obey principle X.” Human history is a vanishingly small part of cosmic history and just because a principle applies to the whole doesn’t mean it applies to every fragment of it.1

On the second score, Gott embraces the sort of mystical Rationalism that Hume and Kant should have put in the ground hundreds of years ago. Hume is my homeboy, so I’ll focus on his critiques.

Hume accurately pointed out that pure Rationalism has little to no explanatory power. It is essentially the quest for internally-consistent worlds unmoored from the real one. Reason alone cannot accurately predict, for instance, how two billiard balls will behave when they collide. Instead, one needs to have seen billiard balls collide before and used reason to understand the principles involved. Reason, in other words, must serve empirical observation. This was one of the greatest results of the Enlightenment.

Gott commits the sin of pure reason by discarding his observation and saying, well, there’s no purely logical reason why space flight has to move forward. It’s logically self-consistent that we might scrap all our rockets, turn our noses back to Earth, and never seek space again.

Yes. That’s true. But it’s completely unhelpful and as likely to be wrong as it is to be right. That’s because it throws out everything we know about human ingenuity, curiosity, desire, and acquisitiveness. I mean, hell, as we speak there are people seriously trying to solve the problem of mining asteroids. But sure, it’s possible that we’re at the end of the era of human space flight. Just as it’s logically possible that when two billiard balls strike each other at whatever speeds and from whatever angles that they should stop entirely. We only know that’s not true because of our observations of how billiard balls behave in the real world.

In essence, Gott is asking the wrong question. He’s asking: “What reason do I have for believing that we are at the start, rather than the end, of human space flight, and is that reason consistently defensible?” In a post-Enlightenment world, the correct question to be asking is: “Where’s the evidence that we’re at the end of human space flight?” Personally, I see tons of evidence that we’re at the beginning, but none at all that we’re at the end. Therefore the only reasonable conclusion that I can make is that we as a species still have a bright future in space.

UPDATE: I strongly encourage you to read the Centauri Dreams post linked above. My post focuses only on a very narrow part of it, and there is much more to Gott’s argument and Gilster’s commentary than I address here.

1 This argument is isomorphic to the one presented in response to anti-evolution types who falsely invoke the Second Law of Thermodynamics. Entropy must increase on a cosmic scale and in any closed system, true. But our planet is not the cosmos, nor is it a closed system. It’s just a part of the whole. The system obeys the law and so we, at least for a little while, can get a pass and the law still holds.