** ADDENDUM: 2010.10.05: Okay, everything is now illuminated: As my reader Richard Leis, Jr. points out, "The discovery of Gliese 581 c was announced in 2007. Last week's announcement was Gliese 581 g. C was initially considered a good candidate for potential life, but later calculations suggested it was actually outside the star's habitable zone. G is considered a better candidate because calculations place it more firmly within the habitable zone." **
Well, whatever. What's important to note is that (1) it reaffirms the notion that we (likely) live in a biophilic Universe and (2) its presence deepens the disturbing nature of the Fermi Paradox. As a potential data point that works to increase the value of n in the Drake Equation, it serves to reinforce the suggestion that, while we find ourselves in a Universe that is likely teeming with life, it's not one that's teeming in space-faring civilizations. Consequently, its discovery is not exactly good news.
Here's what I wrote back in April of 2007 when Gilese 581 was first discovered:
Wow, the blogosphere has been absolutely gushing these past few days over the news that an Earth-like planet may have been discovered in the 'hood. This planet may boast a moderate climate that could conceivably support life and is only 20 light years away.
Not surprisingly, this news has caused a number of pundits to fantasize about jumping into their rocketships and bidding adiós to our polluted, war-torn and diseased planet.
But not so fast, amigos. While many have misguidedly jumped on the bandwagon to the stars, a number of bloggers have gotten it right.
In his article, "'Don't Pack Your Bags Just Yet", Jamais Cascio notes that, "By the time we have the technology that would make a 20 light year trip even remotely plausible (the fastest space craft yet made would still take thousands of years to get there), we probably won't be all that interested in living in a watery gravity hole anyway. Nope -- give us some nice, massive gas giants to convert to computronium!"
Michael Anissimov points out that we have a human hospitable planet right here that we’ve barely even begun to use. He also argues that "even if we did need to leave the Earth, there is a tremendous amount of raw materials for space colonies right next door in the form of carbonaceous asteroids, which make up about 75% of known asteroids." Moreover, warns Anissimov, "we should think carefully before sending off colonists to far-away places without ensuring that they’re capable of protecting the fundamental freedoms of their citizens." Specifically, he worries that a blight may come back to haunt us (which also reminds me of the Honored Matres of the Dune series).
And as Tyler Cowen noted, "Are earth-like planets so common? That probably means lots more civilization-supporting planets than I had expected. But where are the alien visitors? As suggested by the Fermi paradox, we must revise our priors along several margins, one of which is the expected duration of an intelligent civilization."
Indeed, Cowen is on the right track. A primary argument used to reconcile the Fermi Paradox is the Rare Earth Hypothesis. This line of reasoning suggests that we haven't been visited by ETI's because life is far too rare in the cosmos.
But if we have discovered an Earth-like planet as little as 20 light years away, it's not unreasonable to suggest that our Galaxy must be absolutely teeming with life. This would seem to be a heavy blow to the REH.
So why is this bad news? It's bad news because our biophilic universe should be saturated with advanced intelligence by now...but it's not. The Fermi Paradox is very much in effect as a profound and disturbing unsolved mystery in astrosociobiology, philosophy and futurism.
Are all civilizations doomed before getting to the Singularity? Or is there something else at work here?