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Where Have All the Spacemen Gone? Part 2

Posted: Mon Feb 12, 2007 4:19 am
by trurl
Here is Part 2, reposted here from our previous website.

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Where Have All the Spacemen Gone?
Speculations on the Fermi Paradox, Part 2


by Christopher Jones

Original Publication Date: June 7, 2002

Oh, you get me ready in your flying disc, baby. Why don't we go set down on the Earth? Take shelter on the...

Oh, sorry about that, I didn't know you were listening. Looks like it's time to continue our discussion on the Fermi Paradox, so I'd better stop singing.

Last time we met we broke down the Paradox into three general solutions: 1) There is no one out there; 2) There is someone out there, but they have no interest in space travel and contacting others, or they conceal themselves for ethical reasons; and 3) When a civilization reaches a certain level of technological development it destroys itself in a terrible war. We discussed the first possibility in Part 1, and this time we will set out to tackle the second.

This second solution is much more interesting, and though we have singled out lack of interest and concealment, there is really a lot more to it. In all we'll be covering six possibilities, three in this installment and three in the next. In this article we will consider:

1) Space travel is too costly.
2) Lack of interest in exploration.
3) Not enough stamina.

So let's get underway and find out if any of these arguments seem convincing.

BUDGETARY RESTRAINTS
One argument that has been made to explain the absence of signs of galactic colonization is that it is simply too expensive to set out for the stars. Looking at NASA's present-day financial situation -- with the periodic slashes from the Congressional financial dagger -- this scenario is not so far-fetched.

There are many who would love to see us begin colonizing Mars. We have the technology, what we lack is the funding (and the motivation). The politicians who hold the purse strings see no real need to make moves on the Red Planet (preferring to make moves on young interns instead), and thus we are unlikely to set foot there for more than a basic exploratory mission any time soon. And we're only talking about Mars! On galactic terms, this is like stepping next door to ask the neighbor if you can borrow some eggs. This is nothing compared to actually spreading out into the cosmos, which is what the aliens would have to do for us to see them all around and counter Fermi's big question.

Just how much money are we talking about? In an interesting article on the SETI Institute website, SETI Institute Senior Astronomer Seth Shostak points out that, using present day Earth rates for energy -- which are about ten cents per kilowatt-hour -- it would cost us $40 billion dollars per colonist to send a ship of pioneers to Alpha Centauri, which is the nearest star at a distance of roughly four light-years. He also points out that advances in energy production methods could drastically bring down the costs, but it is clear that if an alien civilization faced such financial restraints they might find it too costly to bother with a project to colonize the Milky Way. Result? We find no aliens.

THAT'S LIKE SO BORING, YOU KNOW?
Valley Girl aliens? Nope, just catchy section title; and all to point out that aliens might have no interest in spreading through the galaxy, exploring the stars and planting their flag in the soil of other worlds. Given our history of fervent expansionism and burning desire to know what lies beyond the next hill, this seems hard to swallow. But it is entirely possible that there are cultures out there that evolved in such a way that they lack those explorer qualities that we so associate with ourselves.

This could happen for another reason besides cultural tendency. In his short story "Blood Music," Greg Bear describes the disastrous outcome of a genetic engineering project that results in the human race being taken over by tiny biological machines of our own making. Mankind is transformed into a completely new life form just as it is beginning to gain the ability to expand into space. The new life form is immobile and is interested in exploring the planet through its microscopic messengers. At the end of the story, he asks how many other worlds have fallen victim to the same circumstances. Result? We find no aliens.

I CAN'T TAKE IT ANYMORE!
I had a much more clever title for this section, but decided not to use it; this is a family site, after all. But getting to the point, another possibility that has been proffered is that aliens might set out to colonize the galaxy but decide along the way that it is too much work and give up.

The general idea that appears in a lot of writing about SETI is that any civilization with the means and the inclination could colonize the entire Milky Way in roughly 10 million years -- a blink of an eye on the galactic timescale -- by establishing one colony that a few hundred years later would establish a few of its own, and so forth until all the star systems in the galaxy are occupied.

Again in one of his SETI Institute articles, Seth Shostak offers some figures on just what it would take to build the empire. His timescale differs somewhat from the one just mentioned, but he points out "if each and every colony eventually founds two daughter settlements.... then 38 generations of colonists are required to bring the galaxy under control." That's what I call a long-term project, to say nothing of the hardships that settlers would have to face as they attempt to conquer new lands. It is easy to see how at some point they might decide they'd gone far enough. It could be that this has happened and the territory they did settle is on the other side of the galaxy. Result? We find no aliens.

MOVING ON
So there we have it: three plausible reasons why our search for other life has thus far turned up empty. In the next installment of "Where Have All the Spacemen Gone?" we'll look at three more possibilities:

1) We are being quietly observed.
2) Ethics get in the way.
3) A barrier could prevent our contact with others.

Now, where was I? Oh... Where is my little green man? Where is his shiny gun? Where is my cosmic ranger? Where have all the spacemen gone? Doo doo doo, doo doo doo...

Posted: Mon Feb 12, 2007 2:00 pm
by Windwalker
It's great to have all four parts of this essay in one place, so that it can be read in one fell swoop. The quest for extra-terrestrial life is an endeavor that captures the human imagination very powerfully, especially the possibility of intelligence.