Posted on 11/08/2001 7:52:53 AM PST by MeekOneGOP
Thursday November 08 09:37 AM EST
This puzzle, known as the Fermi Paradox, has burned up a lot of cerebrum cycles when scientists tried to reconcile the lack of company with the expectation that there are many advanced alien societies.
One possible explanation is that interstellar travel is just too costly. Consider how expensive it would be for us to populate another star system. Imagine sending a small rocket to Alpha Centauri, one that’s the size of the Mayflower (180 tons, with 102 pilgrims on board). Your intention is to get this modest interstellar ark to our nearest stellar neighbor in 50 years, which requires about 150 billion billion joules of energy.
No one’s sure what aliens pay for energy, but here on Earth the going rate is about ten cents a kilowatt-hour. So the transportation bill per pilgrim would be $40 billion. That’s a lot of moolah, a lot more than it takes to buy each emigrant a few thousand six-bedroom palaces and set him up for life. The fact that the trip is costly, in whatever currency, is reason enough to deter any alien society from trying to settle distant real estate. With far less expenditure, the extraterrestrials could pursue the good life at home.
Of course, if energy costs can be brought way down, for example with fusion or matter-antimatter technology, or by capturing more of the radiation spewed into space by the home star, this explanation might not hold water.
But even if the aliens can afford colonization, maybe they haven’t got the stamina to see it through. Subduing the Galaxy takes more than sending a ship full of restless nomads to the next star. The nomads have to settle that star, and then spawn pilgrims of their own. And those émigrés have to produce yet more settlers. And so on. If each and every colony eventually founds two daughter settlements (a pretty decent accomplishment), then 38 generations of colonists are required to bring the entire Galaxy under control. Even the Polynesians, who swept across the western Pacific domesticating one island after another, didn’t manage this. Maybe the aliens can’t do it either.
On the other hand, if a few of them remain committed to expansion, their project might still succeed – just more slowly.
Some researchers suggest that the Galaxy is colonized, but we just don’t notice. Arthur C. Clarke pointed out that truly advanced engineering projects would be indistinguishable from magic. Perhaps the evidence of alien presence is so beyond us that we simply don’t recognize it (somewhat like mice in The Louvre checking out the Mona Lisa). Another thought is that the aliens find Earth an interesting nature park, and have arranged matters so that, while they can observe us, we can’t observe them. The idea that we may be some aliens’ high-tech ecological exhibit is called the "zoo hypothesis."
These explanations, and a bushel-basket more, have been proffered to deal with the Fermi Paradox. Any of them might be true. Nonetheless, some scientists find them too contrived, too unlikely to work in every case. Will all the aliens find colonization too costly? Will they all run out of empirical steam? Are we so special that someone has really gone to the trouble to put us behind invisible bars?
Or is there a much simpler explanation?
Next time, we’ll consider some of the more obvious – if more disquieting – resolutions of the Fermi Paradox.
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Let's check this. The mass of 180 tons is 180,000 kilograms. The velocity given is 8% of the speed of light, and the speed of light is 3x108 m/s. Kinetic energy is 1/2 m v2, but we can double the energy expenditure because of deceleration. So the total energy, in joules, is 6.4x10-3 times 9x1016 times 1.8x105 = 1.04x1020, or about 100 billion billion joules. Close enough.
The problem is that the fuel and propellant required to decelerate that mass is gigantically large compared to 180 tons. But that mass must also be accelerated to that speed (and for the most part, decelerated). So that requires an amount of fuel and propellant that is again gigantically large compared to the fuel and propellant I already named. These aren't part of the author's energy budget.
Then there's the question of whether 180 tons of stuff can keep 102 people alive for 50 years. If the Mayflower took that long to cross the ocean, it wouldn't have bothered setting out. It's not just an expensive proposition; the equations don't admit of a solution.
There are actually more assumptions in the "alone in the galaxy" arguement than in the "there's somebody else out there" position.
Yup. Here's a theory for you: any sufficiently advanced civilization will eventually spawn liberal infestations, who will likely succeed in dragging the civilization back down the ladder of progress. :)
Occam's Barber shop--two chairs, no waiting!
Typical human response. Who is to say that if "life/civilizations" existed elsewhere that they would know of or have an economic or monetary system.
Even here on earth we have many examples of "civilizations" existing and functioning without money or other economic concepts.....bees, ants etc. These creatures exist and accomplish everything necessary to fulfill their lives without an ATM machine. How refreshing.
(a) It costs too much and the money would better be spent on shopping carts for the homeless; and
(b) It's just too dangerous. Someone might get hurt.
The problem of building a closed ecology is tough, but not insoluble in principle (though it probably would require rather more than a ton and a half of mass per person). Once that problem is solved, accelerating an "interstellar ark" to a speed that will get it to a nearby star before something critical gives out (i.e. a few percent of c) is also tough but not insoluble.
My favorite solution to the Fermi Paradox is the theory that, life inside the closed ecology becomes the "new normalcy" and that arks arriving at a new system just aren't all that interested in it except as a subject of scientific study and a source of raw materials (for the latter, asteroids and comets are easier than planets, if you're out in space to begin with). Thus, systems get visited but not colonized (at most, there would be the occasional long stop to build new arks when the old one gets too crowded or worn out).
We are it, there aren't any other advanced life forms. I suspect alien algae is our most highly developed universal neighbor.
It didn't take us long. About 8000 years from the end of the last ice age to the present -- more than half of which is recorded in written history.
An a species only has to do this once. The colonists will have their past to build on.
If we assume that colonization proceeds at small fraction of the speed of light, the technological advances made by the home planet will always be available through ordinary radio transmission.
So even if the colonists hibernate during travel, they will wake up to knowledge that advanced while they were asleep.
My remark was referencing other civilizations in our or other galaxies. Who is to say that the concept of cost exists elsewhere if other civilizations exist?
The mechanics and logistics of space travel are very daunting. It's a VERY long way to the next place and we may not be able to get there from here. There's no Denny's on the way.
My "touchy feely" new age friends do not want to hear this. Many people want to, need to believe in the magic or other powers or something else other than the absolute banality and mundane ness of their lives and life on our pretty little planet. If there is no one else in the universe, it means we have to take total responsibility for our lives and all our decisions and actions on the planet. There's no one else or thing to blame anything on. It's much easier for some when they have an out. Victim hood is easier. Many are afraid that this is it. Short, sweet and a one way trip.
There are a few articles in the Arts & Letters Daily web site that may relate to some of this, they are :http://www.prospect-magazine.co.uk/ArticleView.asp?Accessible=yes&P_Article=7269 and : http://www.nybooks.com/articles/14796
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