Posted on 10/25/2001 9:13:53 AM PDT by RightWhale
Is there obvious proof that we could be alone in the Galaxy? Enrico Fermi thought so -- and he was a pretty smart guy. Might he have been right?
It's been a hundred years since Fermi, an icon of physics, was born (and nearly a half-century since he died). He's best remembered for building a working atomic reactor in a squash court. But in 1950, Fermi made a seemingly innocuous lunchtime remark that has caught and held the attention of every SETI researcher since. (How many luncheon quips have you made with similar consequence?)
The remark came while Fermi was discussing with his mealtime mates the possibility that many sophisticated societies populate the Galaxy. They thought it reasonable to assume that we have a lot of cosmic company. But somewhere between one sentence and the next, Fermi's supple brain realized that if this was true, it implied something profound. If there are really a lot of alien societies, then some of them might have spread out.
Fermi realized that any civilization with a modest amount of rocket technology and an immodest amount of imperial incentive could rapidly colonize the entire Galaxy. Within ten million years, every star system could be brought under the wing of empire. Ten million years may sound long, but in fact it's quite short compared with the age of the Galaxy, which is roughly ten thousand million years. Colonization of the Milky Way should be a quick exercise.
So what Fermi immediately realized was that the aliens have had more than enough time to pepper the Galaxy with their presence. But looking around, he didn't see any clear indication that they're out and about. This prompted Fermi to ask what was (to him) an obvious question: "where is everybody?"
This sounds a bit silly at first. The fact that aliens don't seem to be walking our planet apparently implies that there are no extraterrestrials anywhere among the vast tracts of the Galaxy. Many researchers consider this to be a radical conclusion to draw from such a simple observation. Surely there is a straightforward explanation for what has become known as the Fermi Paradox. There must be some way to account for our apparent loneliness in a galaxy that we assume is filled with other clever beings.
A lot of folks have given this thought. The first thing they note is that the Fermi Paradox is a remarkably strong argument. You can quibble about the speed of alien spacecraft, and whether they can move at 1 percent of the speed of light or 10 percent of the speed of light. It doesn't matter. You can argue about how long it would take for a new star colony to spawn colonies of its own. It still doesn't matter. Any halfway reasonable assumption about how fast colonization could take place still ends up with time scales that are profoundly shorter than the age of the Galaxy. It's like having a heated discussion about whether Spanish ships of the 16th century could heave along at two knots or twenty. Either way they could speedily colonize the Americas.
Consequently, scientists in and out of the SETI community have conjured up other arguments to deal with the conflict between the idea that aliens should be everywhere and our failure (so far) to find them. In the 1980s, dozens of papers were published to address the Fermi Paradox. They considered technical and sociological arguments for why the aliens weren't hanging out nearby. Some even insisted that there was no paradox at all: the reason we don't see evidence of extraterrestrials is because there aren't any.
In our next column, we'll delve into some of the more ingenious musings of those who have tried to understand whether, apart from science fiction, galactic empires could really exist, and what implications this may have for SETI.
Yeah, whatever. No sane person with even a rudimentary knowledge of physics, much less an expert, could possibly believe something this preposterous.
So you're suggesting that Fermi was either insane or lacked even a rudimentary knowledge of physic? How very interesting!
I think you need to go back and read the original article.
If life has never existed, then truly we are unique in this universe and whether it be earth or someplace else there had to be or is a first life.
Again given the time and size factors, where are they, the odds are in favor of life being out there.
Personally, I've always like the answer, "look in the mirror." "They" may have indeed already colonized the galaxy. Problem is, they had to do it as dormant bacteria hitching rides on asteroids and other celestial debris.
Multiple SETI searches have been going on, what, twenty or thirty years now? That's an impressive statistical sample and I think we can begin to draw some valid statistical inferences from the data; namely, technologically we're IT in the Milky Way (small p, perhaps even p<0.05).
Thank God! I don't think I want us encountering a vastly more advanced civilization.
Radical Islam got to them.
Or you can insert your own favorite villain in the blank.
Maybe the Alpha Centaurian Lew Rockwell and the Alpha Centaurian Jonah Goldberg's mother got nuclear weapons and destroyed that flourishing civilization. Maybe television radiation turned all of the Vulcans into vegetables or zombies.
We are.
It's possible. But it doesn't solve the problem.
Not in any way that's relevant to travelling from point A to point B. No violation of Einstein's relativity has ever been observed. Popular articles about light pulses travelling faster than c stem from a confusion about the difference between group velocity and phase velocity.
These would be problems to us, but not necessarily to all cultures. All that would be needed for a galactic empire would be one race willing to put up with these difficulties and enough time. As Fermi points out, time isn't a problem. Were there enough spacefaring races, then at least one of them would have had the patience to build an empire by now.
On a side note, sci-fi author Harry Turtledove addressed the issue of patience in his "Worldwar" series. In those books, the Earth is invaded by "The Race" during WWII. The Race has been a spacefaring people for thousands of years. Their plans to invade Earth evolved over centuries. They sent a probe to Earth that arrived 600 years earlier. They were so confident that all races shared their patience for slow development that they expected to find nothing more than mounted knights opposing their invasion force; not modern armies able to fight them to a standstill. One of the major themes of the books is the Race's inability to grasp how impatient we are as a species and how this drives our technological development. The Humans, on the other hand, learn patience from the invaders and have begun to plot a counterattack on the Race's homeworld, Tau Ceti.
No, but if they can only move at a hundredth of a percent of the speed of light--a much more reasonable figure--then it does matter. The fact is, going from star to star is just plain hard. I fully expect that corporeal human beings will never make the trip. (Once we learn how to transfer our consciousness to nonliving substrates, however, we just might manage it.)
Please pass me some info on this. Thanks
Scotty
No way can you draw that inference from the SETI data. It's not a question of statistics, it's a question of sensitivity and of coverage. If there were a carbon copy of Earth out there, you wouldn't have to move it very far away before we're highly unlikely to have seen it. We're not close to having looked at our own galaxy exhaustively.
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