Our Galaxy Should Be Teeming With Civilizations, But Where Are They?

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.

If you take into account all the known various factors that make life possible on earth, it can be shown statistically in ALL the universe there is almost no chance of another planet capable of supporting life... see The Improbable Design of Our Earth and Solar System.

I love Star Trek too, but facts are facts--and other than God and the spiritual world--we likely are alone in the universe.

Can we in principle make devices that, individually, think like we do, and remember what we remember?

Absolutely. There is nothing impossible about it; we are just limited by current technology, not by current theory. But for some arguments (and some people), the "copy" issue is a big deal. Not that it is particularly relevant here. :^)

Rare Earth: Why Complex Life is Uncommon in the Universe

"Do you feel lucky? Well do ya?" asked Dirty Harry. Paleontologist Peter Ward and astronomer Donald Brownlee think all of us should feel lucky. Their rare Earth hypothesis predicts that while simple, microbial life will be very widespread in the universe, complex animal or plant life will be extremely rare. Ward and Brownlee admit that "It is very difficult to do statistics with an N of 1. But in our defense, we have staked out a position rarely articulated but increasingly accepted by many astrobiologists."

I'm still trying to figure out what happened to the Incas and the Aztecs.

Spaniards.

That response ia a triumph of ignorance and ideology over reality.

No, it is a humorous one word answer, and truthfull as far as it goes. It isn't a treatise. Lighten up guy.

Fermi's point is that we don't need to look. They would be here.

That's a theory based on logical conjecture. It makes sense in some ways but it just takes one life-bearing planet to demolish the theory. I prefer empirical data to theoretical data. In the 2010 time frame we should have the instruments we need to test this theory. (Terrestrial Planet Finder etc.)

Perhaps we are merely quarantined. Perhaps the rest of the universe does consist of life that is eternal, but because of the lack of our moral development, we cannot share in the technological treasures that have been developed in the millions of years the universe has had to evolve. Perhaps even occasionally the universe sends us a representative that demonstrates His powers and their hopes for us, and we crucify Him for that love. Perhaps with an act of will we can even download an antivirus that slowly begins to transform us into a being capable of living with the rest of the universe. Who knows what amazing technologies might exist with millions of years of development beyond our own?

linkages to a central authority would be next to impossible.

Well if that is the case it is obvious that it would be illegal, anything in society that is outside the scrutiny of a central authority is always forbidden. Hence, no aliens.

I have read similar articles on Fermi's insights on this before. It does have the clarity of logic behind it. One thing that he does not consider though is the possibility that highly advanced civilizations with technology that we cannot possibly comprehend may not be the type of civilizations to mindlessly expand to other solar systems just for the sake of expansion. In other words, they are beyond that type of physical conquest. Also, a highly advanced civilization might act as a protector for emerging civilizations, such as ours, from the more hostile galactic regimes. It is noteworthy that we here in America have long ago gave up our conquering ways (not to be confused with wars to protect our interests) and replaced it with friendly collaboration and alliances.

Finding life really isn't enough. As most people educated in the relevant sciences will tell you, the hardest step wasn't going from chemicals to simple cells, but from going prokaryotic cells to eukaryotic cells. It isn't the part that most people look at, but it IS the important step that allowed the rest to happen, and it still has people scratching their heads today. There are lots of theories, but that step is considered to be the most improbable in the entire sequence of events.

I'm still trying to figure out what happened to the Incas and the Aztecs. Seems like I keep hearing about archeologists who dig up these highly complex civilizations that somehow just whithered away.

Bad religion.

Fermi's point is that we don't need to look. They would be here. Agree or disagree, but that is the argument. There are a lot fewer unknown variables in Fermi's conjecture than in the Drake equation.

Hog wash! Its a long way to even the nearest star and how would they know we were even here to begin with. What I see is many little islands (solar systems) that are completely isolated by distance and General Relativity.

There were other civilizations. But one-by-one, their liberals destroyed them.

Liberalism is indeed our seeds of destruction. I guess there could be an alien strain of this too!

That's a pretty good statistical start, at least when it comes to saying something about the prevalence of advanced civilizations in the galaxy.

We haven't even scratched the surface towards a comprehensive search. Which frequency, where, what sensitivity, what polarization, etc. My search is looking strait down our spiral arm. The most bang for the buck per say. But even when I finish my upgrade, I will still be only scanning 30 million frequencies. A tiny drop in the bucket.

One thing that he does not consider though is the possibility that highly advanced civilizations with technology that we cannot possibly comprehend may not be the type of civilizations to mindlessly expand to other solar systems just for the sake of expansion.

People after Fermi have spent a great deal of time on this very issue. For a number of reasons that I won't go into here, it turns out that one can demonstrate that grabbing resources as fast as you can is critical to survival in the long run and that any highly developed and rational society would HAVE to expand outward at a very fast pace. The calculus of it all points to advanced civilizations dismantling natural resources at a dizzying pace. The rational solution when the number of civilizations is one is very different from the rational solution when there are many civilizations.

I don't think we will "transfer" our consciousness to anything else. I think that's impossible.

Do you really think it's impossible in principle, or just prohibitively difficult (as I believe interstellar travel to be)?

I think it is impossible in principle. That is, the idea that you could wake up in some machine body after undergoing a transfer procedure is impossible. We will build machines that are just as intellectually capable and "alive" as ourselves, but they will be their own selves.

The think our minds are constructs of our brains and although we might be able to build machines as capable we can't move into them unless we can put our brains in them and keep them alive. Even if we could somehow download the information content of our brains to a machine, that machine would be a copy. It wouldn't be me any more than my clone is me.

We haven't even scratched the surface towards a comprehensive search. Which frequency, where, what sensitivity, what polarization, etc.

There is also the problem of efficiently transmitted signals being essentially indistinguishable from noise. It took human civilization an extraordinarily short amount of time from the first usable radio transmissions to extremely efficient transmission coding (which is just starting to become common here). It is improbable that SETI will trip over that narrow window, when the practical civilization window is millions and billions of years. It doesn't help to be able to receive a signal if you can't tell that it IS signal.

We're not only living in a rural area, but in a rural area that has been stripped of a lot of natural resources such as interstellar gas of various kinds.

This kind of galactic environment might be one of the conditions necessary to spawn life. It spawned us. The interior of the Milky Way may be just too active and hot of a place to be conductive to life.

Hogwash if you like, but over tens of millions of years, any intelligent beings are going to try to span the distances. You really have a billion years or so to work with.

I'm note sure that is the case. The universe is approximately 14 billion years old and the heavier elements were formed in supernovae. So for planets and life to arise, it had to be in the second or third stellar generations. Intelligence also took 4 billion years to come to fruition on this planet, why not others. We all may be emerging about the same time. Some sooner others later, but the history of the human race is such a tiny time compared to the time life has been on this planet.

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.