The Fermi Paradox - Are We Alone in the Universe

[Conservomax]

Fermi's Paradox

Fermi's Paradox (i.e. Where are They?):

The story goes that, one day back on the 1940's, a group of atomic scientists, including the famous Enrico Fermi, were sitting around talking, when the subject turned to extraterrestrial life. Fermi is supposed to have then asked, "So? Where is everybody?" What he meant was: If there are all these billions of planets in the universe that are capable of supporting life, and millions of intelligent species out there, then how come none has visited earth? This has come to be known as The Fermi Paradox.

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 a few million years, every star system could be brought under the wing of empire. A few 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?"

Also, if one considers the amount of time the Galaxy has been around (over 10 billion years) and the speed of technological advancement in our own culture, then a more relevant point is where are all the super-advanced alien civilizations. Russian astrophysicist Nikolai Kardashev proposed a useful scheme to classify advanced civilizations, he argues that ET would posses one of three levels of technology. A Type I civilization is similar to our own, one that uses the energy resources of a planet. A Type II civilization would use the energy resources of a star, such as a Dyson sphere. A Type III civilization would employ the energy resources of an entire galaxy. A Type III civilization would be easy to detect, even at vast distances.

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 extraterrestrial 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.

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Bracewell-Von Neumann Probes:

While interstellar distances are vast, perhaps to vast to be conquered by living creatures with finite lifetimes, it should be possible for an advanced civilization to construct self-reproducing, autonomous robots to colonize the Galaxy. The idea of self-reproducing automaton was proposed by mathematician John von Neumann in the 1950's. The idea is that a device could 1) perform tasks in the real world and 2) make copies of itself (like bacteria). The fastest, and cheapest, way to explore and learn about the Galaxy is to construct Bracewell-von Neumann probes. A Bracewell-von Neumann probe is simply a payload that is a self-reproducing automaton with an intelligent program (AI) and plans to build more of itself.

Attached to a basic propulsion system, such as a Bussard RamJet (shown above), such a probe could travel between the stars at a very slow pace. When it reaches a target system, it finds suitable material (like asteroids) and makes copies of itself. Growth of the number of probes would occur exponentially and the Galaxy could be explored in 4 million years. While this time span seems long compared to the age of human civilization, remember the Galaxy is over 10 billion years old and any past extraterrestrial civilization could have explored the Galaxy 250 times over.

Thus, the question arises, if it so easy to build Bracewell-Von Neumann probes, and they has been so much time in the past, where are the aliens or at least evidence of their past explorations (old probes). So Fermi Paradox becomes not only where are They, but why can we not hear Them and where are their Bracewell-von Neumann probes?

Possible solutions to Fermi's Paradox fall in the following categories:

• They Are Here
  • They Were Here and They Left Evidence
    • UFO's, Ancient Astronauts, Alien Artifacts: all fall under the heading of proposals that aliens are here now (and they call themselves Republicans) or have been here in the recent past. Problem: evidence for aliens is non-existent.
  • They Are Us
    • Humans are the descendents of ancient alien civilizations. Problem: where are the original aliens? Where are all the other alien civilizations
  • Zoo/Interdict Scenario
    • The aliens are here, and they are keeping us in a well designed zoo (cut off from all contact) or there is an interdiction treaty to prevent contact with young races (us). Problem: scenario lacks the ability to be tested. Takes only one ET to break embargo.

• They Exist But Have Not Yet Communicated
  • They Have Not Had Time To Reach Us
    • Speed of light slows communication levels, relativity makes space travel long. ET's message may not have reached us yet. Problem: Galaxy has been around for billions of years, even if one ET civilization formed a few million years before us, the Galaxy would be filled with Bracewell-von Neumann probes.
  • They Are Signaling, But We Do Not Know How To Listen
    • EM radiation, gravity waves, exotic particles are all examples of methods to signal. Problem: they may use methods we have not learned yet, but if there are many civilizations someone would use EM methods.
  • Berserkers
    • The Galaxy is filled with killer robots looking for signals. ET is keeping low. Problem: where are the berserkers coming after us?
  • They Have No Desire To Communicate
    • ET has no interest in conversing with lesser beings. Problem: with millions of possible civilizations, someone would have some curiosity.
  • They Develop Different Mathematics
    • Mathematics is the universal language. But humankind may have a unique system of mathematics that ET cannot understand. Problem: then where are their incomprehensible signals?
  • Catastrophes
    • Civilizations only have a limited lifetime, They are all dead.
      • Overpopulation
      • Nanobots -> Gray Goo Problem
      • Dangerous Particle Physics

• They Do Not Exist
  • We are the First, Life is New to the Galaxy
    • Life is new to the Galaxy, evolution takes time, we are the first civilization. Problem: Sun is average star, if other stars formed a million years ahead of us, then They would be a million years ahead of us in technology.
    

  • Planets With the Right Conditions are Rare
    • Planetary systems are rare
    • Habitable zones, proper distance from star for liquid water, are narrow
    • Galaxy is a dangerous place (gamma-ray bursters, asteroid impacts, etc)
    • Earth/Moon system is unique (large tides needed for molecular evolution)
  • Life Is Rare
    • Life's Genesis is rare
    • Intelligence/Tool-Making is rare
    • Language is unique to humans
    • Technology/Science is not inevitable

In general, solutions to Fermi's paradox come down to either 1) life is difficult to start and evolve (either hard for the process or hard to find the right conditions) or 2) advanced civilizations destroy themselves on short timescales. In other words, this is an important problem to solve in the hope that it is 1 and not 2.

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[Conservomax]

Wasn't the original idea to deconstruct the planet Jupiter? There are several types of Dyson spheres, i believe the one you are thinking of is a Dyson Shell. Which is fundementally impossible to build.

[longshadow]

****Are you really a radioastronomer?****

I have worked in that field, .....
===============================================

And I always assumed you just played one on television.....

;-)

[Consort]

I don't think it has anything to do with distance, speed, time, mass, etc. Those things have to do with the physical universe, which is only one aspect of our being and are just some of the end products or by-products of what we really do, whatever that is.

[William Terrell]

Well, everybody knows that the aliens won't turn their clocking devices and contact us until we have a global government. Then, they will be able to plug values into the N equation, which equation is, to date, the stupidest attempt at mathematical description known.

[edsheppa]

I was just making a point. Obviously it'd be done in a series of shorter trips.

[only1percent]

I've always interpreted the Fermi Paradox as a suggestion of a high likelihood that intelligent life was very rare. Although it doesn't really argue FOR anything, it is thus a good argument AGAINST assuming high values to Drake Equation varaibles.

If reformulated as a hypothesis, though, the Fermi Paradox is quite analagous to the Drake Equation -- a product of numerous small variables, including the underlying likelihood of intelligent life, the likeliness of a species desiring wholesale intergalactic exploration, the feasibility of survivable self-replicating or easily replicated exploring craft, etc. etc.

Although I'm always a bit reluctant to import science fiction thinking, I do think that a moral/ethical component in advanced civilizations may be the best rebuttal of the Fermi Paradox. I suspect that self-replicating probes would never pass ethical muster, due to their destructive potential, and anthropological non-intervention principals would be likely to triumph as well. The development of sophisticated ethical systems seems fairly necessary for a society to reach high technological sophistication; a species gets intelligent only through intense competition, and it survives its advance through fission and fusion only when it can learn to add cooperation and tolerance to competition, the balance of the three forming the base of the advanced ethical system.

[Doc On The Bay]

Agree.

What Fun!!

Let us HOPE that we can manage to Communicate with "Whoever's Out There," 'cause we could Learn SO MUCH!

For a LOT of "Philosophical/Biological/Sociological" Reasons,--WE NEED an "External Intelligence!"

We NEED to disrupt the "Arrogance of" our "Uniqueness!"

Doc

[RightWingNilla]

The earth is like Tatooine.

Yeah but you can still go down to Toshi's station to pick up some power converters.

[PatrickHenry]

P L A C E M A R K E R

[xp38]

Yes but only if you ask in a non whiny voice.

[chickens]

The development of sophisticated ethical systems seems fairly necessary for a society to reach high technological sophistication; a species gets intelligent only through intense competition, and it survives its advance through fission and fusion only when it can learn to add cooperation and tolerance to competition, the balance of the three forming the base of the advanced ethical system.

Eggs Ackley. So, when Fermi asked, Where are they, not everyone raised their hands (antenni) at once. These beings may well walk among us, as some have pointed out, Democrats. When confronted, they won't admit they're from outer space. Just try to get a cat to admit to being from outer space. They never will. But you know they are. And what about that shop teacher in Junior High. You know he was. Betty Crocker and Uncle Ben, both of them were. Nobody knows where these people came from, or where they went. Harley Earl, he's designing Wentlers on Saturn. Dick Nixon, he's got a low level cabinet post on Jupiter. Take a close look at Leon Panetta. They're out there.

[dennisw]

And what nebula is Cokie Roberts from?

[hummingbird]

Fermi is supposed to have then asked, "So? Where is everybody?"

They are next door and from the sound of things, having a pretty good time.

[Las Vegas Dave]

FYI pings.

[Captain Beyond]

bump

[Quix]

THANKS.

[chickens]

Cokie Roberts, exactly. Rumor has it, Starsky and Hutch pick her up, then they pick up Bill Clinton, and the four of them drive around Norfolk Virginia shouting and yelling and throwing beer cans at passers-by. They've been doing this since they were teenagers.

Remember the lead guitar player for Iron Butterfly? He had refused to check in, and was about to give away trade secrets, when they came and got him. Jimmy Hoffa, same thing. Is there intelligent life in the universe? The answer is yes; but at an undisclosed location.

[Virginia-American]

If you consider life on earth from the bacteria through humans, the odds against intelligent life developing, even on a hospitable planet like ours, is in excess of a billion to one.

The way I look at it, life has been on the Earth for about 4 billion (4x 10⁹) years, intelligent life about (say) 100,000 (10⁵), and radio-using life about 100 (10²).

So the odds against intelligence would seem to be 40,000 (4x10⁴) to 1, and against radio-using intelligence about 40,000,000 to 1. Not quite a billion, but...

[chickens]

So, technically, what you're saying is, the smartest people alive in the world, know full well the value of life -- and don't wonder where everybody is (in the universe). They already know where everybody is, so they buy real estate in gated communities and move in next door to them. In other words, this is it. Try to get a room with a view, no corner lots, because the chances of this ever happening again ... well.

[PatrickHenry]

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