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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[parsifal]

Yes, it is I. I have been on sabbatical studying the metabolic changes in starving chickens. Apparently, if less food is provided than what it takes to stay alive, most chicken opt to die. ABTW, I solved the chicken problem. Its just that few at FR recognized me as the practical economics genius that I am. parsy the reclusive.

[Mitchell]

Bump.

[parsifal]

What if we just couldn't see stuff that far away because the light petered out. parsy, who is not doubting your expertise, but who is hard to convince.

[Doctor Stochastic]

Go to the Milky Way? The Three Musketeers can't even afford to go to Mars.

[beaver fever]

I you had the choice of visiting Watsonville CA or staying home what would you do?

An alien monitoring the cultural and technological development on planet Watsonville would probably decide the trip wasn't worth the time and resources required. A visit to planet Watsonville may even be dangerous.

So what about accidental visits to Watsonville?

In 1980 I accidentally landed on this strange planet on my way to an even stranger world called San Francisco. I rented a motel room from a suspicious and well armed night clerk. The shower in my room was covered from floor to ceiling with a greyish green fungus half an inch thick. I guessed that local food stuffs were similarly infected and chose to consume only those provisions I brought with me. The next day I left the planet, taking great pains to avoid any further contact with native species both plant and animal. Since the encounter I have not returned to Watsonville and studiously avoid all exits off I-90 even for precious fuel.

In short the Fermi Paradox is false. It is not at all paradoxical that an alien civilization from another planet with sufficient technology and knowledge of Earth would chose not to contact us. The truth is we probably scare the crap out of them.

[general_re]

It must be painful not to have your talent recognized for what it is ;)

[Doctor Stochastic]

The aliens did leave a book called "How to Serve Humanity."

The good news is that it's not a cookbook.

The bad news is that is a tennis instruction manual.

[RightWhale]

Even the moon, which is so close some nights you could reach out and touch it, is beyond the capability of the Chinese now, and NASA is in no hurry, either. Strange that 30 years ago we thought reaching the moon was no big deal. Looks like it won't be us warrior nomads overrunning the Milky Way.

[Fitzcarraldo]

Perhaps the Voyager spacecraft should be on the lookout for robotic game wardens that are programmed to destroy any thing leaving our solar system ;^).

[xrp]

If something happened to be living here 100,000 years ago and didn't happen to build megalithic structures, it would all be gone back to nature. If we found some fossil bones, we might not recognize them as alien, especially if they were related to us in the first place.

Yet there are fossilized footprints (dinosaurs) and other evidence of life from the past...hmmmm

Then there are these 3 interesting claims:

A 75-foot trail of human footprints have been found in Tanzania in a layer of volcanic ash, which was dated at 3.75 million years old. T. D. White in describing the footprints said, "Make no mistake about it…they are like modern human footprints. If one were left in the sand of a California beach today, and a four-year old were asked what it was, he would instantly say that somebody had walked there. He wouldn't be able to tell it from a hundred other prints on the beach, nor would you." (D. Johanson and M. A. Edey, Lucy the Beginnings of Humankind, Simon and Schuster, New York, 1981, p. 250, as sited in Evolution: The Challenge of the Fossil Record by Duane T. Gish).

Human footprints and been found in the same strata as dinosaur prints in the Paluxy River Bed in Glen Rose, Texas. The prints are within a few yards of each other, and sometimes even cross each other. Dr. Camp from the University of California and Dr. G. Westcott of Ypsilanti, Michigan have pronounced them genuine. The human footprints continue under shale that has been bulldozed away, proving they could not have been carved in the formation. (Winkie Pratney, Creation or Evolution? The Fossil Record, Pretty Good Printing, 1982).

Two fossilized human skeletons have been found in Cretaceous sandstone at Moab, Utah. The fossils were found in strata supposedly 65-100 million years before humans were said to have evolved. (Burdick, C.L., "Discovery of human skeletons in Cretaceous Formation", Creation Research Society Quarterly, vol. 10, no. 2, September 1973, pp. 109-110.)

If you believe the evolutionary path of humanity (which I don't) we certainly shouldn't have human footprints 4,000,000+ years old that are virtually identical to human footprints of today.

[samtheman]

All planets follow the same pattern: First there's life, then there's life abundantly, then there's intelligent life, then there's Islam, then there's mass murder, mass suicide, destruction of civilization, and intelligent-species extinction.

(Just a thought.)

[Gorjus]

I think you're wrong. Are you sure you have all the variables accounted for? How about you list them, just to be sure?

Um, did you actually read my posting?

First off, the point of my posting is that there may very well be additional factors - such as the need for the planet to support a very stubborn life form like a 'cursorial hunter.' So I never claimed to account for all the variables - just the opposite. I introduced a new one, or at least, a new aspect that influences one of the standard factors. (Specifically, fc - the probability that a civilization develops technologically.)

Second, you might actually want to read the article as well. Essentially at the end of the article - just above the last illustration - the article provides exactly what you're looking for in the N=N*f... equation. At least, it lists those variables which are commonly considered to address the problem. The point of my posting - taken from that long-ago article in Analog - was that developing a technological civilization may require that a particular evolutionary niche be supported. As such a factor that might be reasonably small - say, 1 in a thousand chance that an intelligent life develops a technological civilization - might actually be more like 1 in a million due to the combined requirement not only to have an intelligent life that develops a technological civilization, but that the intelligence be very stubborn as well.

You don't have to agree. But you really should read a little more carefully before you disagree.

[RightWhale]

Fortean data keeps one's mind from fossilizing.

[Fitzcarraldo]

God created atomic numbers over 90 to limit intelligent life forms to one planet.

[RightWhale]

Fermi's paradox induces aphorisms.

[RadioAstronomer]

You guys are arguing the Drake Equation as apposed to the Fermi Paradox.

[PatrickHenry]

Human footprints and been found in the same strata as dinosaur prints in the Paluxy River Bed in Glen Rose, Texas. The prints are within a few yards of each other, and sometimes even cross each other. Dr. Camp from the University of California and Dr. G. Westcott of Ypsilanti, Michigan have pronounced them genuine. The human footprints continue under shale that has been bulldozed away, proving they could not have been carved in the formation. (Winkie Pratney, Creation or Evolution? The Fossil Record, Pretty Good Printing, 1982).

Your source is almost a quarter-century old. This stuff was debunked long ago, and now survives only on creationist websites: Paluxy River claim debunked.

Two fossilized human skeletons have been found in Cretaceous sandstone at Moab, Utah. The fossils were found in strata supposedly 65-100 million years before humans were said to have evolved. (Burdick, C.L., "Discovery of human skeletons in Cretaceous Formation", Creation Research Society Quarterly, vol. 10, no. 2, September 1973, pp. 109-110.)

Also debunked: Moab, Utah skeletons.

Hint: to achieve any credibility in a science thread, your claims must be sourced somewhere other than a creationist publication or website. They are notoriously unreliable.

[xrp]

OK thanks.

[xp38]

It's all very simple. The earth is like Tatooine. It exists on the outer rim and the Empire has little interest or influence in this system.

[Physicist]

"Petered out", how?