Your Top 3 Fermi Paradox Solutions

[Luminal]

There's no limit to the varying ideas about why the Fermi Paradox occurs, so I think it would be interesting to hear others' ideas.

 

My top 3 list (from most likely descending toward less likely):

 

1) Chemical Evolution, plain and simple. It is so unlikely, even over billions of years, trillions of gallons of water, and millions of suitable planets, that life is extremely rare. Chemical evolution has always been the weakest point in the theory of evolution in my eyes. The odds of any self-replicating molecule coming into existence are inconceivably low. For life of Earth, somehow an information-storing molecule (RNA most likely) had to come into existence through an infinitesimal spurt of fortune, and then have a way to synthesize itself into longer and/or different chains via an early protein of some sort.

 

2) Speed of light unbreakable, even by billion-year-old technological civilizations who have thought of every method possible to attempt to bypass it (and failed). With the sheer size of the Universe, and with no way to go faster than light, they stopped expanding when they realized how long it would take.

 

3) Civilization reaches satisfaction/bliss/utopia/fulfillment, and the pressing need for expansion and/or exploration is sated permanently. For humans, this might be a virtual reality in 100 years or so where we can quite literally live in any time or place, even in fictional worlds, and be anyone or anything we could possibly desire. At this point, why risk your life exploring space, when you can live any experience with the same realism (or more) than the dreary physical world?

[foofighter]

1)Zoo hypothesis

 

maybe i'm just being optimistic, but oh well

[foodchain]

1) There is progress being made in this area. Its a rather profound question, but in all reality the science of the common compact disc has massive amounts of more attention giving to it. One thing about chemistry is reaction mechanism also, such as in geology is quite amazing the natural processes that lead to various chemical compounds. As for all the water on earth, well comparing the mass of the earth to the universe, is it really that much, plus it seems the solar system, or formation of such has lead to some "stratification" if I can speak metaphorically in my opinion.

 

2) Such may not be a large issue to beings that want instant gratification or simply perceive reality differently on either a nature or nurture level overall.

 

3) For one, the universe is massive, another is intelligent life I doubt is some guarantee of life, nor what is exactly the definition of intelligent.

[Reaper]

1) We probably haven't checked enough stars.

 

2) Speed of light barrier. Meaning that if they are spreading out, it would be impossible to establish an empire as portrayed in Star Wars.

 

3) Machine intelligence, though very speculatory at this point.

 

 

Oh, by the way, even if it is truly impossible to get around the light speed barrier, any civilization could theoretically colonize the galaxy in a few million years. Of course, they would be cut off from their home world and so would develop a radically different civilization and evolve independently, both biologically and technologically.

[Martin]

speed of light limit is no problem

you just send robot craft to habitable-looking planets with instructions to plant seeds of life (if nothing growing there already)

 

doesnt matter if it takes the robot 1000 years to get there.

 

no reason our species shouldn't have the honor of extending earth-type life to other habitable planets

if we don't cripple ourselves and our planet first

===============

 

what's the "Fermi paradox?"

I remember hearing a lot about Fermi's QUESTION some thirty years back.

Something like "where are they?"

 

that makes sense, it is a good question. All it does AFAIK is lead to the conclusion that intelligent life with an evolved instinctive drive to extend habitat must probably be either RARE or else LATE APPEARING in the life of a galaxy.

 

Lineweaver has a definition of the habitable zone of a galaxy

1. where secondgeneration metal-rich stars form

2. where it is not too crowded, like in the hub

MAYBE IT TAKES 4 billion years for a lot of habitable planetary systems to start appearing. Maybe the Sol system is one of the earliest generation in the Milky.

Maybe expanding life only really gets rolling about now, like when a galaxy is 8-10 billion old.

 

I don't think there is any paradox

there is only this good question which makes you think. Lineweaver is one of the best cosmologists around---worth reading what he has to say about it

 

Go here

http://arxiv.org/multi?group=grp_physics&%2Ffind=Search

type Lineweaver in the author box, and press search.

 

You'll find a lot of interesting stuff. One thing you'll see is this

http://arxiv.org/abs/astro-ph/0401024

The Galactic Habitable Zone and the Age Distribution of Complex Life in the Milky Way

Charles H. Lineweaver (1 & 2), Yeshe Fenner (3), Brad K. Gibson (3) ((1) UNSW, (2) Macquarie University, (3) Swinburne University)

9 pages, 4 figs. Published in Science, 2 January 2004

(Submitted on 5 Jan 2004)

 

"We modeled the evolution of the Milky Way to trace the distribution in space and time of four prerequisites for complex life: the presence of a host star, enough heavy elements to form terrestrial planets, sufficient time for biological evolution and an environment free of life-extinguishing supernovae. We identified the Galactic habitable zone (GHZ) as an annular region between 7 and 9 kiloparsecs from the Galactic center that widens with time and is composed of stars that formed between 8 and 4 billion years ago. This GHZ yields an age distribution for the complex life that may inhabit our Galaxy. We found that 75% of the stars in the GHZ are older than the Sun."

[JamesBrown]

I can tell you, from first hand experience, why I haven’t found ET yet and I believe it’s the same problem with SETI@Home.

 

I have built and now operate a waterhole SETI station (http://www.SETI.Net). It runs 7 X 24 (or as near as I can make it). I have been building the station for many years and now its on line. During construction I was busy with all the details and had not put much thought into the Fermi paradox which directly affects my small efforts. Now that the station is complete its time to do this thought process.

 

I made a calculation on the number of ‘channels’ I had to examine on my station. Here are the numbers:

Since you are all computer literate so you understand the concept of address space. If your computer has a gig of main memory and each address of that gig is a byte (8 bits) wide then you have an address space of 1,000,000,000 X 8 bits or 8 Gigabits. SETI Net has its own address space:

1. The Paraclipse antenna is 12 foot in diameter. At 1420 MHz this equates to a half power beam width of about 3 degrees (HPBW).
   
2. The antenna can be positioned in declination between -35 and +27degrees. Based on 3 degrees BW this is about 20 positions of DEC.
   
3. This declination band moves past the antenna every 24 hours of RA (360 degrees of earth rotation). At 3 degrees this is 120 positions of RA.
   
4. The Band Pass Filter (BPF) just after the LNA has a pass band from 1375 MHz to 1475 MHz for a total of 100 MHz wide search band.
   
5. The Icom R7000 receiver running with the DRM module has an Audio Band Width of 20,000 Hz (ABW)
   

So the address space of SETI Net is:

(BPF/ABW) * (RA/HPBW) * (DEC/HPBW) =

(100 E6 / 20 E3) * (360/3) * (62/3) = 12,000,000 channels to surf.

 

I spend 2,000 seconds on each channel so: ~ 2.4E10 seconds or ~ 3,300 years to look ONCE in all my address space

[[Tycho?]]

1) Aliens dont want to colonize space, for many potential reasons.

 

2) Local supernovae or some other phenomenon exterminates or severely sets-back life in a region of space.

 

3) There is something which makes intersteller space travel more difficult that we assume. Now, its pretty damn difficult already, simply due to distances. But our understanding of the area outside the heliosphere is limited, and there could be some property of the space that would further hinder space travel (ie extra high energy particles, or something more exotic that we dont yet understand.)

 

The unlikely hood of live appearing in the first place seems decent, but life has shown to be quite tenacious and our lack of understanding on how life formed in the first place makes me not want to include this on my list.

 

As well, aliens could simply be so advanced that we have no way of detecting them or their signals.

[CPL.Luke]

well if you consider the numbers involved, if every star in the galaxy has an earthlike planet and earth has only had detectable intelligent life for the past 100 yaers, than the probability of finding a planet with intelligent life on it is actually very low...

[foodchain]

well if you consider the numbers involved, if every star in the galaxy has an earthlike planet and earth has only had detectable intelligent life for the past 100 yaers, than the probability of finding a planet with intelligent life on it is actually very low...

 

 

That’s a good point. Thinking on the question the amount of time it has taken for light from various "points" in the universe to reach earth is an indication of anything, signals from intelligent life, if not somehow derailed from a course to the earth by anything would have to compound with the evolution of solar systems, galaxies, planets, and then the evolution of life which would have to then take the course leading to a species or some form of a living thing at any rate that uses the technology we do or something similar. So in reality it might be another million years before a message gets to us in my opinion, to go on that us and them might be extinct if not something completely different at that point.

 

This Fermi guy makes it sound as if life only exists in certain parameters and has a guaranteed direction or modus to evolution, I don’t think you can really say that past speculation and assumption of course at this point.

[bascule]

It's my belief that abiogenesis resulting in something as complex as a prokaryote is an extraordinarily unlikely event. My guess is that most autocatalytic reactions which could eventually give way to self-sustaining and self-replicating life systems fizzle out of the necessary chemical components before they're able to reach that stage.

[foodchain]

It's my belief that abiogenesis resulting in something as complex as a prokaryote is an extraordinarily unlikely event. My guess is that most autocatalytic reactions which could eventually give way to self-sustaining and self-replicating life systems fizzle out of the necessary chemical components before they're able to reach that stage.

 

 

From what we can create of a primordial earth in relation to the nature behind biopoiesis most everything needed for life can be created in laboratory conditions. Here is my list of why I don’t think we have cracked it yet. One, I don’t think you can fully recreate what might be necessary in a laboratory, that’s the big one to me. The other one is the idea that what did lead to life might be a process that takes an incredibly long time.

 

Protobionts have my bet for the best place to start. During geological differentiation the primordial soup was to be something not so small also in terms of physical size. Tracing possible avenues of early life though does not suggest it being present everywhere though, at least not all at once. So the reality as I see it or the trick really is how you would call it autocatalysis behavior, but one that basically is an attempt to maintain equilibrium.

 

For instance in photochemistry, not to make any connection to photosynthesis or early bacteria. In the chemistry itself, or in a compound that conducts a reaction via light, its not the entire compound itself that is reactive, or if memory serves not always. Its parts of it, and then its variables such as the light itself or intensity. Then you have isomers of course, which can exhibit activity, such as optical isomers. The point I am trying to get at is the relationship of chemicals, or reactions of and energy or enthalpy I guess, don’t know if its proper use here.

 

In geologic terms, or primordial soup terms, I don’t know if we can account fully for the make up of such a system, or the earth at that point, let alone what I feel is key which is the amount of free energy available. As I see it, the reason people like oparin hit a brick wall may not be they had it wrong, it could simply be they did not understand simply the scope of the reaction mechanism or the very possible reality that such might have to be enormous and require an impractical amount of time to do. Following evolution currently, its from prokaryotes that eukaryotes came from, if at all possible the only real logical connection is to think that its the same natural process to the origin of life itself. To simply give out on a question because its difficult, well, that very well may damn most of science. As for odds, well what’s the odds of anything really.

[SkepticLance]

The Fermi Paradox states that, with all the billions of star systems in the galaxy, how is it that none seem to have spawned an intelligence that has visited Earth?

 

The opposite view comes from the Drake Equation, which was popularised by Carl Sagan. It goes ....

 

 

The number of civilisations in our galaxy = The rate of formation of suitable stars X The fraction of those stars with planets X The number of planets per star system in the 'liquid water' zone X The fraction of those planets where life developed X The fraction of planets with life where intelligence developed X The fraction of those planets where technology developed X the length of time these civilised species survive

 

Professors Drake and Sagan picked numbers out of the air for each variable and calculated that our galaxy has 1,000,000 civilisations.

 

Hence the paradox. Where the hell are they?

 

As others in this thread have said, it is not a problem getting out into the galaxy. NASA scientists have estimated that it is possible in theory to develop space craft that could travel at up to 0.2c. It is easy to calculate that, with such space craft, an intelligent species could colonise the entire galaxy to the point of overpopulation in a few million years.

 

And they have had time. About 10% of the galaxy is 2 billion years older than our sun. If Drake and Sagan are right, that means 100,000 species with a head start of 2 billion years.

[foodchain]

The Fermi Paradox states that, with all the billions of star systems in the galaxy, how is it that none seem to have spawned an intelligence that has visited Earth?

 

The opposite view comes from the Drake Equation, which was popularised by Carl Sagan. It goes ....

 

 

The number of civilisations in our galaxy = The rate of formation of suitable stars X The fraction of those stars with planets X The number of planets per star system in the 'liquid water' zone X The fraction of those planets where life developed X The fraction of planets with life where intelligence developed X The fraction of those planets where technology developed X the length of time these civilised species survive

 

Professors Drake and Sagan picked numbers out of the air for each variable and calculated that our galaxy has 1,000,000 civilisations.

 

Hence the paradox. Where the hell are they?

 

As others in this thread have said, it is not a problem getting out into the galaxy. NASA scientists have estimated that it is possible in theory to develop space craft that could travel at up to 0.2c. It is easy to calculate that, with such space craft, an intelligent species could colonise the entire galaxy to the point of overpopulation in a few million years.

 

And they have had time. About 10% of the galaxy is 2 billion years older than our sun. If Drake and Sagan are right, that means 100,000 species with a head start of 2 billion years.

 

It all sounds good but in all of it you have to then state that intelligent life, equal to or greater then at least of humans is an ultimate product of evolution. I would simply like to state barring the massive event that ended the existence of the dinosaurs evolution seemingly did not produce highly intelligent creatures to rule the planet. I just think its a serious fallacy to state that evolution will occur in a giving situation, or life for that matter, I think its also a major fallacy to think life needs a certain chemistry, and I also think its a major fallacy above all to say evolution is some perfect function, simply being going from natural history in any regard that’s simply not the case, its contradictory to natural selection first of all. What can survive will, its nothing more then that. If life occurs on some planet using a different chemistry then life on earth and the pinnacle of such after billions of years in context of the environment is conical slime molds using acid to make certain ions from minerals for energy or food with motility provided via explosions that propels there type of “dna“ to other areas in a cave, well who is to disagree, all we have is life on earth currently to compare to. To add to this sea vent communities were a type of life considred impossible by the field of biology in general prior to the discovery of such. There is just so many assumptions in all of this its not even funny.

[SkepticLance]

To foodchain

 

I agree with you totally.

 

My post was more along the lines of explaining the dilemma. The solution is, I am sure, along the lines you propose.

[Widdekind]

In the spirit of Stephen Webb's book, If the Universe Is Teeming with Aliens ... Where Is Everybody?: Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life, this author offers:

 

 

Solution 51 -- Aliens are Predators

 

According to Webb (p.113),

One reason why ETCs

[Extra-Terrestrial Civilizations]

might choose to keep quiet is

fear

. When an ETC broadcasts to space, it reveals its location, and perhaps level of technology. Any neighbors who are listening may be

aggressive

...

Perhaps caution is a general trait among advanced intelligences

.

I offer that this is due to Natural Selection -- the Milky Way Galaxy is populated by an advanced Predatory Civilization, that has already annihilated -- to wit, "predated" -- all the unwary intelligences in our Galaxy.

 

Indeed, Webb proposes basically this hypothesis, but uses the word "Berserker" instead of "Predator" (p. 112). By but replacing these two words, in Webb's proposal, we have that:

ETCs have either been prevented from arising by

[Predators]

, wiped out by

[Predators]

, or else are keeping quiet for fear of attracting

[Predators]

... So, why have

[Predators]

silenced all other

Civilizations

, but left us alone? We could argue that

[Predators]

destroy only

Technological Life-forms

, and need a "trigger" -- presumably the detection of

Radio Waves

-- before they begin to work.

Note that yet another of Webb's proposals is called "They are here, and are meddling in Human affairs". This "Berserker-Predator" hypothesis succinctly sets a pre-Industrial Glass Ceiling upon emerging Civilizations, neatly explaining the apparent lack of the same in our skies.

[D H]

Solution 51 -- Aliens are Predators

Correction: That is Webb's Solution 22, not 51 (He only has 50 solutions, after all).

 

I prefer a variant of #50: They aren't there. My variant: If they are out there, they are way out there. We are, for all practical purpose, alone. IMHO, Intelligent life is extremely rare, and when it does manage to beat the odds and form on some planet it is extremely short-lived.

 

What makes the Earth so special? Nothing in particular. What makes the winner of the $200 million lottery jackpot special? Nothing. He just got lucky.

 

How did Earth get lucky?

1. We have one Sun, not two or more. Single stars are not the norm. Most star systems occur in multiples. What are the odds of an Earth-like planet maintaining a stable orbit in the habitable zone of a multi-star system for billions of years?
   
2. Our Sun is rather stable. Even amongst main sequence stars we have observed stars with much greater variability than the Sun. Until we know more about how stars behave, the relative stability of our Sun might be completely normal -- or we might be incredibly lucky.
   
3. Other nearby stars haven't wiped us out. A nearby supernova, or a not-so-nearby gamma ray burst, could spell instant death for a planet. The long-term gravitational perturbations by a nearby star could spell a drawn out death for life on a planet. Stars much closer to the galactic core than our Sun are much more likely to suffer these catastrophic and long-term perturbations than are stars further from the core.
   
4. We have metals, and we have metals heavier than iron. Even if civilization had formed, without metals civilization could not have advanced beyond little huts and villages. First generation stars didn't produce much "metal" (elements heavier than helium), period. Metallicity in general drops with distance far from the galactic core. Our Sun is at a distance that balances the the catastrophic effects of proximity to the core against the lack of metallicity far from the core.
   
5. Jupiter didn't go kamikaze. Most of the planets discovered to date are hot jupiters. While that does not mean that most planetary systems have hot jupiters (it might just mean that hot jupiters are a whole lot easier to find), that some systems have hot jupiters does reduce the likelihood that Earth-like planets will form.
   
6. We have a big honkin' Moon. How unlikely is that? (The answer is, we don't know; but it seems incredibly fluky.) Some conjecture that the Moon was essential for the formation and advancement of life (I'll try to dig up some references).
   
7. Complex life formed. Based on a sample size of one (the Earth), it may not be all that unlikely for simple life to form given the proper conditions. Based on a sample size of one again, formation of complex life is a different issue. Life remained simple on the Earth for the majority of the time that life has existed.
   
8. Life didn't commit suicide. It tried. It tried to do so multiple times, perhaps. Snowball Earth resulted from life making the sky clear. The Permian-Triassic extinction may have been the result of life being a bit over-exuberant during the Permian.
   
9. We have fuel. The Earth had its Carboniferous and Permian periods where life was a lot more productive than it is now. Imagine a planet where life managed to just barely survive but still managed to form a truly intelligent species. How would this intelligent life move into our equivalent of a modern age without sufficient hydrocarbons?
   
10. Intelligent life formed. While near-intelligent life and haphazard use of tools has independently arisen multiple times (apes, octopi, parrots, dolphins, maybe some dinosaurs), Homo habilis pretty much stands alone in its complex use of tools.
    
11. Communicative life formed. Homo sapiens talks. A species with a brain much bigger than ours that cannot formulate complex thoughts or communicate them others is not truly intelligent. One of the biggest hurdles in any large-scale engineering endeavor such as getting people to the Moon is communication.
    
12. Life didn't kill us. It tried. Multiple times. The Antonine Plague, the Plague of Cyprian, the Black Death, the Third Pandemic, Spanish flu, just to name a few.
    
13. We didn't kill ourselves. We've tried. Multiple times. Modern technology has made it far easier to do so. Perhaps some of us will succeed the next time around.

 

With all of those hurdles, it is not surprising to me that intelligent life is extremely rare.

[Martin]

... barring the massive event that ended the existence of the dinosaurs evolution seemingly did not produce highly intelligent creatures to rule the planet. I just think its a serious fallacy to state that evolution will occur in a giving situation, or life for that matter, I think its also a major fallacy to think life needs a certain chemistry, and I also think its a major fallacy above all to say evolution is some perfect function, simply being going from natural history in any regard that’s simply not the case, its contradictory to natural selection first of all. What can survive will, its nothing more then that...

 

To foodchain

I agree with you totally... The solution is, I am sure, along the lines you propose.

 

I see no reason to agree totally with foodchain's line of argument (which strikes me as full of straw and not terribly coherent.) The Fermi question is still complicated and interesting, IMO. Nor do I see any reason to be sure, that the solution is along the lines suggested by foodchain.

 

Maybe it is time to reopen discussion and hear what members think.

 

EDIT: I just saw DH's post, which looks pretty good!

Edited May 3, 2009 by Martin

[D H]

Since 13 is an unlucky number, I'll add a few more hurdles:

14. Religion. How many civilizations have arisen, only to throttle any scientific advances? See

this thread

.

 

15. Peak oil. How many civilizations have arisen, only to consume all resources and send themselve back to the stone age? See multiple threads.

 

16. Been there, done that. How many civilizations have arisen, sent the equivalent of people to the their moon, but then stopped because they have been there and done that?

 

17. Cyber space. How many civilizations have arisen and then stagnated because they found their equivalent of the internet far cooler than real life?

---

Merged post follows:

Consecutive posts merged

Completely off-topic: What's with the green background on indents?

[iNow]

Completely off-topic: What's with the green background on indents?

 

End of page 1 and beginning of page 2:

http://www.scienceforums.net/forum/showthread.php?t=37360

 

The frame box around indents was taken away, then put back, but with a different color to separate it from quote tags.

[Martin]

 

The frame box around indents was taken away, then put back, but with a different color to separate it from quote tags.

 

Test

test

test

test

 

evolution is just continuing, like at the waterline boundary (sea-land, water-air), or at the boundary between Siberia and Alaska. Now it's just a different boundary, but the evolutionary process is the same.

 

Life forms spread if they have evolved the ability and inclination. If not, they don't.

 

In some sense selection favors those able/inclined to spread because they come to occupy more of the environment.

Edited May 3, 2009 by Martin

[Widdekind]

Back in the 1960s AD, Geologists thought that deep ocean Life was impossible, down in the Abyssal blacknesses beneath the surface Photic Zone, where Photosynthesis is no longer possible. But, the discovery of Hydro-Thermal Vent systems, along the Mid-Ocean Ridges, by Bob Ballard and others, proved that Chemosynthetic Life thrives, even w/o Sunlight*.

*

National Geographic Channel

Naked Science -- Dangers of the Deep

(TV)

Now, free-floating, inter-stellar, Rogue Planets could conceivably be quite common, for example, in the Orion Nebula*. Large Rogue Planets could probably keep thick Atmospheres, which would insulate them against the cold blackness of space. Beneath such a blanket, Geothermal processes could keep the planet warm enough for water. However, they would "be difficult to detect due, to the intrinsically weak Thermal Microwave Radiation emissions emanating from the lower reaches of the Atmosphere"**. Note that most Rogue Planets are probably sub-stellar-mass "failed stars", as opposed to "ejected planets"***.

*

http://archives.cnn.com/2000/TECH/space/10/06/space.planets.reut/index.html

**

http://en.wikipedia.org/wiki/Interstellar_planet

,

http://www.daviddarling.info/encyclopedia/R/rogueplanet.html

***

http://en.wikipedia.org/wiki/Oph_162225-240515

 

CONCLUSION (??): The "Predator Homeworld" may be a large Rogue Planet, supporting a complex, and exclusively Chemosynthetic, Ecology, including an advanced Extra-Terrestrial Intelligence (ETI) "Predator".

[Airbrush]

Carl Sagan was instrumental in getting our position in space engraved in Voyager, so that ETs can find us someday.

 

Recently I heard Michio Kaku suggest that may not be wise. Considering the possibility that ETs could adversely impact us, or eat us or destroy us and take Earth, maybe we should consider not leaking our TV programs to outer space?

[Martin]

Has everybody interested in this thread already looked at the Wikipedia article?

 

http://en.wikipedia.org/wiki/Fermi_paradox

 

I don't always think Wiki articles are reliable or balanced---quality varies. But this one looks pretty good to me, given my limited perspective on this question. I'd like to know other people's reactions to it.

[Airbrush]

I propose there is no paradox. The term "Fermi Paradox" was coined at a time scientists assumed there were a lot of ETs in our neighborhood. They all watched Star Trek! Perhaps there are so FEW that they are effectively isolated for a long time to come, maybe indefinitely.

Edited May 4, 2009 by Airbrush

[Severian]

It's my belief that abiogenesis resulting in something as complex as a prokaryote is an extraordinarily unlikely event. My guess is that most autocatalytic reactions which could eventually give way to self-sustaining and self-replicating life systems fizzle out of the necessary chemical components before they're able to reach that stage.

 

I think I would agree with that.