who this not know, only for Info

The Fermi paradox is a paradox proposed by physicist Enrico Fermi that questions the probability of finding intelligent extraterrestrial life. More specifically, it deals with the attempts to answer one of the most profound questions of all time: "Are we (human beings) the only technologically advanced civilization in the Universe?" The Drake equation for estimating the number of extraterrestrial civilizations with which we might come in contact seems to imply that we should not expect such contact to be extremely rare, depending on the values that are put into the formula. Fermi's response to this conclusion was that if there were very many advanced extraterrestrial civilizations in our galaxy, the Milky Way, then, "Where are they? Why haven't we seen any traces of intelligent extraterrestrial life, such as probes, spacecraft or transmissions?" Those who adhere to the premise behind the Fermi paradox often refer to that premise as the Fermi principle.


Fermi paradox

Greetings from Germany NRW
Ulli S@h Berkeley's Staff Friends Club m7 ©

Thanks for the link Sir Uli. A very interesting read, the total sum of my personal knowledge has expanded as a result. ;-)

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Another article here by Seth Shostak that I found interesting.

This quote from the article sums up the problem for True Believers in ET:

" ... 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."

If intelligent life exists anywhere, and they are even remotely like us, and were able to maintain anything close to the rate of innovation we have (First flight to Space flight in less than 100 years, plus the ability to manufacture starflight fuel - anti-matter) - then to believe, you really must explain why we are not tripping over aliens everywhere we look.

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- Skeptic - "... and there is no intelligent life in Washington D.C. either."

> Another article <a> href="http://www.space.com/searchforlife/shostak_paradox_011024.html"> here by
> Seth Shostak[/url] that I found interesting.
>
> This quote from the article sums up the problem for True Believers in ET:
>
> " ... the Fermi Paradox is a remarkably strong argument.
snip
> 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."
>
>
> If intelligent life exists anywhere, and they are even remotely like us, and
> were able to maintain anything close to the rate of innovation we have (First
> flight to Space flight in less than 100 years, plus the ability to manufacture
> starflight fuel - anti-matter) - then to believe, you really must explain why
> we are not tripping over aliens everywhere we look.
>
Firstly, Skeptic it's a bit egotistical to assume intelligent alien life would resemble humanity.
Secondly, you seem to be assuming FTL travel.
Thirdly, (and most importantly) we have only been actively observing for ET signals for 40 (very) odd years, and most of the observation has been done in the Northern Hemisphere.
PS: I don't neccesarily disagree with the Fermi Paradox.
PPS: It is a very interesting article, and no I can't explain why were not tripping over aliens.

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Need help? Check out the excellent Unofficial BOINC-Wiki!
'We are the BOINC. Prepare to be assimilated.'

Some have suggested They are out there and are simply waiting for us to civilize ourselves sufficiently to make decent neighbors.
It's a bit of an intellectual dodge of Fermi's logic, but it has an appealing, if somewhat self-deprecating, logic of its own that I like.

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"I wouldn't want to make first contact with a species that has me as a member?"

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> Some have suggested They are out there and are simply waiting for us to
> civilize ourselves sufficiently to make decent neighbors.
> It's a bit of an intellectual dodge of Fermi's logic, but it has an appealing,
> if somewhat self-deprecating, logic of its own that I like.
>

I guess it's just too expensive to send a manned ship several dozen lightyears away.
(I'm assuming here that not every star system is interesting enough to visit)

Such a ship would have to travel for hundreds or thousands of years, and would probably weigh thousands of tons.

There might be dozens of small probes orbiting the sun right now, but we won't be able to detect them as long as they don't try to actively communicate with us.

The most sensible thing IMHO is using radio signals (traveling at light speed) to communicate. (Costing maybe 1 billionth of a manned ship).

Maybe we're just listening on the wrong wavelength (1420Mhz) right now.

If we actually catch up with the current seti data, I think the best thing to do
would be listening at a broader spectrum of radio signals.

Regards Hans

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found the original Link


Fermi's Paradox III: Zookeepers, Alien Visitors, Or Simple Life; How Can We Explain Our Isolation

Greetings from Germany NRW
Ulli S@h Berkeley's Staff Friends Club m7 ©

>"Firstly, Skeptic it's a bit egotistical to assume intelligent alien life would
> resemble humanity." - five and a half

What exactly is your point? That aliens are so unlike us that that we are wasting time looking for radio signals with SETI? That far advanced alien civilizations are not interested in exploring the galaxy? SETI, almost by definition, makes the assumption that aliens are like us enough that there is some basis for understanding or communication in the radio waves we are searching the sky for. - Skeptic

-----------------------------

> "Secondly, you seem to be assuming FTL travel." - five and a half

I assume no such thing. I quoted a Seth Shostak article that makes the point that even assuming travel at only 1% or 10% of the speed of light, any civilization that lasts for a million years or so, should have colonized the entire galaxy by now, as the Galaxy is much much older than that.

For illustration, this is a typical calculation I found at another website that makes the same point:

"To contemplate inter-stellar travel ...A more realistic velocity might be 1/100 or perhaps better 1/10 of light velocity. Much more than 1/10 gets into bigger problems than I think are worth solving, i.e. if you are willing to spend your lifetime traveling through space, what difference does "How long" make?

At 1/10 c, it will take a maximum of 10 x 100,000 light years (galactic diameter) = 1,000,000 years to cross the galaxy. Now add the above development time and we get ...

(38 x 1000) + 1,000,000 = 1,038,000 years
high speed colonization

(38 x 100,000) + 10,000,000 = 13,800,000 years
low speed colonization

There are of course many other factors which might slow up or speed up colonization. Any colony or home planet might send out many more than just two expeditions. Why not one every 100 years after they are fully developed? It could be like dodge'em cars out there. Or maybe they get lazy and just kinda' peter out after going a few hundred light years. The point here is that if any civilization wished to colonize the galaxy ... and ... travel between stars is possible ... and ... there are many civilizations out there ... then ... the galaxy should already be totally explored and colonized ... and long ago ... just by the statistics of the situation."

http://ebtx.com/mars/disperse.htm

The author on that page is apparently invoking the Fermi Parodox in order to to make the case that UFO's are real, a conclusion I am even more skeptical about than the prospects of finding one through SETI. He also ignores the effects of relativisitic "time dilation" which would permit a star traveleler at higher speeds to travel across the galaxy within one lifetime - even a a human lifetime. Nevertheless, his calculation is illustrative of the compelling statistics of the Fermi paradox. - Skeptic

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"PPS: It is a very interesting article, and no I can't explain why were not
> tripping over aliens." - five

"Occams Razor" says that the simplest explantion is usually the right explanation. In this case, you cannot get much simpler than this:

The reason we don't find anyone, is that no one is home.

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- Skeptic - "... and there is no intelligent life in Washington D.C. either."

Skeptic- Very well thought out. The only question is how flawed (or perhaps a better term would be lacking) is our data. If we are to assume that there is a number of NEC (non earth civilizations) out there, why haven't we found them?

Who knows, how would we act if we found a less advanced planet? Either today or when we actually reach a point we could travel to said planet. Also keep in mind at the ranges we're talking about compressed signals may look like background noise (the whole SETI thing could be a waste of time if this is true).

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Still looking for something profound or inspirational to place here.

> "Some have suggested They are out there and are simply waiting for us to
> civilize ourselves sufficiently to make decent neighbors.
> It's a bit of an intellectual dodge of Fermi's logic, but it has an appealing,
> if somewhat self-deprecating, logic of its own that I like." Dr. Bob

> "The only question is how flawed (or perhaps a better term would be lacking)
> is our data. If we are to assume that there is a number of NEC (non earth
> civilizations) out there, why haven't we found them?
> Who knows, how would we act if we found a less advanced planet? Either today
> or when we actually reach a point we could travel to said planet. Also keep in
> mind at the ranges we're talking about compressed signals may look like
> background noise "- Ghostwolf
==================
These are as good an explanation as any to explain away the Fermi Paradox. There are many more:

From the Wikepedia Article referenced by Sir Ulli that kicked this thread off:

"They exist - but most people have yet to see them (UFO true believer favorite)
They exist - but we have missed them
They exist - but do not communicate with us
They exist and communicate - but we are either not listening or are dismissing the evidence

some have interpreted the accounts of mystics, shamans, and channeling as evidence for a type of ongoing communication. In support of this view it has been posited that if the brain can somehow operate using quantum mechanical processes, as proposed by Roger Penrose and Stuart Hameroff, then in principle a type of nonlocal communication may be possible, which may then be enhanced or facilitated by traditional shamanic, meditation, or kundalini yoga techniques.

In addition, Terence McKenna and others who have experimented with Dimethyltryptamine (DMT) experiences have suggested that aliens (perhaps originating from other 'dimensions' or parallel universes), are communicating with humanity through unidentified processes which are activated by DMT.
Although classical communication in the context of information theory is not possible using quantum nonlocal correlations, supporters of this view believe that it may explain the 'garbled', associative, and inspirational nature of the 'messages' recorded in the world's religious and anthropological history.

another possible explanation — that someone, or something, is destroying intelligent life in the universe as fast as it is created.

Another alternative is simply that they destroy themselves... Technological civilizations may usually or invariably destroy themselves (via nuclear war, biological warfare, grey goo, or in a Malthusian catastrophe after destroying their planet's ecosphere) before or shortly after developing radio or spaceflight technology."

From Sheth Shostaks subsequent article also reference by Sir Ulli:

"aliens have done cost-benefit analyses that show interstellar travel to be too costly or too dangerous to warrant ambitious colonization efforts.

An alternative suggestion that would explain our apparent solitude is that the Galaxy is urbanized, and we’re in a dullsville suburb.

...we’ve been singled out for special treatment: we are an exhibit for alien tourists or sociologists.The presence of aliens on Earth would neatly resolve the Fermi Paradox."

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

All of these explanations of the paradox are equally good.

We can each choose our favorite from these, or many more, to explain it all away.

You choose yours, I'll choose mine.

As explained in my last post, I choose the simplest:

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- Skeptic - "... and there is no intelligent life in Washington D.C. either."

Skeptic- I don't post much on this board (lurk from time to time). Please pardon my rhetorical first question. I was far more interested in the second one: How would (should) we approach an underdeveloped civilization upon discovering one? Which wasn't targeted specifically at you. I am curious though (relating this belief to religion) are you an Atheist? Or are you Agnostic with a heavy bias against?

Since it's only fair: I'm Agnostic with a mild bias for life elsewhere. Any time I sound like it is a certainty, it's just thinking through the scenario. I actually need to throw myself into the situation (mentally) to really give a fairly honest answer.

edit: My apologies for a largely philosophical post (in the future I'll try to stay more on subject and in the confines of the board)

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Still looking for something profound or inspirational to place here.

snip
> SETI, almost by
> definition, makes the assumption that aliens are like us enough that there is
> some basis for understanding or communication in the radio waves we are
> searching the sky for. - Skeptic
>
Just because I support the aims of SETI doesn't mean that I'm incapable of conceiving that they might be mistaken. Unanimity of purpose _is_, after all, one of the major defects of the criticisms of Fermi's Paradox.

-----------------------------
snip
> > "Secondly, you seem to be assuming FTL travel." - five and a half
>
> I assume no such thing.
>
snip
Fair enough, my mistake, but you _did_ mention anti-matter and I have been watching _far_ too much Star Trek recently :)

--------------------------------------------
snip
> "PPS: It is a very interesting article, and no I can't explain why were
> not
> > tripping over aliens." - five
>
> "Occams Razor" says that the simplest explantion is usually the right
> explanation. In this case, you cannot get much simpler than this:
>
> The reason we don't find anyone, is that no one is home.
>
Why should we be knee deep in aliens, assuming they exist? This is not 'The Trouble With Tribbles'.

I would also like to restate that the data we have is still very incomplete.

---

Need help? Check out the excellent Unofficial BOINC-Wiki!
'We are the BOINC. Prepare to be assimilated.'

This is very intresting but I'd like to put in a few thoughts.
First this planet(4.6 billion years old) has under gone 11 extinctions ,5 of which were major (85%-95%), over the last 600 million years.
assuming a ET civilization suffered at least one,and evolved at a rate similar to ours they would be extemely advanced and would regard us as cockroches by comparison.Say, when was the last time you sat down and had a conversation with a bug.If ET evolved similar to us,they would be stumbling around such as we are now.
If ET was unlucky but lucky enough to survive they'd be living in caves or something like would be more concerned about the next meal than Howdy Doody.
Second the first radio signals from earth are nearly 100 years old.Assuming anybodies even listening at all it would take "them" as long to reply with similar technology.Assuming they could translate right away.How many years did it take us to figure out ancient egyptian WITH the rosseta stone?

I get a real kick out of the skeptics out there.They want instant results ussually.If you look at the vastness of our galaxy let along the rest of the universe it becomes mind boggling.The few extra solar planets that we've discoverd just in the last 20 years over the last 2billion years of evolution is less than a grain of sand in comparison to the rest of the universe.With these discoveries and with SETI,regardles if it works or not,at least it's a start.At least we'er trying.

My biggest problem with the Fermi Paradox is to me it makes a few too many assumptions.

One is that you can apply a mathematical model to expansion simply governed by whatever value you give for speed of any hypothetical spaceship. Expansion in human history was certainly facilitated by larger, more reliable technology, but the social, political, environmental, etc factors that affected our expansion across the globe are legion. Our expansion simply doesn't correspond to any curve of speed of travel, and it's fallacious to assume any alien species would follow a simple linear trend of expansion.

To put that expansion trend in perspective, if a do-it-yourself homeowner builds a garage, they can be said to have established an expansion rate by calculating the increase in square feet by the number of years they've owned the house. By the Fermi logic, eventually the expansion must continue until the house is impinging on the neighbors' properties.

Another is the assumption of practicality. So far, we have not found it practical to build spacegoing ships to even colonize our own system, let alone other star systems, and there as yet isn't even a projected technology to make the energy requirements and life support mechanisms possible. The Fermi Paradox just assumes suitable technology will be available and appealing to advanced civilizations, and gives this as the reason why they can't exist.

Or you could apply the Towel Paradox: n&divide;&infin;=&#x25cb;.&#x25cb;&#x25cb;&#x25cb;&#x25cb;&#x25cb;&#x263a;&#x25cb;&#x25cb;&#x25cb;&#x25cb;&#x25cb;&hellip;

It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited number of worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is zero, and that any people you may meet from time to time are merely the products of a deranged imagination.

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> "My biggest problem with the Fermi Paradox is to me it makes a few too many assumptions." - mura

As opposed to, say - the Drake Equation? I guess there are no assumptions there to worry about.

"> From this it follows that the population of the whole
> Universe is zero, and that any people you may meet from time to time are
> merely the products of a deranged imagination." - neo


Problem being, of course, the little detail that we have not actually met any "people" yet. If we had, there is no paradox.

Unless you are saying that you have met them, Neo.

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- Skeptic - "... and there is no intelligent life in Washington D.C. either."

I think the "Towel Paradox" it also applies Terrans, but I do see dead people...

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> As opposed to, say - the <a> href="http://en.wikipedia.org/wiki/Drake_equation"> Drake Equation? [/url]
> I guess there are no assumptions there to worry about.

For one, just mentioning any noticeable flaws in one theory does not prove the other true.

For another, the Drake equation merely provides an equation for mathematical speculation. The equation itself is simply a list of questions to be answered, i.e the values for the variables themselves. Unlike the Fermi Paradox, it was never meant to be logical proof of anything.

> I think the "Towel Paradox" also applies to Terrans, but I do see dead people..." -neo

Who doesn't? There were a couple of 'em hanging around my home office, so I got them interested in SETI, and have them crunching Work Units on my home systems while I'm at work.

Its just those sneaky aliens that no one ever seems to see or hear from. While I'll give you points for creativity, I'm afraid that spotting Terrans does exactly nothing to undermine the Fermi Paradox. Nice try.

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- Skeptic - "... and there is no intelligent life in Washington D.C. either."