Where is Everybody? The Fermi Paradox:

Beyond “Fermi’s Paradox” I: A Lunchtime Conversation- Enrico Fermi and Extraterrestrial Intelligence
by PAUL PATTON on APRIL 7, 2015

Please Register or Log in to view the hidden image!

Nuclear physicist Enrico Fermi won the 1938 Nobel Prize for a technique he developed to probe the atomic nucleus. He led the team that developed the world’s first nuclear reactor, and played a central role in the Manhattan Project that developed the atomic bomb during World War II. In the debate over extraterrestrial intelligence, he is best known for posing the question ‘Where is everybody?’ during a lunchtime discussion at Los Alamos National Laboratory. His question was seen as the basis for the “Fermi Paradox”.Credit: Smithsonian Institution Archives.

It’s become a kind of legend, like Newton and the apple or George Washington and the cherry tree. One day in 1950, the great physicist Enrico Fermi sat down to lunch with colleagues at the Fuller Lodge at Los Alamos National Laboratory in New Mexico and came up with a powerful argument about the existence of extraterrestrial intelligence, the so-called “Fermi paradox”. But like many legends, it’s only partly true. Robert Gray explained the real history in a recent paper in the journal Astrobiology.

Enrico Fermi was the winner of the 1938 Nobel Prize for physics, led the team that developed the world’s first nuclear reactor at the University of Chicago, and was a key contributor to the Manhattan Project that developed the atomic bomb during World War II. The Los Alamos Lab where he worked was founded as the headquarters of that project.

The line of reasoning often attributed to Fermi, in his lunchtime conversation, runs like this: There may be many habitable Earth-like planets in our Milky Way galaxy. If intelligent life and technological civilization arise on any one of them, that civilization will eventually invent a means of interstellar travel. It will colonize nearby stellar systems. These colonies will send out their own colonizing expeditions, and the process will continue inevitably until every habitable planet in the galaxy has been reached.

The fact that there aren’t already aliens here on Earth was therefore supposed to be strong evidence that they don’t exist anywhere in the galaxy. This argument actually isn’t Fermi’s and was published more than 25 years later by astronomer Michael Hart. It was elaborated in a paper published by the cosmologist Frank Tipler in 1980.

Fermi’s lunch conversation really did happen. Although he died just four years later of cancer, physicist Eric Jones published the recollections of the physicist’s luncheon companions more than thirty five years later. Among these companions were Edward Teller, Emil Konopinski, and Herbert York, all eminent physicists and veterans of the Manhattan Project. Teller played a central role in the development of the hydrogen bomb. Konopinskistudied the structure of the atomic nucleus, and York became director of Lawrence Livermore National Laboratory.

Please Register or Log in to view the hidden image!

Edward Teller was the head of the Theoretical Physics Division at Los Alamos National Laboratory during the Manhattan Project that developed the atomic bomb for World War II. After the war he was central to the development of the hydrogen bomb. He was one of Enrico Fermi’s lunch companions when he posed the famed question”Where is everybody?” Credit: Lawrence Livermore National Laboratory



During the walk to the Fuller Lodge, the physicists discussed a recent spate of UFO sightings, and a cartoon in the New Yorker Magazine depicting aliens and a flying saucer. Although the topic of conversation moved on as the group sat down for lunch, Edward Teller recalls “in the middle of the conversation, Fermi came out with the quite unexpected question ‘Where is everybody?’…The result of his question was general laughter because of the strange fact that in spite of Fermi’s question coming out of the clear blue, everybody around the table seemed to understand at once that he was talking about extraterrestrial life”.

In his account of the famed luncheon, Teller wrote “I do not believe much came from this conversation, except perhaps a statement that the distances to the next location of living beings may be very great and that, indeed, as far as our galaxy is concerned, we are living somewhere in the sticks, far removed from the metropolitan area of the galactic center”.

York recalled a somewhat more expansive discussion in which Fermi “followed up with a series of calculations on the probability of earthlike planets, the probability of life given an earth, the probability of humans given life, the likely rise and duration of high technology, and so on. He concluded on the basis of these calculations that we ought to have been visited long ago and many times over”.

According to York, Fermi supposed the reason we hadn’t been visited “might be the interstellar flight is impossible, or if it is possible, always judged not worth the effort, or technological civilization doesn’t last long enough for it to happen”.

So Fermi, unlike Hart, wasn’t skeptical about the existence of extraterrestrials, and didn’t view their absence from Earth as paradoxical. There is no Fermi paradox, there is simply Fermi’s question “Where is everybody?”, to which there are many possible answers. The answer that Fermi preferred seems to be that, either interstellar travel isn’t feasible because of the enormous distances involved, or Earth simply had never been reached by alien travelers.

Please Register or Log in to view the hidden image!

Herbert York was a Manhattan Project physicist, the co-discoverer of the neutral pi meson, and the first director of the Lawrence Livermore National Laboratory. He was one of Fermi’s lunch companions the day he posed his famed question about extraterrestrials. Credit: National Nuclear Security Administration

Interstellar distances are truly vast. If the entire solar system out to the orbit of Neptune were reduced to the size of an American quarter, the nearest star, Proxima Centauri, would still be about the length of a football field away. A practical starship would either need to travel very fast, at an appreciable fraction of the speed of light, or be capable of supporting its crew for a very long time. While either is theoretically possible, interstellar travel seems to present day humanity to be such a grandiose undertaking that it’s not clear whether any civilization would be able or willing to muster the enormous resources needed.

Where did the confusing of Fermi’s question with Hart’s argument come from? Carl Sagan mentioned Fermi’s question in a footnote to a 1963 paper. After the publication of Hart’s paper in 1975, Fermi’s question and Hart’s speculative answer became associated in many writer’s minds. Fermi’s question seemed to beg Hart’s answer, and “Fermi’s paradox” was born. According to Robert Gray, the term was coined by D. G. Stephenson, in a paper published two years after Hart’s.

Why is it important that Hart’s argument was never really made by the eminent physicist Enrico Fermi? Did Michael Hart and Frank Tipler really make a compelling case that extraterrestrial civilizations don’t exist in our galaxy? We’ll answer those questions in the second installment.

 

Log in or Sign up to hide all adverts.

Well someone has to be the first species to develop civilization, it might even be us.

But if it isn't, what would the real first species have thought about the Fermi Paradox?

 

Log in or Sign up to hide all adverts.

Is there a question in this thread or is this just the reposting of an article?

Please Register or Log in to view the hidden image!

 

Log in or Sign up to hide all adverts.

The galactic center is a high radiation area, which is bad enough, but is also host to some pretty chaotic and inhospitable celestial mechanics. If life ever evolved there, more extinction events would wipe them from existence more often. This probably means they never survive long enough either to communicate with other civilizations or move to a more peaceable neighborhood out here in 'the boonies' of the galactic neighborhood.

It already taxes our technological abilities in terms of low data rates and sophisticated error detection / correction ability to communicate with deep space probes beyond the range of a few tens of light years under the.most favorable conditions. It takes considerable smarts to manage to build computing engines with this capability. If we ever detect something from ET, that will be a minor miracle all by itself.

That ET civilizations exist is as certain as the facts that Fermi and Hart were both right and Teller was a hack undeserving of mention in the same sentence. I somehow doubt we will survive long enough to find or actually meet one.

 

we don't have any probes that far away.

if there isn't any other intelligent life in this galaxy then we are as good as alone. and this is being optimistic as this galaxy is pretty big.

 

I don't see a paradox. There could be life in the closest solar system and we still probably wouldn't know it.

 

Some of our early radio and television broadcasts and nuclear weapons detonations have already reached this far, and a few of those may have actually bounced and come back. When we can see 'I Love Lucy' reruns bounced off of an exoplanet, we might have a chance of finding ET with a receiver attached to a radiotelescope. If ET doesn't beam something directly at us at high power and for a long time, the chances are slim we would ever notice it.

A spectral signature for something like plutonium (non-naturally occuring) would be a dead giveaway that ET was playing with atoms.

I worked with some cutting edge error detection/ correction for most of my earlier career, including the first such application of Hamming codes to the Intelsat satellites. I know what can be accomplished as opposed to what is pitched to fund efforts like SETI.

 

Note that a galaxy has a habitable zone.

Closer to galactic center, there is too much orbital activity to allow a solar system to be stable long enough for life to evolve. Furthermore, there is a lot of radiation inimical to living creatures.

Farther from galactic center, the elements required for life are too scarce. In the future, the habitable zone will expand. Not sure how much.

BTW: While life seems likely to exist, technological cultures seem likely to be scarce. I have posted comments relating to this in more than one Thread.

My guess is that few (if any) galaxies have more than one technological culture & many have no such culture. The history of the Earth seems to suggest this POV.

Note that the Neanderthals & Denisovans seemed to have potential, but went extinct before evolving into a technological culture.

 

And of course we speak of "life, as we know it"......
And while galactic "Goldilock zones" are a reasonable summation, they are far less certain then individual stellar "Goldilock zones" and their inevitable variability over time, and as the star ages.
I would say as far as galactic Goldilock zones are concerned, life would have a far greater range then the reasonably narrow zones in individual stellar systems.

Yes, correct, technologically advanced civilisations are bound to be less numerous than microbrial and bacterial life, but I'm sure most cosmologists, Astrobiologists recognise that fact.

Well, yes that is a guess, but I'm not too sure how the history of the Earth suggests that a galaxy should only have one technologically advanced culture.

Yes, so?

 

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

The idea of the galactic habitable zone has been criticized by Nikos Prantzos, on the grounds that the parameters to create it are impossible to define even approximately, and that thus the galactic habitable zone may merely be a useful conceptual tool to enable a better understanding of the distribution of life, rather than an end to itself.[2] For these reasons, Prantzos has suggested that the entire galaxy may be habitable, rather than habitability being restricted to a specific region in space and time.[2] In addition, stars "riding" the galaxy's spiral arms may move tens of thousands of light years from their original orbits, thus supporting the notion that there may not be one specific galactic habitable zone.[3][4][5] A Monte Carlo simulation, improving on the mechanisms used by Ćirković in 2006, was conducted in 2010 byDuncan Forgan of Royal Observatory Edinburgh. The data collected from the experiments support Prantzos's notion that there is no solidly defined galactic habitable zone, indicating the possibility of hundreds of extraterrestrial civilizations in the Milky Way, though further data will be required in order for a definitive determination to be made.[29]
http://en.wikipedia.org/wiki/Galactic_habitable_zone

 

From my Post #8

From Paddoboy in Post #9

Apparently he missed my point.

The Neanderthals & Denisovans showed potential for developing into a technological culture, but went extinct before doing so.

Does the above not strongly indicate that intelligence does not necessarily result in the development of a technological culture?

As mentioned by me in other Threads, the history of the Earth strongly indicates that life will develop in any environment suitable for it. That same history also strongly indicates that evolution does not inevitably lead to the development of a technological culture.

Two known species (Neanderthals & Denisovans) showed as much potential as our early ancestors, but went extinct before evolving past a Stone Age culture.

BTW: As mentioned in another Thread, the octopus seems to have potential for intelligence, but never evolved to attain it.

To me, octopus history indicates that environmental pressure is required to cause potential to evolve into intelligence. The octopus has 3D movement & is capable of easily obtaining prey. It has no predators successful enough to threaten it.

The octopus has no environmental pressure for further evolution.

 

No I did not.

Yes.

Sure, but our own evolution indicates that it does happen.....How frequently we don't know as yet.

Even if the odds of Intelligence leading to a technological culture were a million to one, the numbers involved would indicate of it happening more then once in each galaxy.

 

We should take into consideration the amount of species on earth and how many of them actually evolved technological culture, which is one. So that's around 8 million species to 1, and that's only the species around today, most of the species has already gone extinct. Given the benefits of intelligence the stepping stone for evolution to actually achieve it has to be pretty big. A normal (for earth) way to survive in a energy effecient way doesn't seem to favour general intelligence, rather developing specific intelligence in a narrow field (if that could be called intelligence or simply instinct).

So given what we know about the earth, that's 8 million to 1, with the requirement that life has already started at that planet (don't know the odds of that, but as of yet we haven't found any other planet with life) and not taking into account all the species that have gone extinct (and not taking into account the risk of war, epidemics, and all the natural disasters that could wipe out a settlement of intelligent beings before it has time to develop sufficient technology for interstellar travel, or even develop technology at all).

I think we also need to consider that life, as we know it, starts in water, and that most planets just doesn't have much of a atmosphere, which leaves their planets barren but might have a underground sea (with a ice-sheet ontop, like proposed with Europa), getting to the surface in such conditions might be equal to our task of getting to space. Getting to space or even thinking of communicating to space might be a monumental problem for them, most such civilisations are probably busy exploring the surface. Also it might be fundamentally hard for sea creatures to develop limbs and other methods of actually achieving technology with, even if they would be intelligent.

Just my two cents, I think 1 or 2 per galaxy isn't such a bad estimate. Could be more intelligent life though, and even more life that's not very intelligent. I think that each step of complexity decreases the chance by a great amount.

 

i think that's a pretty fair assessment. if it is only two in this galaxy, and if the other lot aren't very close to us, then we are basically alone.

 

I think it highly likely that "intelligent" life forms at current human level, may have a half-life before self destruct, of less than 1000 years. I.e. many may have come and gone, with little probably of over lap in time.

 

Even if there's an average of one civilization per galaxy, that's still millions of civilizations.

 

From Daecon Post #16

I think one per galaxy is a serious over estimate.

The history of the earth supports the notion that life is likely to exist where ever the conditions are suitable.

It also supports the notion that technological cultures are rare with many galaxies having none & few (if any) having more than one. I posted this POV in more than one Thread. My main reasons for this POV are the following.

Above are paraphrases, not quotes: I like the quote format.

 

Even if intelligent extraterrestrials have global-warmed themselves into extinction, there should still be remnants of other life on those planets. Of course, non-intelligent life is harder to detect.

 

According to Wikipedia there's around 200-400 billion stars in the milky way, and the milky way is a pretty common galaxy. Each star can have several planets, and let's not forget the possibility that life can evolve on moons as well (where each planet typically has one or more moons), so even though the odds seem low when taking into account everything that needs to happen, I think the sheer number of sites where life can develop in each galaxy makes up for that. Some sites might also be better suited for life, so that it can develop several times, there are also very old planets where it may have developed many times. I think that once life has achieved a certain technological threshold, it is practically invulnarable to catastrophic events, I also think that they at that time no longer cares much about the outside world, as they may live forever in a computer simulation and as such no longer sends outward signals for us to detect. That's one possibility at least.

 

I don't believe we have any reason to view that as an over estimate....
While accepting the fact that with regards to ETL "we do not know", and accepting the fact that the existence of life having intelligence comparable to our own would be many values less, the sheer numbers of stars just in our own galaxy [200 to 400 billion estimates] with the stuff of life being everywhere we look, makes the claim of one per galaxy an under estimation I would think.