Talk:Fermi paradox/Archive 8

Jps's Complaints
JpS is reverting my edits, but instead of discussing here has posted his complain at the this link at the Fringe Theory Notice Board. Editors wishing to review the issue or participate must apparently go there instead of here. —GodBlessYou2 (talk) 19:39, 6 January 2015 (UTC)

Additional reference(s)
http://abyss.uoregon.edu/~js/cosmo/lectures/lec28.html

http://www.scientificamerican.com/article.cfm?id=moon-life-tides  (takes about 15 seconds to go past subscription offer)

Earth May Not Have Needed Moon for Life, Irene Klotz, Discovery News, Aug. 8, 2011.

' .  .  .  A new computational analysis, however, shows that a moonless Earth would still have swings in its tilt but the influence of Jupiter and other factors would limit the variations to about 10 degrees in either direction. . .  '

' .  .  .  "We think that at least 80 or 90 percent of planets out there statistically won't even require a moon" to have a stable climate, Barnes said [planetary scientist Jason Barnes, with the University of Idaho]. . .  '

' .  .  .  In our own solar system, Mars shows evidence of extreme climate change, the result, scientists believe, of a rotational tilt that flips between zero and 60 degrees over time. . .  '

' .  .  .  "It's a very complex problem for sure and we're not anywhere near solving it,  .  .  .  .  " Barnes said.

'The research appears in this month's Astrobiology magazine and is pending publication in the journal Icarus.'

---

http://95.76.157.166/sarm/carti/Unde_sunt_extraterestrii.pdf

The Fermi Paradox Is Neither Fermi's Nor a Paradox, Gray., R.H., Astrobiology. 2015 Feb 26

http://online.liebertpub.com/doi/abs/10.1089/ast.2014.1247

aajacksoniv (talk) 12:23, 11 March 2015 (UTC)

Section Probes, colonies, and other artifacts. Tags "citation needed" and "according to whom" in parag 5 seem inappropriate since the parag is speculative discussion and both pertinent and reasonable. — Preceding unsigned comment added by Jmostly (talk • contribs) 02:27, 17 March 2015 (UTC)

Reviewed publication on the "paradox"
"The Fermi Paradox Is Neither Fermi's Nor a Paradox." Gray Robert H. Astrobiology. March 2015, 15(3): 195-199. doi:10.1089/ast.2014.1247. Cheers, BatteryIncluded (talk) 01:56, 25 March 2015 (UTC)

Note 55
The sentence marked by cite 55 states, "A longer tidal plain would allow a bigger transitional plane for life to evolve from the ocean to land." I cannot access Researchgate to check, does the source actually say "tidal plain"? --Captain Infinity (talk) 22:41, 26 March 2015 (UTC)

Ideas that need re-inclusion.
The recent cleanup has been very helpful to the readability. However, some ideas that bear serious discussion are now not present at all in the article. In my opinion they need to be re-added with good references.
 * Complex life may be common, but intelligence is not. I've added this with references, though a pointer to the original Sagan-Mayr debate would be even better.
 * They are here undetected. Surely it is plausible that a technology good enough to cross interstellar space could observe us without our knowledge.  Needs a good reference, though.
 * They *are* here (the UFOs are aliens view). This needs mentioning since it's a common viewpoint, then followed by the evidence against it.  This contrary evidence might include the point that a significant fraction of the world population carries a fairly decent camera with them at all times.  This has resulted in many very rare incidences caught in action (plane crashes, meteors, etc) but no unambiguous evidence of UFOs. (And even if captured on camera, they are more plausibly secret military experiments rather than the products of aliens).  I have no idea were to find serious references for this.

Anyway, I think it best if the explanations are exhaustive. Even if they are bad explanations, they should be included, with discussion and references as to why they can likely be ruled out. LouScheffer (talk) 13:15, 26 June 2015 (UTC)


 * I support a short mention of the UFO extraterrestrial hypothesis and why it's not taken seriously by the scientific community. The readership will need it to understand the problem.


 * Undetected extraterrestrial artifacts in the solar system might have some very marginal weight. My sense is that some of the astronomers involved in the mainstream searches have written some things for popular audiences that imply that this may not be completely out of the question. If really good sources can be found, maybe, but caution is needed.


 * The best practice is to come up with sources before ideas, not ideas before sources. Geogene (talk) 18:03, 26 June 2015 (UTC)

OK, found a solid reference for "They are here undetected", and added it back in. LouScheffer (talk) 18:03, 27 June 2015 (UTC)

Added short section "They are here unacknowledged" with references. LouScheffer (talk) 19:22, 27 June 2015 (UTC)

Conjectures and search re alien constructs
I've changed the headings of the section about "alien constructs" to make it clear at a glance that these are topics of conjecture and search, rather than established facts. I also removed the "fiction" tag at the top of the section. I agree that WP should distinguish clearly between conjecture and established fact. However, I'm not sure that labelling conjecture as "fiction" is the best way to make this distinction. Kalidasa 777 (talk) 03:29, 29 June 2015 (UTC)

Splitting off the Explaining the paradox hypothetically section
I suggest splitting off the whole Explaining the paradox hypothetically section into "List of hypothetical explanations of the Fermi paradox". Not only does its length bloat the article by a lot; it's also missing the headers of the hypothetical arguments in the contents-box if they're properly subcategorized: here's how it should look by now (click "Show preview"). Not having these makes it impossible to link to them at other pages and also causes a lot of confusion because of the lack of structure and orientation. --Fixuture (talk) 22:03, 23 June 2015 (UTC)


 * You can link to them even if they are not listed in the table of contents. Here's an example: One argument is that humans are not listening properly. The link is built like this:  Fermi paradox.  14:54, 24 June 2015 (UTC)


 * The hypothetical explanation section is bloated because it contains substantial original research and poorly argued junk. It needs to be reduced substantially, just as the banner at the top of the article says it should be. We don't need to repeat every odd pontification about possibilities that can never be checked, even if some pontificator managed to get their ideas published in an eccentric journal or book. Isambard Kingdom (talk) 22:37, 23 June 2015 (UTC)


 * Well, maybe some sections can be shortened but that's still no help with the problem of the section headers. The hypothetical explanations for the Fermi paradox are an integral part of it that should be covered appropiately - which is to say all notable ones should be covered/indexed but so without too much detail. And there being more than a handful of them is one reason why I'd suggest splitting it off into a separate article. (There are many other comparable entries, so for example "Category:Arguments for the existence of God" which is a category of whole articles instead of a list. The Fermi paradox is about the responses to the "why" [with "they don't exist" just being one of many] and that in similar way as existentialism in its coverage [on here in general] focuses more on the different "answers" and less about the "question" that brought forward these various concepts/bookcontents/approaches/"resolutions".) --Fixuture (talk) 23:39, 23 June 2015 (UTC)
 * Well, this subject is not as notable as the existence of God! But I think a list, yes, followed by a brief explanation (like a sentence or two) together with an authoritative source citation, is sufficient. Not long tedious discussion of obvious stuff or pontification, and not citing the "50 possible solutions" book (which is goof). This could be an interesting article, but it contains far too much stuff that just diminishes the overall effect. Isambard Kingdom (talk) 23:53, 23 June 2015 (UTC)
 * Maybe I'm being overly prescriptive or restrictive or something. It would be good to get input from other editors. Isambard Kingdom (talk) 00:31, 24 June 2015 (UTC)


 * I think perhaps yes, you are being overly prescriptive or restrictive or something. While the arguments about existence of extraterrestrials may not be as notable as the arguments about existence of God, both are unresolved debates, about which there is a substantial body of literature. In this context, the Fermi paradox is important because it is a frequent argument against existence of extraterrestrials. Any detailed discussion about a question like this is going to seem "tedious" to those who consider the question insignificant... It's not that helpful to say that a particular book on the topic is "goof", because that doesn't really tell us what specifically you think is wrong with the book.Kalidasa 777 (talk) 00:22, 3 July 2015 (UTC)

I am against splitting the article, or even drastically shortening it. The topic has this structure by its very nature - there are lots of potential explanations, and little hard evidence to chose among them. Some arguments are surely stronger than others, but (a) it's not really Wikipedia's place to decide that it's junk, *provided* its published in some respectable (even if eccentric) journal, and (b) cataloging all remotely plausible explanations is helpful to the reader. You don't need to be a specialist to speculate about possible solutions (that's one of the joys of this problem), so seeing what previous folks have proposed, with references, is really helpful. LouScheffer (talk) 14:49, 24 June 2015 (UTC)


 * Well but that doesn't solve the problem with the lack of headers. They're not linkeable and it's really hard to orientate without them. I just noticed that I linked the wrong thing above. Here's what I meant to link. Click "Show preview" and see how it should look like. Splitting it off would help with that. --Fixuture (talk) 18:17, 24 June 2015 (UTC)
 * Alternatively one could set the TOC limit to a higher level, e.g.: . However by that the contents box would grow really large. I think by the count of entries a separate list would probably be more useful. Long tables-of-content are pretty standard for list-articles (example). It's just a suggestion though. --Fixuture (talk) 18:33, 24 June 2015 (UTC)

I think a paragraph for each explanation is the right size. Many explanations can't be done justice in only a sentence. On the other end, if you want a chapter for each explanation, the book is already available (and cited). LouScheffer (talk) 14:49, 24 June 2015 (UTC)

Which version of paradox is stronger?
There was a big debate here, several years ago. The observation, the two integrals, settled the debate (by showing that it cannot be settled). Since the function is unknown, which integral is bigger depends on how fast the function drops off, which cannot be said with certainty either way. All sides were willing to accept this argument, and the sentence about which version is stronger is unclear was added.

You can also state this in text form, as it depends on how fast the luminosity function declines, but this seemed more intuitive to those who are not astronomers. LouScheffer (talk) 17:59, 4 July 2015 (UTC)


 * In other words, the equation doesn't actually tell us anything? Please clarify. Isambard Kingdom (talk) 18:06, 4 July 2015 (UTC)
 * Before somebody wrote down this equation, it was unknown which version of the FP was stronger. Then somebody wrote the equation, the integral of an unknown function, and after that we still didn't know which version was stronger? Of what use is such the equation? Isambard Kingdom (talk) 18:57, 4 July 2015 (UTC)


 * To clarify why we don't know? Kalidasa 777 (talk) 00:48, 5 July 2015 (UTC)


 * It's the use of any equation - to show that there is some quantitative reasoning behind a claim, and to derive formal consequences that cannot be avoided, given an initial statement. So you claim one version of the paradox is stronger?  That means you require explicit conditions on how fast N(r) decreases as a function of r.  And how do you know that?  You don't?  Then you can't make the claim.  The math makes the reasoning explicit.  LouScheffer (talk) 12:53, 5 July 2015 (UTC)

Should (some) possible means of self-destruction be named?
Should possible means by which technical civilizations be explicitly named, or just the possibility mentioned? I think they should be named since a reader, new to the topic, might think of only of one or two - perhaps nuclear winter (the most famous). This particular worry is (seemingly) less likely than during to cold war, so the reader might assume this risk is decreasing. But in fact there are lots of other ways, some increasing in importance, and some smart people are worried about them. So I think it's worth listing a few. Perhaps limit to the few with top-rank references (this would surely include nuclear winter, climate change, physics experiments, and a few others, all of which have been covered in Nature, Science, and the New York Times, to name a few sources. LouScheffer (talk) 19:16, 4 July 2015 (UTC)
 * Physics experiments? Isambard Kingdom (talk) 19:19, 4 July 2015 (UTC)
 * Sure. The Los Alamos folks did explicit calculations on the chance of setting the entire Earth's atmosphere on fire.  This result required serious thought to rule out,, and there was clear concern about its correctnesss, (see Hamming, 1998, pp = 640–650).  Likewise people worry about accelerators creating black holes (NY Times Gauging a Collider’s Odds of Creating a Black Hole.  Same from Science, though these particular concerns have been dismissed through some more serious formal analysis.  LouScheffer (talk) 13:13, 5 July 2015 (UTC)
 * Let's be sure to avoid original research and synthesis. Isambard Kingdom (talk) 14:00, 5 July 2015 (UTC)

It is too expensive to spread physically throughout the galaxy
There were two different explanations under this heading, but only one now. These appear very different to me. The first is that it's expensive, so it happens in fits and starts, which might explain why no-one is here yet. The second is that communication is cheaper, and replaces physical travel, and is hard to see, which explains why we have not seen it.

These seem conceptually quite different, have different chapters in (for example) the 50 explanations book, and have largely different citations in the academic realm. I think they should both be included, but since I'm a cite for one of the cases, I'd like other editors to weigh in on this. LouScheffer (talk) 17:57, 5 July 2015 (UTC)


 * Right, probably good to avoid your own citations. Isambard Kingdom (talk) 18:25, 5 July 2015 (UTC)


 * The main question is whether the two explanations are distinct. There are other possible citations.  LouScheffer (talk) 18:44, 5 July 2015 (UTC)

Non-SETI astronomers studying SETI.
It's important to state that conventional astronomers (that is most of them) are NOT looking for ETs. This maybe obvious to you, but I suspect many readers have no idea what a tiny fraction of astronomers are explicitly looking for intelligent life elsewhere.

Also, precision of pulsars needs to be mentioned. Lots of astronomy stuff is very precise, but not needed intelligent intervention. Relative accuracies of 10-14 or so is what aroused interest in LGM theory. The numbers would mean little to most readers, but rivaling atomic clocks bring the point across.

Discusion welcome, as always. LouScheffer (talk) 14:50, 5 July 2015 (UTC)


 * Is it considerably likely that ETI would have already been found if all the astronomers were looking? If so, are sources available? If not, I don't see how that relates specifically to the Fermi Paradox. Likewise, I also see no relation between pulsars and the Fermi Paradox. Little Green Men would belong in an article about the discovery of pulsars, but probably not this one. Geogene (talk) 20:01, 6 July 2015 (UTC) Nevermind, I see that's already in and works just fine. Geogene (talk) 20:17, 6 July 2015 (UTC)

Name
When describing the origin story, there is the question of how much detail to include. Almost none of it is *strictly* necessary, other than Fermi saying where are they?. So the question to editors here is the right level of detail. Here are two versions preferred by different editors. If others could say which one they prefer, and optionally why, that would be great.

The shorter version


 * In 1950, while working at Los Alamos National Laboratory, Fermi had a casual conversation with colleagues Emil Konopinski, Edward Teller and Herbert York. The men discussed a recent spate of UFO reports and an Alan Dunn cartoon facetiously blaming the disappearance of municipal trashcans on marauding aliens.  The conversation shifted to other subjects, when Fermi exclaimed, Where is everybody.  Herbert York recollects that Fermi "followed up with a series of calculations on the probability of earth-like 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 such calculations that we ought to have been visited long ago and many times over."  If so, Fermi anticipated and pre-dated many of the elements that went into the Drake equation.

Alternatively


 * In 1950, while working at Los Alamos National Laboratory, Fermi had a casual conversation while walking to lunch with colleagues Emil Konopinski, Edward Teller and Herbert York. The men discussed a recent spate of UFO reports and an Alan Dunn cartoon facetiously blaming the disappearance of municipal trashcans on marauding aliens.  The conversation shifted to other subjects, until during lunch Fermi suddenly exclaimed, "Where are they?" (alternatively, "Where is everybody?").  Teller remembers, "The result of his question was general laughter because of the strange fact that in spite of Fermi's question coming from the clear blue, everybody around the table seemed to understand at once that he was talking about extraterrestrial life."  Edward Teller recalls little followup of this observation, but Herbert York recollects that Fermi then made a series of rapid calculations using estimated figures, stating that Fermi "followed up with a series of calculations on the probability of earth-like 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 such calculations that we ought to have been visited long ago and many times over."  If so, Fermi anticipated and pre-dated many of the elements that went into the Drake equation.


 * I prefer this version as the details flesh out a specific, well remembered incident that clearly made an impression on those present.  LouScheffer (talk) 03:25, 6 July 2015 (UTC)

LouScheffer, I've already made the FP story even shorter. One thing I think needs to be recognized: if people want to read an interesting story about Fermi's first thoughts on the Fermi Paradox, then they can go read the source paper by Eric Jones; we provide them with a link to the Jones paper. The text that you seem to prefer is largely copied from the Jones paper. That is not what we need in an encyclopedia. Indeed, I even think the existing text in the FP article is still too much, but I've tried to find some compromise with your wishes (yes, really). If I had my way, I'd cut that story down to a sentence and just link to the Jones paper. As I've said before, this article on the FP would benefit from a lot less clutter of stuff. The FP is an interesting issue, but it is getting lost in all that text. Isambard Kingdom (talk) 23:20, 6 July 2015 (UTC)


 * I understand that conciseness is desirable, and I've argued hard for it in other cases (see Hubble Space Telescope). But 99.99% of the readers will never click on a link, since most links just point to some boring reference that backs up some statement in the text.  If you think, as I do, that it is interesting, and you want people to click on it, then you would have to tell people that this particular link is interesting.  But if you are going to do that, you might as well tell the story - it's one easy-to-read paragraph.
 * Also, different people have different levels on interest in origin stories.  For the technical interpretation of the Fermi Paradox, it's completely irrelevant.  As Doolittle teaches the bomb in Dark Star, a concept is valid or false, no matter where it originates.  But when I gave a talk on the Fermi Paradox, the "human interest" parts of the paradox (origin, who believes/disbelieves it and why) got more interest than the technical details.  And these are the exact people who read Wikipedia for information, as the scientifically minded know it already.  So if you think in terms of what the user would like to know, as opposed to the technical details and nothing but, then the story should be included.  (This is similar to the human interest stories always included with athletic commentary, even though they have no bearing whatsoever to the action on the field.  But some fraction of people really appreciate them.)  LouScheffer (talk) 01:25, 7 July 2015 (UTC)
 * I approve of the Fermi lunch story as it stands in the current revision. Geogene (talk) 18:24, 13 July 2015 (UTC)

Current tagging.
Don't see any discussion of same so opening this thread for resolution in case it's not neurotic tagging. No idea what matter of fact is at this point but have made contributions to the article in the past (more than a y ago). Lycurgus (talk) 22:47, 13 July 2015 (UTC)

New version of Webb book out.
In May, Webb released a new version of "Where is Everybody", with 25 new explanations, and modifications of existing explanations. We'll need to tell which version of the book for any citations with chapter or page numbers, and can maybe find cites for a few more explanations. LouScheffer (talk) 10:52, 21 July 2015 (UTC)

Hypothetical explanations for the paradox
Under this heading, of course, we see the various explanations. Currently only "Few, if any, other civilizations currently exist" is ranked directly below that heading. As such, it appears in the table of contents and none of the other explanations appear there.

So I ask you:
 * Send "Few, if any, other civilizations currently exist" to the same level as the rest of the explanations.
 * Bring all the other explanations up to the same level as "Few, if any, other civilizations currently exist".

Kortoso (talk) 17:26, 29 July 2015 (UTC)

Bias towards speculation
There is at least one published hypothesis capable of resolving Fermi's paradox which does not stray from the scientific method. However, there is no mention of it here, only the usual banal speculations. When I attempted to correct this oversight, within a few minutes Geogene had (without reading the article or even its title) deleted this edit:

The mutual annihilation of gravitationally condensed neutrinos has the potential to support aquatic life well after the stars expire by internally warming iron-cored oceanic planets and maintaining liquid oceans beneath a layer of surface ice. Should dark energy decay predominantly to low energy neutrinos before stars resembling the Sun become scarce, aquatic life could be sustained for a further 1025 years. The propensity of active and sterile neutrinos to act in tandem, thermally regulating the internal temperatures of planets so as to maintain a fairly consistent heat flux through subglacial oceans may imply that the universe sparingly uses evolution by natural selection to cultivate colonists such that intelligent life is presently rare on galactic scales. This hypothesis has falsifiable implications for particle physics and thus has the distinction of abiding by the scientific method.

I suggest that Geogene withdraws the incorrect objection to its inclusion. Danrhew (talk) 17:31, 14 August 2015 (UTC)
 * I think that Danrhew should at least take up a less promotional tone towards this paper. Geogene (talk) 17:34, 14 August 2015 (UTC)


 * IMO, it is quite fringe/speculation to link dark energy decay to aquatic life, even if he managed to publish that paper. It is much more likely any planet will have thermal energy derived from its good-old star, radioactive decay or tidal heating, without having to invoke the mysterious dark energy. Besides, it is not a "solution" to the paradox, it is a speculation on energy source.  It is common for physicists to make fantastic extrapolations in biology using a single parameter of habitability, and I also struggle to keep those claims away -or at least balanced in Wikipedia.  My 2 cents. Cheers, BatteryIncluded (talk) 17:53, 14 August 2015 (UTC)
 * It certainly is not relevant here unless we have some good secondary sources linking this idea to the Fermi Paradox. ♫ SqueakBox talk contribs 22:04, 14 August 2015 (UTC)


 * The future decay of dark energy to neutrinos is not pure speculation, it is implied by the capability of neutrinos to selectively deliver energy to hcp iron in a way that regulates the thermal flux through oceans almost irrespective of planet size. See https://en.wikipedia.org/wiki/Wikipedia:What_Wikipedia_is_not#Wikipedia_is_not_censored.Danrhew (talk) 08:09, 15 August 2015 (UTC)
 * Probably not but linking this to the Fermi paradox is speculation. Wikipedia is indeed not censored so provide the reliable secondary sources linking this to Fermi andindeed we will publish. But in spite of being asked to do so once already you have made no attempt to provide said secondary sources but instead seem to think you can threaten other users to publish unsourced with your link as to wikipedia not being censored. It is not going to work, if you want it published give us the secondary sources. there is nothing else to discuss here. ♫ SqueakBox talk contribs 15:49, 15 August 2015 (UTC)
 * There is an overt connection to the Fermi paradox - which should be evident to anyone just from reading the title of the primary source. The Fermi paradox is merely a colloquial expression for the mystery of extraterrestrial silence. Therefore, no secondary source, reliable or otherwise, is required to establish that the work in question addresses the Fermi paradox. It seems more than a little hypocritical to be demanding a secondary source when (i) there is no need for one and (ii) the remainder of the material included on this page has no connection to the scientific method: much of it has not even undergone peer review. Squeakbox asked me to take a look at some information. I did and it states that "Wikipedians should never interpret the content of primary sources for themselves". Therefore, what Squeakbox or anyone else here considers plausible or implausible is unimportant. This is another friendly reminder.Danrhew (talk) 17:44, 15 August 2015 (UTC)
 * @Danrhew, According to the article, with which you seem to be familiar, the dark energy will (or might) decay into neutrinos in something like 60 Gyr, so I guess you are suggesting that this newly published theory might become relevant to a possible Fermi Paradox some 60 Gyr in the future, when it might enable possibly underwater life! Of course, the FP is not about ET life, or its energy source, per se, but, rather, why we haven't been visited by any ET. Also, of course, the FP is not about what *might* happen 60 Gyr from now, but, rather, the present circumstances. So, even if there were a secondary source citing this unusual theory, I don't see how it relevant. Isambard Kingdom (talk) 18:19, 15 August 2015 (UTC)
 * The thing with the secondary sources is they establish WP:Notability linking the idea to the fermi paradox. You certainly are correct that wikipedia should never make an interpretation of the primary source as being relevant and therefore meriting inclusion, we leave it to the secondary sources to make those connections. The fact that you are demanding that spmething is evident to wikipedia editors isnt good, we dont go by what we see as evident, we go by the secondary sources. And fermi's paradox surely concerns the reasons ET havent visited, either cos they dont exist (my belief) or because they havent, for whatever reason, been able to get here, and I am not convinced that your piece involves either, which may be why no secondary source has linked it to fermi's paradox. ♫ SqueakBox talk contribs 19:13, 15 August 2015 (UTC)
 * Isambard Kingdom - the article is relevant to the Fermi paradox, just as the title implies. It models the galactic presence of advanced civilisations as a function of past, present and future time. There would be no need to raise such trivial and invalid points if you had actually read and understood the article. Squeakbox: read your own link and you will see that section two is called "Notability guidelines do not apply to content within an article" - they are only pertinent if starting a page on a new topic. Secondary sources may be desirable when available but they are not mandatory. Nobody has yet raised a valid objection and if that remains the case then further attempts at deletion will amount to censorship.Danrhew (talk) 18:06, 16 August 2015 (UTC)

Seems we reached the end of the line, and following WP policies there is the distinct consensus to skip your assay and reference. Not promoting the fringe/synthesis does not amount to "censorship," but to responsible editing. Cheers, BatteryIncluded (talk) 21:03, 16 August 2015 (UTC)


 * I've kept out of the comments so far, but totally agree with BatteryIncluded's comments above. David J Johnson (talk) 21:54, 16 August 2015 (UTC)

Snowden
Don't know whether we can add this or not but it strikes me Edward Snowden just offered a possible explanation to Fermi's paradox, eg here Edward Snowden: we may never spot space aliens thanks to encryption Today's The Guardian. Wondering hat others think. ♫ RichardWeiss talk contribs 16:53, 19 September 2015 (UTC)
 * I don't think that Snowden has any expertise in the area, and is therefore probably irrelevant. And my OR: you can obfuscate a signal with encryption but you can't actually hide the signal. The photons don't disappear. Geogene (talk) 22:36, 19 September 2015 (UTC)
 * I would wait for a secondary source to assess Snowden's comment. Cheers, BatteryIncluded (talk) 23:33, 19 September 2015 (UTC)
 * I think it is valid as put on the context of apparently random signals, photons are everywhere, and compose the background noise we listen from space... An signal heavily encrypted, both in signal and content would be detectable? I mean, if you have only analog equipments from the 50's, you would be able to find and prove that you are receiving a signal from Sky's satellite TV, and not from any other probable source? Let's wait for the experts... Ishnigarrab (talk) 21:01, 21 September 2015 (UTC)
 * Yes, you would be able to determine the source is there, and that's all that SETI is trying to do. But I second BatteryIncluded: we need secondary sources. Geogene (talk) 21:31, 21 September 2015 (UTC)
 * Agree with BatteryIncluded secondary source required for Snowden's comment, also I don't see any expertise of the subject in his published work. David J Johnson (talk) 22:24, 21 September 2015 (UTC)
 * Yes, I agree with BatteryIncluded too. I wasn't entirely sure when I asked the question. It is also very recent, to some extent what counts is if the idea gets integrated into human culture over a period of time, i.e. did it really catch the human imagination, and of course the secondary sources, and secondary sources talking after the initial flurry, are the way we have to evaluate this. As well as evaluate ny counter-arguments such as that it would be impossible to do so, argued here, too. I am not so convinced by an "expert in the field" argument, his field certainly includes encryption, and Fermi's paradox strikes me as a broad and not a narrow topic, you don't need to be a cosmologist or a biologist to answer the question "where are all the aliens?", people from a whole range of interests have tried to answer Fermi's paradox. ♫ RichardWeiss talk contribs 02:14, 22 September 2015 (UTC)
 * There is lots of stuff reported in the popular press, with some person saying this or that thing. The comment by Snowden is an example of that. While amusing, it does not rise to the level of needing to be included in this article on the FP. Isambard Kingdom (talk) 05:59, 22 September 2015 (UTC)
 * I know this is not the place to comment on this, but it I was to quote a geek on the Fermi Paradox, I'd go first for Elon Musk: . Cheers,  BatteryIncluded (talk) 17:13, 22 September 2015 (UTC)
 * Steganography would be more relevant - Gonioul (talk) 20:31, 4 October 2015 (UTC)

So my Snowden edit was deleted. You're right that he's not an expert in astronomy, but he is an expert in encryption which is what makes his idea so interesting. SETI isn't just looking for streams of photons; a signal has to meet certain criteria, such as repetition, the presence of metatdata, etc. to be a candidate for intelligent life. Encryption flattens these markers out via randomization to the point where the signal just looks like noise. As for notability, these explanations are necessarily speculative so it's difficult to rank, but the fact that several articles reported on Snowden's idea seems to me to make it notable as a hypothesis. Unbesorgt (talk) 17:59, 21 October 2015 (UTC)
 * The issue is a complicated one that involves some astronomy but mostly information theory. Snowden's remarks were widely reported by media, but with little interpretation. Will this change the way the Fermi paradox is discussed by astronomers? So far no evidence of that. I think the policy that best applies for now is WP:NOTNEWS. If astronomers do start talking about it in a significant way, we'll have to include it. Geogene (talk) 18:42, 21 October 2015 (UTC)
 * That's true as far as it goes, but I'd argue the Fermi paradox has relevance to more people than just astronomers (and information theorists, as you note). It has profound philosophical implications, which thanks to both popular science and science fiction have become known to millions of lay people.  Wikipedia is not a newspaper but neither is it a scientific journal.  In fact one way people end up debating ideas like Snowden's is by exposure to them on web sites like Wikipedia, where hard science intersects with a more generalist approach to knowledge. Especially on a subject as speculative as this one, I'm having a hard time understanding why this theory is verboten while a vague explanation like "Human beings have not existed long enough" is allowed to stand without a single citation. Do people simply dislike Snowden's politics so much that original research is preferable to his expert opinion as a cryptanalyst? Unbesorgt (talk) 23:28, 21 October 2015 (UTC)
 * Wikipedia does not have to include everything every famous people think. Snowden is famous for stealing sensitive government information at his job OR as a benign whistleblower, not famous for cosmology, astrobiology, SETI, or even IT. BatteryIncluded (talk) 23:39, 21 October 2015 (UTC)
 * Snowden is an expert in the fields of IT and encryption, which is what makes his theory on the implications of encryption of information for SETI relevant. Just because he is famous for other reasons does not mean he is not also an expert in his chosen field, having worked in that capacity for sub-contractors of the NSA, CIA and other government agencies.  This isn't Taylor Swift we're talking about (and I doubt Neil DeGrasse-Tyson would have been interviewing him for StarTalk if it were). Unbesorgt (talk) 23:55, 21 October 2015 (UTC)
 * Snowden is not an expert on FP. Thank you, Isambard Kingdom (talk) 00:02, 22 October 2015 (UTC)
 * Fermi's paradox is a very broad topic. It's not the kind of thing you get a degree in and became the noted authority. The people quoted elsewhere in the article are cosmologists, physicists, science popularizers, etc. Information theory and encryption certainly touch on it as well. Unbesorgt (talk) 00:15, 22 October 2015 (UTC)

Another take
Source: Most Earth-Like Worlds Have Yet to Be Born, According to Theoretical Study

Reports on this upcoming paper: -Cheers, BatteryIncluded (talk) 15:17, 28 October 2015 (UTC)
 * Earth Bloomed Early: A Fermi Paradox Solution? Space.com
 * Most earth-like worlds have yet to be born, according to theoretical study

Main points in lead paragraph or overview?
I think the main points (the bulleted ones) belong in the lead paragraph (the lede) and not the overview. This makes no difference to the argument, but ensures the main points appear on the initial screen when someone looks at the page. If they are in the overview, the reader may need to scroll down to see them, particularly on a laptop or a tablet. Putting the main points in the leded will help the casual reader (who often reads only the lead paragraph), and does not hurt the serious reader. LouScheffer (talk) 15:41, 23 January 2016 (UTC)
 * Moving the main points down to overview was an edit made by : . And I think his/her change is fine. Isambard Kingdom (talk) 15:49, 23 January 2016 (UTC)


 * Relevent parts from Manual of Style/Lead section: "The lead is the first part of the article that most people will read. For many, it may be the only section that they read." and "The lead should stand on its own as a concise overview of the article's topic.".  I think putting the main points in the lede helps both these points.  It is certainly not too long - "As a general rule of thumb, a lead section should contain no more than four well-composed paragraphs and be carefully sourced as appropriate."  LouScheffer (talk) 15:52, 23 January 2016 (UTC)
 * On the mobile version of Wikipedia, as you see from your cell phone, the lede appears directly, but the overview requires an extra click to expand. LouScheffer (talk) 16:11, 23 January 2016 (UTC)


 * Hello. According to WP:LEAD, the introduction must be a summary (a readable prose), not a list of the article ideas.  And: "Apart from basic facts, significant information should not appear in the lead if it is not covered in the remainder of the article."  This means that if you add that list to the introduction, you have to repeat it in the Overview, which is an overkill and makes the format kind of awkward. Cheers, BatteryIncluded (talk) 17:45, 23 January 2016 (UTC)


 * Hi, I cannot find anything in WP:LEAD that says it must be prose. And in this case, the list seems visually appropriate, since the 4 ideas must be combined to reach the conclusion.  If presented in a linear order it takes more memory and concentration to see this.   Also, what idea is in the lead that is not mentioned in the article?  Why would the list need to be repeated in the overview?  (Agree that presenting it twice would be overkill, but it's not needed IMO).   LouScheffer (talk) 18:40, 23 January 2016 (UTC)


 * If you can convert the list to prose that introduces the points in a manner equally easy to read, I have no problem with that. But the ideas should stay in the lede.  LouScheffer (talk) 18:48, 23 January 2016 (UTC)

Also, without the list (or it's equivalent) the lede is much too short by the usual Wikipedia standards. For an article of this length, WP:LEAD recommends a 3-4 paragraph lede. One short (two sentence) paragraph cannot provide enough of an intro, IMO. 18:48, 23 January 2016 (UTC)

Finding planets or finding data glitches
With so many extrasolar small planet discoveries being announced it turns out the one closest to us at Alpha Centauri was a data blip

As insinuated in the following article others detected further away may also be data blips. While detecting Jovians and Super Jovians may be fairly easy these days, detecting earth sized bodies is bleeding edge, and someone just cut their fingers.

Per my googling, something like 30% of nearby stars are metal rich Population I stars so it would not be in the least surprising to find earth sized bodies. However for the galaxy as a whole the number of Population I stars is a measly 2%.

http://www.popularmechanics.com/space/a18003/no-alpha-centauri-b-planet/

This doesn't rule out planets around the stars in the Alpha Centauri system, it simply means it rules out this planet. So now, it's back to the drawing board. So congratulations, Gliese 15Ab, you are now the closest planet to Earth at 11 light years away. Just don't go squandering it by also being an observational error.

71.174.135.36 (talk) 23:21, 2 February 2016 (UTC)


 * You seem to be talking about content that could appear in an article different from this one. Isambard Kingdom (talk) 23:44, 2 February 2016 (UTC)


 * Not thinking of adding this since it is way too fuzzy, but how many earth type planets exist out there is part of the Drake equation and therefore Fermis paradox. One so called "earth type waterworld" is actually more like super furnace hellworld with a temerature of 1,700 and an atmosphere of superheated steam. When I heart earth type waterworld I'd like to see some wet type water.71.174.135.36 (talk) 00:31, 3 February 2016 (UTC)

tried to add material on some factors of the Drake equation
which keeps getting deleted.

If people bother to even read the article they would notice that according to some (Tipler) the Drake equation yields less then 1 technological civilization per GALAXY while other came up with mega millions. Meanwhile this article is infested with material such as the Earth is a ZOO. Get real people.

To put in in easy to understand language. If you look and can't find, it's either not there, it's hiding. or you are not looking hard enough. 71.174.135.36 (talk) 16:27, 2 February 2016 (UTC)

How many stars have the qualities to form an earth type planet. My guesstimate based on the what I have come across.

The star should be either a G or K type star roughly 10% of all stars

Ideally it should be a solitary star but can be a member of a binary or higher system far from the other member(s) - call it 30%.

It should be an a population I star (metal rich) about 2%

It should be old enough for tech civilization to develop - call it 20%(the sun is one of the older Pop I stars and is considered metal rich even among Pop I stars)

It should have a stable orbit around the galaxy - around 5%

Number of qualified stars = (.1 or 10%)(.3 or 30%)(.02 or 2%)(.2 or 20%)(.05 or 5%)=.0000006.

This comes to roughly 1 in 165,000 stars have the necessary qualifications to form a earth type planet on which life has had enough time to evolve. Whether an earth type planet did form, whether life emerged on that planet or higher intelligent life evolved are other factors in the Drake equation.

Thank you 2 semesters of astronomy!71.174.135.36 (talk) 17:03, 2 February 2016 (UTC)


 * Not saying it is false or incorrect. Saying that you need to cite a reliable source that states what you are entering. You keep adding a bunch of unrelated references to make an argument; that is WP:OR and WP:Synthesis. Please read these 2 links. Thank you. BatteryIncluded (talk) 17:42, 2 February 2016 (UTC)


 * Exactly what do you need a cite for? The article itself states that according to Tipler the number of civilizations may be less then 1 per Galaxy. The cites I am using are either one discussing the Drake equation, basic astronomy, or how life developed on earth. As many, who have tried to work up numbers for the Drake equation, have stated, "when it comes to how life developed and what are the conditions for evolution we have a sample size of exactly one". 71.174.135.36 (talk) 18:19, 2 February 2016 (UTC)


 * BTW: I am 100% certain that the above calculation is wrong since it is based on incomplete, and probably faulty knowledge. Then again so is everyone else's!71.174.135.36 (talk) 18:33, 2 February 2016 (UTC)


 * RE:OR - People stating that the assumption used in the Drake equations are not that rare, so this can't be OR. How the hell can it be OR anyway? I mean what Original proposition am I pushing?


 * RE:Synthesis - I attempted to find reasons why the Drake equations may be optimist. All the reasons are unlikely to be in one place so I looked all over. This is no different then the 20 reasons already listed on why we have not discovered alien civilizations, which also did not originate from the same source and are a compilation. One example of those 20 being "The earth is a Zoo". If the earth is a zoo and the other 19 compiled reasons are not synthesis, then why is my compilation synthesis? Both lists were compiled in the same manner. Please advise!71.174.135.36 (talk) 19:16, 2 February 2016 (UTC)


 * In case people missed it I have added a cite where Drake himself admits that numbers plugged into his equation are at times optimistic. Currently cite 107 from Sky and Telescope.71.174.135.36 (talk) 23:25, 2 February 2016 (UTC)

How about shifting most of this content over to Drake equation? A short summary at Fermi paradox might be sufficient. Just suggesting. Isambard Kingdom (talk) 23:42, 2 February 2016 (UTC)


 * Don't object except I dread dealing with more "know it all" wiki editors with OR, synthesis and other complaints. I wish that Earth is a Zoo section was changed to earth is a reservation/life preserve or something buts its unlikely to happen. It's about as demeaning as you can get.71.174.135.36 (talk) 00:16, 3 February 2016 (UTC)
 * Best to refrain from too much complaining about editors, and, instead, try (as much as possible) to stick to discussing content. Just saying. Isambard Kingdom (talk) 00:21, 3 February 2016 (UTC)


 * I had to google a few of the cites 3 times yesterday because the added material got deleted so fast I go an edit conflict when I tried to post the cites. Not happy in the least!71.174.135.36 (talk) 00:55, 3 February 2016 (UTC)
 * I've tried to clean things up. Isambard Kingdom (talk) 02:40, 3 February 2016 (UTC)

Empirical projects
This section seems to be about SETI, not so much about the Fermi paradox, which is a paradox of why we haven't been visited by aliens or found any evidence of their existence. I suggest that this section, which is possibly OR trying to be relevant to FP, either be removed, as not directly relevant, or substantially reduced in volume. Isambard Kingdom (talk) 14:11, 4 February 2016 (UTC)


 * I think most of the sub-sections are relevant, since the part of the paradox "We see no evidence" immediately implies the question "what have we looked for?". The one section that seems un-connected in this was is "Direct Planetary Observation", since for the purpose of the paradox we don't care how they were detected, just that they exist in respectable numbers.   If this was instead something like "Evidence that planets are common", and summarized exo-planet detection and statistics, then it would apply directly to the paradox.   LouScheffer (talk) 16:37, 4 February 2016 (UTC)


 * Infomation panspermia section could go too, IMO. LouScheffer (talk) 21:14, 4 February 2016 (UTC)
 * Yes, I followed the links and refs and it seems quite fringe. BatteryIncluded (talk) 04:49, 5 February 2016 (UTC)

Advanced civilizations tend to cause overcrowding
The overcrowding hypothesis is not original research as mentioned in this NIMH published article. Or the section should be called sub-replacement fertility instead of overcrowding.

http://tomax7.com/HeyGod/misc/MousePopulationStudy.PDF

Also the primary sources of antiquity support a sub-replacement fertility in those civilizations that were highly urbanized.

http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0234%3Abook%3D37%3Achapter%3D9

https://books.google.co.uk/books?id=JdGQNIxBMh0C&redir_esc=y

Demographic-economic paradox also supports this theory as the richer nations are highly urbanized

For advanced civilizations to arise an intelligent species must gather in high-density sedentary urban centers such as cities or villages which would enable task specialization and allow individuals to focus on technological advancement, leading to increased industrialization and development. This phenomenon has been observed throughout the history of the World and has been seen to transform agrarian societies into industrial ones. The benefits of urban life have led to increasing levels of economic and technological growth which have enabled humanity to begin space exploration, and become a civilization close to attaining a Type I classification on the Kardashev scale. And according to future predictions the percentage of people living in urban centers will continue to rise. However increasing development associated with urbanization causes other effects as well, such as lowered fertility which can be seen in the demographic-economic paradox. According to the studies John B Calhoun and using the theory of the Behavioral Sink as a species spends more time living in high-density overcrowded conditions the fertility rate should decrease over a generational period of time. The study suggests that individuals who have evolved in low-density conditions are socially unprepared for life in high-density conditions. The violation of the Dunbar number seems to have consequences that may decrease the fertility of a group over time. Also many Ancient civilizations who have lived under high-density conditions such as the highly urbanized Ancient Greeks and Ancient Romans seemed to have suffered rapid depopulation at the end of their existence which can be found in the archaeological evidence of Late Antiquity. The Greek Polybius describes the dearth of children that he observed in Ancient Greece. And Cassius Dio a historian who lived in Ancient Rome documented the low birth rates that were affecting the Roman nobility. Low-density nations who lived close to these civilizations eventually took over their territory as is usually described by the Barbarian invasions. Also between 1206 and 1150 BC, the cultural collapse of the Mycenaean kingdoms, the Hittite Empire in Anatolia and Syria,[1] and the New Kingdom of Egypt during the Bronze Age Collapse can be attributed to sub replacement fertility rates due to overcrowding in those civilizations. The fairly rapid depopulation and abandonment of most cities in those civilizations can be attributed to low fertility rates. Further back the urban Minoan and Sumerian civilizations were also depopulated, and their territory was later taken over by people who lived under low density conditions that lived nearby. Promet14 (talk) 05:13, 17 February 2016 (UTC)


 * In Wikipedia, this is what we call WP:OR and WP:SYNTHESIS. What you need is a reliable source that explains this hypothesis as an explanation for the Fermi paradox on extraterrestrials. Cheers, BatteryIncluded (talk) 07:34, 17 February 2016 (UTC)

Exeternal links candidate
Are blog posts ever listed in the external links section? I found the following blog post highly logical, although written in colloquial language. http://waitbutwhy.com/2014/05/fermi-paradox.html70.127.87.143 (talk) 15:51, 26 March 2016 (UTC)Nathan

Synthesis tag
I've been watching from the sidelines; If Fermi's paradox is asking "where is everybody?" I think it is quite appropriate to list the proposed hypotheses on where they are. Having said that, I think the article needs some trimming of synthesis, all of SETI, and non-notable speculations. Cheers, BatteryIncluded (talk) 01:54, 28 March 2016 (UTC)


 * Agree about synthesis and not-notable (although in my experience, almost every hypothesis has at least some reputable source, so non-notable may be hard). But I think this needs to be tackled on a section by section basis.   SETI, I think, is useful as far as it is an empirical attempt to settle the hypothesis - maybe for the purposes here, a pointer to the SETI page, stating that a large number of methods have been tried, but found nothing yet, though none of the tried methods are exhaustive.  These SETI non-findings need to be explained, as well as the not-observed aliens here, and the not-observed aliens by astronomers.  LouScheffer (talk) 03:12, 28 March 2016 (UTC)


 * I have found references for all "citation needed" or removed the material. Where possible, I tried to put a quote in the citation to support the references.  So if you examine a reference, and it does support the article, you could consider adding a quote as well.  As always, feel free to add back CN, OR, or SYNTHESIS tags if you find the references, when considered in detail, do not support the statements in the article.  LouScheffer (talk) 18:22, 31 March 2016 (UTC)

Possible OR or at least subject creep
I inserted a "citation needed" flag regarding the issue of whether or not the Fermi paradox (FP-Hart) can be asked in two ways, but removed this flag with this edit:. Right now the article asserts that FP-Hart has two parts or questions: 1. Why are no aliens or their artifacts found here on Earth, or in the Solar System?, and 2. Why do we see no signs of intelligence elsewhere in the universe? I am wondering whether or not these "two ways" amounts to an expansion of FP-Hart from its original focus as stated by Fermi and Hart. So, it seems that Fermi didn't write an article about FP-Hart, but the article recounts a story in the section entitled "Name", and that seems to only be about question 1, why there are no aliens on Earth -- not about us actually undertaking a "search for extraterrestrial intelligence" and finding it somewhere in some way. Also, when I look at Hart's paper, that also seems to only be about question 1 (what Hart calls "Fact A" not about SETI per se). Therefore, I am wondering whether or not Wikieditors have possibly over interpreted FP-Hart and included question 2 in the mix and, also, material about SETI when that is (as far as I can see) not what FP-Hart is about. Just trying to keep this article focussed. Thank you, Isambard Kingdom (talk) 22:01, 6 February 2016 (UTC)
 * I have no idea about the distinct vs overlapping or core+expanded relationship here. Mine was just a plain-language concern, that if we have two things described as the first and second ways and each is cited, then "we have two ways...way 1 with cite...way 2 with cite" doesn't seem to require an additional cite for the "we have two ways" lead-in. If there is some other relationship, then the description of the second idea should explain that relationship and the topic sentence should reflect whatever it is. DMacks (talk) 22:07, 6 February 2016 (UTC)
 * That's fine,, I appreciate your explanation, and I'm just providing mine. We already have a pretty good SETI article, and this on FP-Hart, might not need to have so much overlap with it. Hence, my question. Isambard Kingdom (talk) 22:11, 6 February 2016 (UTC)
 * I agree Hart (at least the early paper) was explicitly concerned with the lack of aliens or probes physically visiting Earth. I don't think there is any evidence for exactly what Fermi was thinking, which could have been either (no evidence from astronomy, no evidence of physical visits, or both).  Certainly very early in discussion the more general form as used, as in Brin 1983, where he refers to "The apparent absence of evidence for extraterrestrial civilizations" and talks explicitly of both forms.  Certainly in the popular mind, the absence of SETI detections weighs into the Fermi paradox, as in this NY Times article.   And in less formal blogs, you can find folks talking about the impact of Kepler, or Tabby's star, on the Fermi paradox, even though there is no chance any discovered aliens will visit Earth anytime soon.  Finally, if you asked a hundred scientists what you call the contradiction between lots of planets and no detections of life elsewhere, I'll bet all hundred will call it the Fermi Paradox. Not a single one would say "That's an unnamed paradox closely related to the Fermi Paradox, which only deals with aliens or artifacts on Earth."  Overall, both forms are overwhelmingly consistent with modern usage.   LouScheffer (talk) 00:33, 7 February 2016 (UTC)
 * Okay, I understand there has been confusion on this issue. Do we have, say, a scholarly source the supports FP-Hart being about SETI?
 * The Brin 1983 article discusses Hart, Tipler, etc. as its basis (Fermi's account was only oral history at that time), and includes the SETI stuff.  It has quite a few cites to it (135), not too far from the number for Hart (190).  So I think the combo is pretty well established in the literature.  LouScheffer (talk) 01:08, 7 February 2016 (UTC)
 * Brin (1983) is about more than just FP-Hart, and that Brin (1938) has citation does not make it relevant to this point. The story recounted by Eric Jones about Fermi's conversation, and the defining article by Hart, are specifically about why we don't have extraterrestrials on Earth right now. They are not about SETI per se. Of course I can find articles that mix discussion of FP-Hart with SETI, but that would not be an objective search of the literature. We have, here, a problem of article creep, and it needs to be corrected, otherwise the essence of FP-Hart ends up getting obscured. Isambard Kingdom (talk) 15:03, 7 February 2016 (UTC)
 * I agree there is creep, but it's in the scope of the science, which is merely echoed in the article. When people refer to the Fermi Paradox *now*, they include both problems (they are not here, and we see no evidence), as shown by the references above.  Especially for a source intended for casual perusal (such as Wikipedia) we should follow this shift.  We might mention that historically, Hart (and maybe Fermi) were only concerned with ETs on Earth.  This type of expansion is common in science - people refer to "Darwin's theory of evolution" even when talking about aspects unknown to Darwin.   LouScheffer (talk) 15:36, 7 February 2016 (UTC)
 * Since Fermi never himself defined the paradox, we don't know for certain if he meant only "no evidence of visits" or "no evidence in general". However, Teller (who was part of this conversation) recalls: "The discussion had nothing to do with astronomy, or with extraterrestrial beings.  I think it was some down to Earth topic.  Then, in the middle of this conversation, Fermi came out with the quite unexpected question 'Where is everybody?' ".  Following this reasoning, if they had been discussing astronomy Fermi's question would not be surprising, and if so likely it at least includes evidence as well as visits.  Furthermore, we know from this account, referring to the pre-history of the Fermi Paradox that "Philip  Morrison pointed out that project scientists, in a burst of black humor, sometimes referred to supernovae as failed fission/fusion projects by extraterrestrials."  From this we know the "project scientists", presumably including Fermi, had thought about the signatures of intelligence as seen by astronomers.   This evidence is all very indirect, but to me at least makes it more likely than not that Fermi was referring to all kinds of evidence, not just visits.  At any rate concluding that Fermi ONLY was referring to visits, when he had previously discussed signatures, seems a stretch.


 * And in any case, when referring to the Fermi Paradox *now*, in the both observations and visits are surely included. For example, in "If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Seventy-Five Solutions to the Fermi Paradox" Webb says "If the colonization of the Galaxy could take place [...] one would expect one or more of the advanced technological civilizations to have long since completed the job.  Even if they all took some path other than colonization, shouldn't we at least expect to hear some evidence of their presence? [...] Surely Fermi's question is worth some of our attention".  Likewise in "Fermi's Paradox, Cosmology and Life" we find "Fermi’s paradox relates to this finding, but in its original form, was posed as a question, as to why, in a universe such as this, we have no knowledge of the extraterrestrial life which should be common."  Similarly in "Is Anybody Out There", we see "sixty years after that otherwise ordinary lunch [..]  attempts to answer it directly, by searching for signals from extraterrestrial civilizations or signs of stellar engineering...".


 * So including both "no visits" and "no evidence" matches current usage, and is certainly the least surprising, and most helpful, to the reader. LouScheffer (talk) 03:58, 3 April 2016 (UTC)

Silentium Universi
I think this should be included. My arguments are:
 * It's mentioned in common with the Fermi Paradox about as often as "The Great Silence" (Google, admitedly imperfect, shows about 3600 mentions of "Silentium Universi" along with Fermi, and 700 more for the mis-spelling Silencium, and about 4400 for "the Great Silence" along with Fermi.) If you include one you should include the other.
 * The page Silentium universi redirects to Fermi Paradox. Since it appears almost nowhere else in Wikipedia, there is no other page for it to reasonably re-direct to.  So if you remove it from here, that page should be deleted as well.   But it's used enough that an entry seems reasonable.  (The Great Silence also links to Fermi Paradox indirectly through the header, since there is a movie of that name.)
 * Google scholar shows quite a few references to the page in Russian papers that appear (via google translate) to be on-topic. It would be great if a fluent reader of Russian could check these references out (and I'm sure there are many Russian references that should be added to the page in general).

From a philosophical point of view of Wikipedia, editors can vary on how related concept should be treated in an article. If the related subject has an article of its own, then a link to a full page is great, as in Drake Equation from Fermi Paradox. But if it does not, as in "Silentium Universi", then a single sentence (with reference) is much better than nothing. When I read a Wikipedia article, it's usually since I know little about the subject, and often my initial search is slightly off the final topic that I need. So I find the inclusion of related concepts extremely useful. I'd be very interested to know what other editors think about this. LouScheffer (talk) 17:59, 3 April 2016 (UTC)

Should lede mention alternative names?
Should either or both of the alternative names Fermi-Hart paradox or Hart-Tipler argument be mentioned in the lede? The sources I have cited in the Name section argue that these names are preferrable since (they argue) Hart's, and possibly also Tipler's, contributions to this idea are more substantial than those of Fermi. SJK (talk) 11:30, 12 June 2016 (UTC)

Resurrected argument on expense of physically colonizing
Resurrecting an argument that got deleted in this section. The main reference on this is my own work. WP:SELFCITE specifically says this is OK if it is otherwise suitable. I believe it fits this section, is not already covered, and seems reasonably notable. It's cited or described in: See Scheffer for an earlier and thorough defense of the notion that "information transfer" is a much cheaper option for interstellar travel than physical travel. Scheffer resolves the Fermi Paradox by arguing that the first civilization to colonize the galaxy will have done all the hard work; for any emerging society it will be overwhelmingly attractive to join the existing civilization rather than try to physically colonize the galaxy.
 * Formal scientific papers: here, here, and here.
 * Less formal: The Great Filter, full version here. Not published in a peer reviewed format, but well cited in Google Scholar.
 * Popular science books. google book link to text.   See also,  link to passage in Google books.  A passage from this could serve as a summary:
 * Science fiction: 3001: The Final Odyssey, a novel by Arthur C. Clarke. Google book text is here.

Other opinions are welcome, LouScheffer (talk) 21:59, 2 November 2016 (UTC)


 * This idea of mind uploading as a form of communication ... isn't this fringe? Also, FP is about why we haven't been visited, not dreaming up new means of communication, which would seem to apply more to the Drake equation than to FP. Why not just put your stuff on the mind uploading page, rather than introduce your original research here? Thanks. Isambard Kingdom (talk) 22:18, 2 November 2016 (UTC)


 * At least 3 sources think this hypothesis bears directly on the Fermi Paradox, even the physical form (and I'm not at all sure Fermi meant *only* the lack of visits, and not also the lack of evidence) LouScheffer (talk) 23:38, 2 November 2016 (UTC)
 * Webb: "Scheffer resolves the Fermi Paradox..."
 * Lamb: "So how does Scheffer's thought experiment resolve the Fermi Paradox?  Teleportation eliminates the need for physical systems of transport and colonization, so they are not likely to be here in any physical sense..."
 * Clarke, discussing this hypothesis: "the present lack of interstellar tourists is simply due to the fact that no receiving equipment has yet been set up on Earth.
 * That your idea got cited 17 times (according to Google) is not that impressive. Isambard Kingdom (talk) 23:52, 2 November 2016 (UTC)Isambard Kingdom (talk) 10:49, 3 November 2016 (UTC)


 * I think there's an implicit assumption in the argument that if ETI is motivated to expand by a desire to learn, then learning by advanced communication would reduce ETI's tendency to expand and lower the likelihood of detection. That's where the Fermi Paradox comes in. If I'm correct, should that be made explicit where it's presented in the article? I'm not sure if it's disproportionately Fringe for this particular article to say that someone with the right technology could probably write programs that imitate thought, just as it's reasonable to assume that someone out there could manage interstellar space flight. "Mind uploading" does carry some questionable metaphysical baggage about who or what actually wakes up in the machine, but I don't think Scheffer (1994) is demanding that. I'm not worried about SELFCITE here. Geogene (talk) 00:10, 3 November 2016 (UTC)
 * I see, now I understand Scheffer's paper. Isambard Kingdom (talk) 00:32, 3 November 2016 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified 3 external links on Fermi paradox. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Corrected formatting/usage for http://www.space.com/scienceastronomy/alien_intelligence_021202.html
 * Added archive https://web.archive.org/web/20101008120426/http://exoplanet.eu/papers/udry_terre_HARPS-1.pdf to http://exoplanet.eu/papers/udry_terre_HARPS-1.pdf
 * Added archive https://web.archive.org/web/20090523030456/https://www.space.com/searchforlife/seti_decode_011115.html to http://www.space.com/searchforlife/seti_decode_011115.html

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 01:30, 12 May 2017 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified one external link on Fermi paradox. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20140811194232/http://event.arc.nasa.gov/main/home/reports/CP2007-214567_Langhoff.pdf to http://event.arc.nasa.gov/main/home/reports/CP2007-214567_Langhoff.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 05:03, 20 May 2017 (UTC)

Making signals pseudorandom as a means of avoiding detection (encryption and compression)
You can't make a signal disappear by encrypting it or compressing it, or using a weird modulation. It's still there in the receiver, crowding out the background noise. You don't need to demodulate it to know it's there. On Earth, you can do sneaky things with spectrum hopping, but I have reason to suspect that would be inconvenient over interstellar distances. There are some types of digital signal modes that can greatly reduce the transmitter power you need to achieve a communication, but at the same time you must pay for that reduction in power with a lot of redundancy built into the transmission, and this will kill your bandwidth, because there are no free lunches in information theory just as there are none in thermodynamics. Now, I'm not an astronomer and I don't know much about information theory, but I have to insist on there being sources for this before the article says otherwise, because terrestrial radio just doesn't work way. Geogene (talk) 21:41, 5 July 2017 (UTC)


 * I think you are missing the point. The theory isn't that encryption or compression would cause the signal to somehow magically "dissapear." The idea is that such a process would cause the signal to appear sufficiently random, that SETI would fail to discern any pattern that would distinguish the signal from the noise of naturally-occurring radiation. No laws of physics are being violated here. Unbesorgt (talk) 01:38, 13 August 2017 (UTC)


 * That's not how radio works. The signal is obviously present, regardless of whether you can make sense of it or not. "Randomness" is not a meaningful measure of signal intensity at the receiver. While a pseudorandom signal might superficially resemble noise, radio astronomers are keen to catalog and account for the origin of all such noise sources, so it's not like this would make a new or anomalous source just fall through the cracks. I suppose one could argue that the existing catalog of sources might contain technological signals that have been misattributed to natural origins, but that's not a testable assertion. Geogene (talk) 02:06, 13 August 2017 (UTC)

It's odd that the explanations section doesn't include the most simple explanation
"We just got unlucky". Even if the probability is high, we might just got unlucky. --188.4.51.15 (talk) 01:13, 7 October 2017 (UTC)

Would this fall under any of the listed possible explanations?
When reading the possible explanations, it occurred to me that none of them (at least not obviously) consider the possibility that we might be one of the first intelligent life forms in the universe. I.E. There will be others, at some point, but not just yet. It seems we're always searching for signs of a civilization that would've been "out there" in the past, as if searching for the "ancients", but we're not actually considering the possibility that the "ancients", one of the first civilizations to reach for the stars, might be us. -jan.maska@gmail.com 104.129.194.157 (talk) 18:08, 13 December 2017 (UTC)
 * You could well be right, but considering the age of the Milky Way galaxy I doubt it. Personally, I do not consider it is worth adding these views to the article, as they are covered already; although I'm happy to accept consensus. Regards, David J Johnson (talk) 20:56, 13 December 2017 (UTC)
 * It all comes down to citing a reliable/relevant reference. Cheers, BatteryIncluded (talk) 22:16, 13 December 2017 (UTC)

Inflation hypothesis and the youngness argument
Perhaps I am misunderstanding this argument, but wouldn't a natural corollary be that any self-aware observer would most certainly be the first self-aware observer to develop in any given universe? Which would mean

A) I am the only truly self-aware structure in the Universe and posting this here in an attempt to communicate with other minds is as futile as any such attempt I have had / will have.

B) The 10^whatever chance that we are all living in a Universe than has had billions of other observers develop

C) This explanation is incorrect. — Preceding unsigned comment added by 73.169.162.99 (talk) 12:16, 20 March 2018 (UTC)

Adding Information to "Periodic extinction by natural events" Paragraph Semi-protected edit request on 25 June 2018
Dear Respective Editing User, Please add requested information at end of the following paragraph: ORIGINAL PARAGRAPH BEGIN
 * Yes check.svg Done L293D (☎ • ✎) 15:04, 25 June 2018 (UTC)

Periodic extinction by natural events
New life might commonly die out due to runaway heating or cooling on their fledgling planets. On Earth, there have been numerous major extinction events that destroyed the majority of complex species alive at the time; the extinction of the dinosaurs is the best known example. These are thought to have been caused by events such as impact from a large meteorite, massive volcanic eruptions, or astronomical events such as gamma-ray bursts. It may be the case that such extinction events are common throughout the universe and periodically destroy intelligent life, or at least its civilizations, before the species is able to develop the technology to communicate with other species. END with newly specified information, in the following fashion: UPDATED PARAGRAPH BEGIN

Periodic extinction by natural events
New life might commonly die out due to runaway heating or cooling on their fledgling planets. On Earth, there have been numerous major extinction events that destroyed the majority of complex species alive at the time; the extinction of the dinosaurs is the best known example. These are thought to have been caused by events such as impact from a large meteorite, massive volcanic eruptions, or astronomical events such as gamma-ray bursts. It may be the case that such extinction events are common throughout the universe and periodically destroy intelligent life, or at least its civilizations, before the species is able to develop the technology to communicate with other species. Another aspect is the development of coherent means for sentinel information beyond periodic extinction, e.g. the Arecibo message. Problems with the Arecibo message arise with the fact that the species it's aiming for might not look like the picture it's portraying and even more so, beyond assumptions for natural evolution and civilization advancement, the hands it falls into offer the chance towards foreign species being not much acquainted to humans in the life stage at the time (whether or not evolved or unevolved humans' interaction presence) and even be part of another aspect of aimed aliens' existence such as their food-chain, e.g. dinosaurs (despite somewhat out of the line of our evolution) capturing an artifact not encompassing major odds (provided no abrupt event for drastic developmental information seizure occurred, hence leading to intrinsic repercussions and even greater paradox to Fermi's encounter points) thus who knows what the consequences of the message might be. END Thank you for fulfilling this.

with Best Regards,

ivs5982 Ivs5982 (talk) 13:11, 25 June 2018 (UTC)


 * I've reverted the addition because it was unsourced, and because it appears indistinguishable from the "they are too alien" argument already in the article. Geogene (talk) 16:28, 25 June 2018 (UTC)
 * I agree with the deletion. I was going to reply here earlier today that it is a lot of words for "aliens can be dangerous, too advanced for us to communicate, and unpredictable." I'm sure all that is already included under some sections. Besides, the Arrecibo message has an extremely limited direction and range in astronomical scales. Cheers, Rowan Forest (talk) 00:34, 26 June 2018 (UTC)

Incorrect Linking Fix
Hi, I was reading the "Extraterrestrial life is rare or non-existent" hypothesis and clicked on the bolide link which links to Meteoroid however there doesn't appear to be a Bolide section on that page anymore. I think that section was renamed to Meteoroid. I would've corrected the link but I can't edit the article. 174.215.1.49 (talk) 01:56, 21 July 2018 (UTC)

Creationism as a possible explaination?
Don't give me crap about it not being scientific--it's just as believable as the simulation theory and the "we are purposely isolated" theory. — Preceding unsigned comment added by Hjk321 (talk • contribs) 02:27, 2 March 2018 (UTC)

Amen. — Preceding unsigned comment added by 208.101.149.206 (talk) 21:23, 25 September 2018 (UTC)

Voluntary extinction should be listed as an example under "It is the nature of intelligent life to destroy itself"
I am a novice editor. I boldly did a couple of edits but they were undone and I was advised to come here first. I propose adding the following text after "poorly designed artificial intelligence.":

", or voluntary means such as speciecide or abstaining from reproduction"

It appears this concept is missing from the page and is a very real possibility; Some human cultures have practiced this in the past and there are real movements such as the Voluntary Human Extinction Movement and Antinatalism/Efilism. I personally believe these to be very noble and enlightened risk-aversion strategies to counter suffering in the universe.

Can someone also please explain what happens next here? If there is consensus, who then gives a green light to an edit? Thanks Antinatalist (talk) 14:16, 11 October 2018 (UTC)
 * Hello. Adding that concept (or any concept for that matter) relies on quoting a reliable source or reference. See: WP:RS. If the reference is from a science-based reputable source, and non-fringe, then you add the info yourself. In this case, "voluntary extinction" seems poorly worded and may be difficult to support. In the human case, nuclear holocaust and global warming seem to be leading to our death, but is not really an intentional "voluntary" extinction, but greed and recklessness. Cheers, Rowan Forest (talk) 14:29, 11 October 2018 (UTC)


 * Hi Rowan Forest, how can I reference an unpopular, novel, or missing hypothetical explanation? And if I turn out to be its only proponent, we have to start somewhere! And are you suggesting "intentional extinction" instead? See: https://en.wikipedia.org/wiki/Voluntary_Human_Extinction_Movement (which is listed as one of only 150 social movements on Wikipedia https://en.wikipedia.org/wiki/List_of_social_movements!). Now climate caused extinction might be more likely, but it is no more valid in such a list of hypotheses. And what do you mean by 'support'? I believe that many thousands actively support voluntary human extinction, but I can't prove it. I do consider it to be an intelligence-motivated move, therefore I postulate that conscious alien beings probably tried it in the past, and may have succeeded, hence why we didn't get to meet them (and perhaps we should thank them for it!).Antinatalist (talk) 15:50, 11 October 2018 (UTC)
 * Hello. According to Wikipedia's quality standards for a science article -even if hypothertical- if the concept is "unpopular, novel" and not assessed/published by experts (e.g. a WP:Reliable source), then it is considered WP:Fringe, and therefore is not useful. If you are the main proponent of the concept and have not published peer-reviewed articles on "voluntary extinction" especially in the context of the Fermi paradox, it would be WP:OR (No original research), which is not good either. I think I will now let other involved editors comment on this, if they feel inclined to do so. Cheers, Rowan Forest (talk) 16:32, 11 October 2018 (UTC)


 * Aha I've just found my very hypothesis under Reference [74] (Nick Bostrom) just a couple of lines down! "4.7 Something unforeseen". Apologies for not spotting it earlier. I am much happier now, but I would still like to make my edit if possible, anyone? How does one get consensus/approval by the way? Thanks, Antinatalist (talk) 17:11, 11 October 2018 (UTC)

Criticism of logical basis section
I have found a draft version of the Robert A. Freitas, Jr. paper There Is No Fermi Paradox - Draft version. I think it is of very limited scientific value at best, laughable at worst. It all comes down to the proposition that an ET civilization could be observing us without our knowledge. All this dressed in fancy logical calculus. Mmom (talk) 23:39, 3 November 2018 (UTC)

I agree. I had to look up each kind of logic, then read the paper, so it's too jargon-filled as written. And I think (almost) everyone treats this a statement in model logic. Probably there are many sites life may arise, most likely we have no evidence (but there is some small chance UFO reports are true), etc. So I took the section out, but keep it here for reference, if someone can cast the argument into everyday words. LouScheffer (talk) 02:54, 5 November 2018 (UTC)
 * ---Criticism of logical basis

The Fermi paradox has been criticized as being based on an inappropriate use of propositional logic. According to a 1985 paper by Robert Freitas, when recast as a statement in modal logic, the paradox no longer exists, and carries no probative value.