Editing Fermi paradox (section)

==History==
Fermi was not the first to ask the question. An earlier implicit mention was by [[Konstantin Tsiolkovsky]] in an unpublished manuscript from 1933.<ref>Tsiolkovsky, K. (1933). ''The Planets are Occupied by Living Beings'', Archives of the Tsiolkovsky State Museum of the History of Cosmonautics, Kaluga, Russia. See [[:s:ru:Планеты заселены живыми существами (Циолковский)|original text]] in Russian [[Wikisource]].</ref> He noted "people deny the presence of intelligent beings on the planets of the universe" because "(i) if such beings exist they would have visited Earth, and (ii) if such civilizations existed then they would have given us some sign of their existence". This was not a paradox for others, who took this to imply the absence of extraterrestrial life. But it was one for him, since he believed in extraterrestrial life and the possibility of space travel. Therefore, he proposed what is now known as the [[zoo hypothesis]] and speculated that mankind is not yet ready for higher beings to contact us.<ref>{{cite journal |title=Tsiolkovsky – Russian Cosmism and Extraterrestrial Intelligence |author=Lytkin, V. |author2=Finney, B. |author3=Alepko, L. |journal=Quarterly Journal of the Royal Astronomical Society |volume=36 |issue=4 |date=December 1995 |pages=369 |bibcode=1995QJRAS..36..369L }}</ref> In turn, Tsiolkovsky himself was not the first to discover the paradox, as shown by his reference to other people's reasons for not accepting the premise that extraterrestrial civilizations exist.

In 1975, [[Michael H. Hart]] published a detailed examination of the paradox, one of the first to do so.<ref name="Hart" /><ref name=webb>{{cite book |last1=Webb |first1=Stephen |title=If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?: Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life |date=2015 |publisher=Springer International Publishing |isbn=978-3-319-13235-8 |edition=2 |url=https://www.springer.com/gp/book/9783319132358 |language=en |access-date=June 12, 2020 |archive-url=https://web.archive.org/web/20200612035828/https://www.springer.com/gp/book/9783319132358 |archive-date=June 12, 2020 |url-status=live }}</ref>{{rp|27–28}}<ref name=forgan>{{cite book |last1=Forgan |first1=Duncan H. |title=Solving Fermi's Paradox |date=2019 |publisher=Cambridge University Press |isbn=978-1-316-73231-1 |url=https://books.google.com/books?id=5U-PDwAAQBAJ |language=en |access-date=June 12, 2020 |archive-url=https://web.archive.org/web/20200625083852/https://books.google.com/books?id=5U-PDwAAQBAJ |archive-date=June 25, 2020 |url-status=live }}</ref>{{rp|6}} He argued that if intelligent extraterrestrials exist, and are capable of space travel, then the galaxy could have been colonized in a time much less than that of the age of the Earth. However, there is no observable evidence they have been here, which Hart called "Fact A".<ref name=forgan/>{{rp|6}}

Other names closely related to Fermi's question ("Where are they?") include the Great Silence,<ref name="Brin">{{cite journal
| url = https://ui.adsabs.harvard.edu/abs/1983QJRAS..24..283B/abstract
| title = The Great Silence - The Controversy Concerning Extraterrestrial Intelligent Life
| journal = Quarterly Journal of the Royal Astronomical Society
| author= Brin, Glen David 
| author-link = David Brin
| volume = 24
| issue = 3
| pages = 283–309
| date = August 1983
| bibcode = 1983QJRAS..24..283B
}}</ref><ref name=Annis>{{cite journal
|arxiv=astro-ph/9901322
|author=Annis, James
|title=An Astrophysical Explanation for the Great Silence
|journal=Journal of the British Interplanetary Society
|volume=52
|issue=1
|pages=19
|date=1999
|bibcode=1999JBIS...52...19A
}}</ref><ref name=Hope>{{cite magazine
| last = Bostrom
| first = Nick
| author-link = Nick Bostrom
| title = In Great Silence there is Great Hope
| magazine = MIT Technology Review
| date = May 2008
| pages = 72–77
| url = http://www.nickbostrom.com/papers/fermi.pdf
| access-date = September 6, 2010
| archive-url = https://web.archive.org/web/20110228111236/http://www.nickbostrom.com/papers/fermi.pdf
| archive-date = February 28, 2011
| url-status = live
}}</ref><ref name="Cirkovic2009" /> and {{lang|la|silentium universi}}<ref name=Cirkovic2009>{{cite journal
|author1=Milan M. Ćirković
|title=Fermi's Paradox – The Last Challenge for Copernicanism?
|date=2009
|doi=10.2298/SAJ0978001C
|journal=Serbian Astronomical Journal
|issue=178
|pages=1–20
|volume=178
|arxiv=0907.3432
|bibcode = 2009SerAJ.178....1C |s2cid=14038002
}}</ref> (Latin for "silence of the universe"), though these only refer to one portion of the Fermi paradox, that humans see no evidence of other civilizations.

=== Original conversations ===
[[File:Los Alamos aerial view.jpeg|thumb|[[Los Alamos National Laboratory]], Los Alamos, New Mexico, United States]]
In the summer of 1950 at [[Los Alamos National Laboratory]] in [[New Mexico]], Enrico Fermi and co-workers Emil Konopinski, Edward Teller, and Herbert York had one or several lunchtime conversations.<ref name="Eric-Jones">[http://www.fas.org/sgp/othergov/doe/lanl/la-10311-ms.pdf "Where is everybody?": An account of Fermi's question"] {{Webarchive|url=https://web.archive.org/web/20070629174738/http://www.fas.org/sgp/othergov/doe/lanl/la-10311-ms.pdf |date=June 29, 2007 }}, Dr. Eric M. Jones, Los Alamos technical report, March 1985. Jones wrote to Edward Teller on July 13, 1984, Herbert York on Sept. 4, and Emil Konopinski on Sept. 24, 1984.</ref><ref>{{cite web|last=Shostak|first=Seth|date=October 25, 2001|archive-url=https://web.archive.org/web/20060415185347/http://space.com/searchforlife/shostak_paradox_011024.html |url=http://www.space.com/searchforlife/shostak_paradox_011024.html|archive-date=April 15, 2006|title=Our Galaxy Should Be Teeming With Civilizations, But Where Are They?|work=Space.com|access-date=October 14, 2014 |url-status=dead}}</ref> In one, Fermi suddenly blurted out, "Where is everybody?" (Teller's letter), or "Don't you ever wonder where everybody is?" (York's letter), or "But where is everybody?" (Konopinski's letter).<ref name="Eric-Jones" /> Teller wrote, "The result of his question was general laughter because of the strange fact that, in spite of Fermi's question coming out of the blue, everybody around the table seemed to understand at once that he was talking about extraterrestrial life."<ref name="Eric-Jones" />

In 1984, York wrote that 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 such calculations that we ought to have been visited long ago and many times over."<ref name="Eric-Jones" /> Teller remembers that not much came of 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."<ref name="Eric-Jones" />

Fermi died of cancer in 1954. However, in letters to the three surviving men decades later in 1984, Dr. Eric Jones of Los Alamos was able to partially put the original conversation back together. He informed each of the men that he wished to include a reasonably accurate version or composite in the written proceedings he was putting together for a previously held conference entitled "Interstellar Migration and the Human Experience".<ref name="Eric-Jones" /><ref name="Interstellar Migration and the Human Experience, edited by Finney and Jones, 1985">[https://books.google.com/books?id=iKnaLbRtQasC&pg=PA249 ''Interstellar Migration and the Human Experience''], edited by Ben R. Finney, Eric M. Jones, University of California Press, 1985.</ref> Jones first sent a letter to Edward Teller which included a secondhand account from [[Hans Mark]]. Teller responded, and then Jones sent Teller's letter to Herbert York. York responded, and finally, Jones sent both Teller's and York's letters to Emil Konopinski who also responded. Furthermore, Konopinski was able to later identify a cartoon which Jones found as the one involved in the conversation and thereby help to settle the time period as being the summer of 1950.<ref name="Eric-Jones" />