page_title: Fermi paradox
section_title: Original conversation(s)
hierarchical_section_title: Fermi paradox / History / Original conversation(s)
caption_attribution_description: Aerial view of Los Alamos National Laboratory, "1995 aerial TA-3 south to north".
context_page_description: The Fermi paradox, named after Italian-American physicist Enrico Fermi, is the apparent contradiction between the lack of evidence for extraterrestrial civilizations and various high estimates for their probability.
  The following are some of the facts that together serve to highlight the apparent contradiction:
  There are billions of stars in the Milky Way similar to the Sun.
  With high probability, some of these stars have Earth-like planets.
  Many of these stars, and hence their planets, are much older than the Sun. If the Earth is typical, some may have developed intelligent life long ago.
  Some of these civilizations may have developed interstellar travel, a step humans are investigating now.
  Even at the slow pace of currently envisioned interstellar travel, the Milky Way galaxy could be completely traversed in a few million years.
  And since many of the stars similar to the Sun are billions of years older, the Earth should have already been visited by extraterrestrial civilizations, or at least their probes.
  However, there is no convincing evidence that this has happened.
context_section_description: At Los Alamos National Laboratory in the summer of 1950, Fermi and co-workers Emil Konopinski, Edward Teller, and Herbert York had one or several casual lunchtime conversation(s).
  Herb York does not remember a previous conversation, although he says it makes sense given how all three later reacted to Fermi's outburst.  Teller remembers seven or eight of them at the table, so he may well be remembering a different previous conversation.
  In one version, the three men discussed a spate of recent UFO reports while walking to lunch. Konopinski remembered mentioning a magazine cartoon which showed aliens stealing New York City trash cans, and as he wrote years later, "More amusing was Fermi's comment, that it was a very reasonable theory since it accounted for two separate phenomena."
  Teller remembered Fermi asking him, "Edward, what do you think. How probable is it that within the next ten years we shall have clear evidence of a material object moving faster than light?" Teller said, "10^-6" (one in a million). Fermi said, "This is much too low. The probability is more like ten percent" (which Teller wrote in 1984 was "the well known figure for a Fermi miracle").
  At lunch, Fermi suddenly exclaimed, "Where are they?" (Teller's remembrance), or "Don't you ever wonder where everybody is?" (York's remembrance), or "But where is everybody?" (Konopinski's remembrance).
  Teller wrote, "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." York wrote, "Somehow . . . we all knew he meant extra-terrestrials." However, Emil Konopinski was not emphatic that he immediately knew Fermi was referring to possible aliens, merely writing "It was his way of putting it that drew laughs from us."
  Regarding the continuation of the conversation, York wrote in 1984 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."
  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."
  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."
  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.
caption: Los Alamos National Laboratory
  Los Alamos, New Mexico, United States
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