The Fermi Conversation effect

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Since unidentified aerial phenomena (=UFOs) have been in the news recently, so has the "Fermi Paradox". And the Wikipedia article on the Fermi Paradox has an interesting linguistic resonance, aside from all the speculation about what communication with aliens might be like. Here's Wikipedia on the original Los Alamos conversation:

In the summer of 1950 at Los Alamos National Laboratory in New Mexico, 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).

Those different memories might reflect different conversations. But they might just as well illustrate the fact that our memory of exact word sequences usually fades more quickly than our memory of (contextually interpreted) meanings.

More broadly, the exact auditory sensations normally fade very quickly; the corresponding word sequences fade a bit more slowly; and the interpreted meanings last longest.

These generalizations can be overcome to some extent if the sound or the text has especially memorable characteristics. (And the question of what "memorable" means in this context is interesting.)

This primacy of interpretation over (the various stages of) sensation and perception also helps to explain why it's so hard to transcribe disfluencies accurately — you may notice that a given phrase has a filled pause or a repeated word, but be unable to recall exactly where it happened without listening to the phrase again.



  1. bks said,

    July 6, 2021 @ 7:32 am

    Quite. Fortunately my wife is available to correct my mistaken recollection of what I said.

  2. Jerry Friedman said,

    July 6, 2021 @ 10:49 am

    My normal experience is indeed remembering meanings rather than exact words, but if I reread a book (I've been bingeing on Nero Wolfe recently), I often don't recognize anything till I see a phrase that happened to stick in my mind.

  3. JPL said,

    July 6, 2021 @ 6:18 pm

    This phenomenon is probably related to a probably common type of experience I've often had: remembering what was said in a conversation and not being able to remember which language it was said in.

  4. Julian said,

    July 6, 2021 @ 6:42 pm

    On the interesting question of what 'memorable' means: example: when the words themselves (as opposed to the meaning) are emotionally salient.
    When travelling overseas in a place where I know a bit of the language, I'm pretty forward in trying to practice it on people ('Excuse me – can you tell me where the post office is?' etc). Some of the resulting three-turn, 10 second conversations I can remember verbatim years later.
    The salience comes from the extra cognitive demands of maintaining the conversation in the foreign language.

  5. Philip Taylor said,

    July 7, 2021 @ 5:37 am

    I agree with Julian that one does tend to remember the exact words used when one is speaking a foreign language in which one is not 100% confident, but I do wonder whether our memories in this respect are as accurate as we fondly believe. Did I really say Nǐde Hànyǔ hěn hǎo ! to a Chinese waiter in Wǔ Hàn, or did I perhaps use Zhōngwén rather than Hànyǔ ? And can I really be sure, 16 years on ?

  6. Stephen Goranson said,

    July 7, 2021 @ 6:55 am

    This reminds me of the differing accounts of what War Secretary Edwin Stanton said right after Abraham Lincoln died. “Now he belongs to the ages” or “Now he belongs to the angels.” Most attestations have “ages.” But these attestations start with Hay, about 25 years later. At that time, historical perspective may have seemed apt. But weary, and religious, Stanton, in the moment, may have had in mind the story of the beggar Lazarus as told in Gospel of Luke 16:22: “The time came when the beggar died and the angels carried him to Abraham’s side.” Abraham to Abraham.

  7. KeithB said,

    July 9, 2021 @ 8:43 am

    To go along with Julian, several of those in that group did not speak english as a first language (Teller and Fermi)

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