ronto-

See also: rōntõ, rontó, and Rontó

English

This English term is a hot word. Its inclusion on Wiktionary is provisional.
SI prefix
r Previous: quecto-
Next: yocto-

Etymology

Blend of r (an arbitrarily chosen initial letter) +‎ Ancient Greek ἐννέα (ennéa, “nine”) +‎ -to (to match the final syllable of the SI prefixes from femto- downwards).

Coined by Richard J. C. Brown and adopted by the General Conference on Weights and Measures in 2022 as an expansion to the metric prefixes beyond 10±24.

Some popular unofficial terms already in use were hella-, bronto- and xenna-, but terms beginning with the same letters as existing prefixes were considered undesirable, as were those beginning with common scientific letters such as b or x. Richard J. C. Brown suggested that the new terms begin with r and q, due to their rarity as unit symbols, and that the trends followed by the other prefixes be continued: that they be based on Latin or Greek; that large prefixes end with -a and small prefixes end with -o; that they should be in corresponding large and small pairs; and that the first letters of each prefix should be in reverse alphabetical order (as has been the case for the newer prefixes). He therefore suggested ronna- and ronto- (evoking Ancient Greek ἐννέα (ennéa) and Latin novem (“nine”)), and quecca- and quecto- (evoking Ancient Greek δέκα (déka) and Latin decem (“ten”)), because as 1027 and 1030 when written have nine and ten groups of zeroes, respectively. These were adopted, with quecca- changed to quetta-.[1][2]

Pronunciation

Prefix

ronto-

  1. In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10−27 (short scale octillionth or long scale quadrilliardth). Symbol: r
    Synonym: xenno-
    Antonym: ronna-
    • [2022 October 2, “Time and other units get tweaks”, in Science, volume 378, →DOI, page 933:
      For example, 1 ronnameter (Rm) is 1 billion billion billion meters and 1 quettameter (Qm), 1000 times bigger still; 1 rontometer (rm) is one-billionth of a billionth of a billionth of 1 meter and 1 quectometer (qm), one-thousandth of that.]
    • 2023 January 23, Elizabeth Gibney, “How many yottabytes in a quettabyte? Extreme numbers get new names”, in Nature, →DOI:
      Earth’s mass is on the order of a ronnagram, and an electron’s mass is about one rontogram.
    • 2024, J. Martin Strangeweather, The Eidetic Afterlife Hypothesis‎[4], Santa Ana Literary Association, →ISBN, page 107:
      Infinite degrees of separation (picoseconds, femtoseconds, attoseconds, zeptoseconds, yoctoseconds, rontoseconds, quectoseconds, etcetera) exist between any nanosecond and its immediate successor.
    • 2024, Anderson A. Tomaz, Rafael S. Mattos, Mario Barbatti, “Gravitationally-induced wave function collapse time for molecules”, in Physical Chemistry Chemical Physics, volume 26, page 20792:
      We applied these models for systems ranging from a small isolated molecule, for which the collapse time is of the order of a billion years, to mesoscopic crystals, whose collapse could occur within days, and macroscopic systems, collapsing within a rontosecond (10-27 s).
English terms prefixed with ronto-
rontogram
rontosecond

Translations

References

  1. ^ Richard Brown (24 June 2019), “Extending the available ranges of SI prefixes”, in Bureau International des Poids et Mesures‎[1]
  2. ^ “Resolutions of the General Conference on Weights and Measures (27th meeting)”, in Bureau International des Poids et Mesures‎[2], 18 November 2022
  3. ^ “Ronnametry i quettagramy [Ronnametres and Quettagrams]”, in Przystanek nauka‎[3] (in Polish), 20 November 2022, archived from the original on 11 May 2026

Further reading

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