rontoとは 意味・読み方・使い方

語源

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.

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 10 and 10 when written have nine and ten groups of zeroes, respectively. These were adopted, with quecca- changed to quetta-.

発音

• (General American) IPA: /ˈɹɑn.toʊ/

接頭辞

ronto-

1. In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10 (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, 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 s).

関連する語

参照

Further reading

• ronto- on Wikipedia.Wikipedia