ronna-
English
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Etymology
[edit]Blend of r (an arbitrarily chosen initial letter) + Ancient Greek ἐννέα (ennéa, “nine”) + -a (to match the final letter of the SI prefixes from mega- upwards).
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 as 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
[edit]- (General American) IPA(key): /ˈɹɒn.ə/
Prefix
[edit]ronna-
- In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 1027 (a short scale octillion or long scale quadrilliard). Symbol: R
Synonyms
[edit]- (none are standard) xenna-, hella-, bronto- (brontobyte)
