You know kilo, centi, and milli, but how about ronto? Four new metric prefixes got the official stamp of approval last week at the 27th General Conference on Weights and Measures held at Versailles, the extravagant palace outside of Paris. The scientists who gathered there agreed on the need for new prefixes to account for the increasingly extreme numbers involved in scientific inquiry.
The new prefixes ronna and quetta refer to the largest numbers, while ronto and quecto apply to the smallest. Ronna is a 1 followed by 27 zeroes, and quetta is a 1 followed by 30 zeroes. Ronto is 10^-27, and quecto equates to 10^-30.
The conference meets every four years at Versailles; it’s in charge of the International System of Units, which is the running list of metric system units. You can see a list of all the metric prefixes, including the four new additions, here. The additions are the first expansion to the list since 1991.
“The change was largely driven by the growing requirements of data science and digital storage, which is already using prefixes at the top of the existing range (yottabytes and zettabytes, for expressing huge quantities of digital information),” said a release from the UK’s National Physics Laboratory, which was involved in the new prefix adoptions. “These can be used with any SI unit, for example in the future we can be expected to talk about ronnametres and quettagrams.”
Richard Brown, the head of the laboratory, told AFP that Earth weighs about 6 ronnagrams, and Jupiter is about 2 quettagrams. Naming conventions hold that prefixes indicating larger numbers end in ‘a’ (like ‘giga’), while prefixes for smaller numbers end in ‘o’ (like ‘nano’). Brown said the prefix additions came about in part because he saw media reports using unofficial units, like brontobyes and hellabytes, for data storage, showing that there was a need for units for more extreme numbers.
These new prefixes should tide us over for at least a few years. We can only imagine the innovations that would necessitate names beyond quetta and quecto.
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