Say hello to roronnagrams and quettameters: International scientists gathered in France on Friday for new metric prefixes to express the world’s largest and smallest measurements, prompted by an ever-expanding amount of data.
It is the first time in more than three decades that new prefixes have been added to the International System of Units (SI), the agreed global standard for the metric system.
Besides the well-known prefixes such as kilo and milli, ronna and quetta are for the largest numbers – and ronto and quecto for the smallest.
The amendment was voted on by scientists and government representatives from around the world who attended the conference 27th General Conference on Weights and Measureswhich governs the SI and meets approximately every four years at the Palace of Versailles, west of Paris.
That of the UK National Physics Laboratorywho led the push for the new prefixes confirmed that the resolution had been passed in a statement.
The prefixes make it easier to express large amounts – for example, always referring to a kilometer as 1000 meters or a millimeter as one-thousandth of a meter would quickly become cumbersome.
Since the establishment of the SI in 1960, scientific need has led to a growing number of prefixes. The last time was in 1991, when chemists who wanted to express huge molecular quantities pushed for the addition of zetta and yotta.
A yotta meter is a one followed by 24 zeros.
But even the mighty yotta isn’t enough to handle the world’s voracious hunger for data, according to Richard Brownthe head of metrology at the British National Physical Laboratory.
“In terms of expressing data in yottabytes, which is currently the highest prefix, we are very close to the limit,” Brown told AFP.
“On the downside, it makes sense to have a symmetric expansion, which is useful for quantum science, particle physics — when you’re measuring very, very small things.”
New weight of the world
The new prefixes can simplify the way we talk about pretty big objects.
“If we think about mass, rather than distance, the Earth weighs about six ronnagrams,” which is a six followed by 27 zeros, Brown said.
” Jupiterthat’s about two quettagrams,” he added — a two followed by 30 zeroes.
Brown said he came up with the idea for the update when he saw media reports using unapproved data storage prefixes, such as brontobytes and hellabytes. Google, in particular, has been using hella for bytes since 2010.
“Those were terms that were circulating unofficially, so it was clear that the SI had to do something,” he said.
However, metric prefixes must be shortened to just their first letter – and B and H were already in use, excluding bronto and hella.
“The only letters that weren’t used for other units or other symbols were R and Q,” Brown said.
Convention dictates that the larger prefixes end in an A and the smaller ones in an O.
And “the middle of the words is very, very loosely based on the Greek and Latin for 9 and 10,” Brown said.
The new prefixes should “future-proof the system” and meet the world’s need for higher grades — at least for the next 20 to 25 years, he added.
© Agence France-Presse