Earth now weighs six ronnagrammes: New metric prefixes voted in

Published November 18, 2022
<p>A Blue Marble image of Earth taken from the VIIRS instrument aboard Nasa’s Earth-observing satellite Suomi NPP, January 25, 2012. — Reuters/File</p>

A Blue Marble image of Earth taken from the VIIRS instrument aboard Nasa’s Earth-observing satellite Suomi NPP, January 25, 2012. — Reuters/File

Say hello to ronnagrammes and quettametres: International scientists gathered in France voted on Friday for new metric prefixes to express the world’s largest and smallest measurements, prompted by an ever-growing amount of data.

It marks 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.

Joining the ranks of well-known prefixes like kilo and milli are ronna and quetta for the largest numbers — and ronto and quecto for the smallest.

The change was voted on by scientists and government representatives from across the world attending the 27th General Conference on Weights and Measures, which governs the SI and meets roughly every four years at Versailles Palace, west of Paris.

The UK’s National Physical Laboratory, which led the push for the new prefixes, confirmed that the resolution had passed in a statement.

The prefixes make it easier to express large amounts — for example, always referring to a kilometre as 1,000 metres or a millimetre as one-thousandth of a metre would quickly become cumbersome.

Since the SI was established in 1960, scientific need has led to a growing number of prefixes. The last time was in 1991 when chemists wanting to express vast molecular quantities spurred the addition of zetta and yotta.

A yottametre is a one followed by 24 zeroes.

But even the mighty yotta is not enough to handle the world’s voracious appetite for data, according to Richard Brown, the head of metrology at the UK’s National Physical Laboratory.

“In terms of expressing data in yottabytes, which is the highest prefix currently, we’re very close to the limit,” Brown told AFP.

“At the bottom end, it makes sense to have a symmetrical expansion, which is useful for quantum science, particle physics — when you’re measuring really, really small things.”

New weight of the world

The new prefixes can simplify how we talk about some pretty big objects.

“If we think about mass, instead of distance, the Earth weighs approximately six ronnagrammes,” which is a six followed by 27 zeroes, Brown said.

“Jupiter, that’s about two quettagrammes,” he added — a two followed by 30 zeros.

Brown said he had the idea for the update when he saw media reports using unsanctioned prefixes for data storage such as brontobytes and hellabytes. Google in particular has been using hella for bytes since 2010.

“Those were terms that were unofficially in circulation, so it was clear that the SI had to do something,” he said.

However metric prefixes need to be shortened to just their first letter — and B and H were already taken, ruling out bronto and hella.

“The only letters that were not 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 are very, very loosely based on the Greek and Latin for nine and 10,” Brown said.

The new prefixes should “future-proof the system” and satisfy the world’s need for higher numbers — at least for the next 20 to 25 years, he added.

Opinion

Editorial

A grave tragedy
Updated 08 Feb, 2023

A grave tragedy

It is hoped that Pakistan continues to send as many personnel and relief goods as needed to Turkiye, Syria.
Pharma shutdown
08 Feb, 2023

Pharma shutdown

IN the midst of an economic and political maelstrom, a fresh crisis threatens the availability of drugs in the...
PSL season
08 Feb, 2023

PSL season

THE exhibition match between Quetta Gladiators and Peshawar Zalmi at Quetta’s Bugti Stadium has set the tone for...
No pardon for rape
Updated 07 Feb, 2023

No pardon for rape

Cultural filters and biases can often lead to faulty applications of the law.
Health insurance
07 Feb, 2023

Health insurance

THE planning ministry is reported to have raised objections to Punjab’s flagship universal health coverage...
The people’s demands
07 Feb, 2023

The people’s demands

AS the people of KP are literally on the frontline of the battle against terrorism and violent extremism, they are...