Ronnas and quettas: Scientists expand our measurements for size

Ronnas and quettas: Scientists expand our measurements for size

What is bigger: A ronna or a quetta?

Scientists meeting outside of Paris on Friday have the answer.

Rapid scientific advances and vast worldwide data storage on the web, in smartphones and in the cloud mean that the very terms used to measure things in weight and size need extending. And one British scientist led the push Friday to incorporate bold new, tongue-twisting prefixes on the gigantic and even the minuscule scale.

"Most people are familiar with prefixes like milli- as in milligram. But these are prefixes for the biggest and smallest levels ever measured," Dr. Richard Brown, head of metrology at the U.K.'s National Physical Laboratory who proposed the four new prefixes, told The Associated Press. Metrology is the study of measurement.

"In the last 30 years, the datasphere has increased exponentially, and data scientists have realized they will no longer have words to describe the levels of storage. These terms are upcoming, the future," he explained.

There's the gargantuan "ronna" (with 27 zeros after the one) and its big brother the "quetta" — (with 30 zeros).

Their ant-sized counterparts are the "ronto" (27 zeros after the decimal point), and the "quecto" (with 30 zeros after the decimal point) — representing the smaller numbers needed for quantum science and particle physics.

Supreme authority 

Brown presented the new prefixes to officials from 64 nations attending the General Conference on Weights and Measures in Versailles, outside of Paris — who approved them on Friday.

The entrance of the International Bureau of Weights and Measures is pictured in Sevres, outside Paris, in this photo taken Nov. 17, 2022. (Michel Euler/The Associated Press)

The conference, which takes place every four years in France, is the supreme authority of the International Bureau of Weights and Measures. The new terms take effect immediately, marking the first time since 1991 that any new additions have been made.

Brown said the new terms also make it easier to describe things scientists already know about — reeling off a list of the smallest and biggest things discovered by humankind.

Did you know that the mass of an electron is one rontogram? And that a byte of data on a mobile increases the phone's mass by one quectogram?

Further from home, the planet Jupiter is two just quettagrams in mass. While, incredibly, "the diameter of the entire observable universe is just one ronnameter," Brown said.

Not chosen randomly

He explained how the new names were not chosen at random: The first letter of the new prefixes had to be one not used in other prefixes and units.

"There were only the letters 'r' and 'q' that weren't already taken. Following that, there's a precedent that they sound similar to Greek letters and that big number prefixes end with an 'a' and smaller numbers with an 'o,"' he added.

"It was high time. (We) need new words as things expand," Brown said. "In just a few decades, the world has become a very different place."