There’s a name for a new big, extreme number: quetta (a 1 with 30 zeros)

The amount of data is growing so fast. The world threatened to have no official term for that swelling wave. Until now. At the International Conference on Weights and Measures in Paris last week, governments agreed to include four new terms in the international system of units with immediate effect. This SI system contains the standard units for measuring, for example, mass (such as a kilogram) and speed.

The four new terms are: ronna, quetta, ronto and quecto. The first two represent the respective units 10²⁷ and 10³⁰ – successive terms in the SI system always jump by a factor of a thousand. For the record: 10³⁰ is a 1 with 30 zeros behind it. Until now, the system only went up to 10²⁴a quantity for which the term ‘yotta’ was accepted in 1991.

Humans are expected to produce 10 within a few years²⁴ yottabyte of data per year. “After that, that amount will grow rapidly,” says Richard Brown, who coined the terms and works at the National Physical Laboratory near London.

The use of the terms is not limited to data streams, he says. To give another example, the Earth weighs about one ronagram.

Because the SI system is symmetrical, Brown explains, in addition to new terms for the very large, two new terms for the very small have also been immediately accepted. Ronto stands for 10^-27 en quecto for 10^-30. The mass of an electron is about a quectogram.

According to Gert Rietveld, senior scientist at the VSL National Metrology Institute, the inclusion of the new terms in the SI system is “a very good idea.” Google already uses the term “hella” for a quantity of 10²⁷ to bytes. Elsewhere the term ‘bronto’ has been coined for it. “There is a threat of a proliferation of terms,” says Rietveld. “While you prefer to use one official, internationally accepted standard for a good exchange and trade of data.”

Brown says he is horrified by those alternative terms. If only because they do not comply with the guidelines. For example, a new term for the SI system should start with a letter that has not been used before. “And only the r and the q were still available,” says Brown.

But what if the data stream grows so fast that it will soon go beyond the terms ronna and quetta? Which letters should be used? Brown sees that it will not happen in the next 25 years. Then, if terms are needed for even larger or smaller quantities, “we may be able to move to using double terms,” he says. As has been done for a while before, say, the term pico (one trillionth, 10^-12) was accepted. “That was then called micro-micro.”