As the scale of science expands, so does the language of prefixes

N OWAYS EVERY factory seems to be a “gigafactory”. Elon Musk, the boss of Tesla, recently cut the ribbon on a fourth facility by that name, in Berlin. Tesla’s Shanghai Gigafactory has been in the news for a covid-related halt in production. The Taiwan Semiconductor Manufacturing Company ( TSMC ), one of the world’s most important chipmakers, has begun touting its “gigafabs”. Nissan has announced a gigafactory in Sunderland, in the north-east of England.

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Giga- is a prefix meaning “a billion” of something. The Oxford English Dictionary drily describes it as an “arbitrary derivative” of the Greek gigas, “giant”. (The ancient Greeks apparently had no need for a specific word for “billions”.) But the various gigafactories don’t always produce billions of anything: each month the TSMC gigafab can start about 100,000 silicon wafers used for making microchips, making it more of a hectokilofactory. (Hekaton and khilioi really are Greek for 100 and 1,000.) Tesla, at least, can claim that its original Gigafactory in Nevada supplies billions of watt-hours of battery-cell output per year.

As science has expanded to the huge and the tiny, the need for new metric-system prefixes has grown accordingly. These have made their way into common parlance mostly through computing. In the 1980s a good computer might have had 256 kilobytes of memory. The first hard drives with a million bytes’ worth of storage introduced the world to the megabyte, a jaw-dropping notion at the time. (Megas, too, was generic in Greek, meaning “great”. A megalomaniac has delusions of greatness, not millionaire status.) But at least many people had heard of the mega- prefix before. When the billion-byte mark was crossed, many began encountering “giga-” for the first time, strange new linguistic territory opened up by Moore’s Law.

It can be only a matter of time before giga- feels ho-hum; after all, a memory card with 128 gigabytes of storage is today the size of a thumbnail and costs around $20. Affordable hard drives now have terabyte—that is, trillion-byte—storage. Having run out of terms for “big”, the borrowers from Greek got creative: teras means “monster”. As billions become workaday, tera- will become the new giga-.

For a while, anyway. Whether or not computing power continues to grow at the rate it has in the past—a matter of some debate—it is inevitable that peta- and exa- will make their debut in the popular consciousness. Already selected by the International Committee for Weights and Measures ( ICWM ), peta- and exa- come from Greek penta (five) and hexa (six), representing 1,0005 and 1,0006. After that, the ICWM ’s prefix-mongers have decided to go for Latin rather than Greek. They considered septa- and octo- for 1,0007 and 1,0008. But the proposed s- shortening of septa- could have been confused with an abbreviation for a second, and the o- for a zero. So septa- and octo- were deformed to zetta- (1,0007) and yotta- (1,0008).

As the system of prefixes can now encompass a 1 followed by 24 zeroes, most scientists will be happy to use 1025 and the like for anything bigger. But not college students: a group at the University of California, Davis, started a petition proposing a new prefix, hella-, for 1027. Northern Californians will know hella as an adverb, derived from hell of, as in “he’s hella ugly.” And as a prefix, it has gained a bit of currency in the technology press, if only jokingly. It would be the first of the prefixes for huge numbers not to come from the classical languages. “Hell” is a Germanic word.

Small is cool too. The fractional equivalent of giga- is nano-, the prefix denoting a billionth. Nanotechnology is big, so to speak: nanoparticles making up nanobeads are hot topics in science and technology. The hip feel conveyed by the prefix was borrowed by Apple, which named its tiny music player the Nano. (Again, the etymology is classical: nanos is the Greek word for “dwarf”.) If nano-, too, eventually becomes humdrum, look out for pico- (a trillionth, from Spanish pico for “a little bit”), femto- and atto-, from the Danish for 15 and 18, referring to 10-15 and 10-18.

Classicists once scoffed at words, such as “television” and “monolingual”, which mix up Greek and Latin roots. Now they are obliged to behold gigafactories and decacorns (private companies that are worth over $10bn), nanoseconds and terawatts, to say nothing of hellabytes. These may seem ungainly, but the Hellenophiles can console themselves that the chimera—an unlikely combination of lion, goat and snake—was, after all, a Greek beast.

Read more from Johnson, our columnist on language:

A guide to renamed cities (Mar 26th)

Rules for teaching grammar in schools (Mar 12th)

A language without a flag and a state is still a language (Feb 12th)