How much is a trillion dollars? Vast. Enough to buy all the homes in Queensland. Ten times as much as Jeff Bezos or Bill Gates owns. The market value of Apple. All the money earned in Australia in six months.

In this time of coronavirus we are facing a lot that is new. One of those things is the concept of trillions. The number of viruses in your body? Trillions. The amount of money the US government is spending on stimulus? Trillions.

The Japanese government has announced a stimulus package worth US$1 trillion, or 108 trillion yen, while here at home we are looking at racking up perhaps a trillion Australian dollars in national debt.

Understandably, our heads are spinning. Human brains are not adept at numbers beyond those we could count to in a lifetime.

As an illustration of how human imagination struggles with large sums, take the Forbes rich list of fictional characters. It includes no characters richer than the richest real-life people. Scrooge McDuck tops the list at US$44 billion but Mark Zuckerberg (US$62 billion) could buy and sell him.

Another example: when YouTube was launched it never imagined videos would be played more than a billion times. In 2012 Psy’s song “Gangnam style” hit that mark and briefly broke the system.

Trillions are not yet familiar. This is the way with large numbers. We are mostly discomfited by them and keep them at bay until forced to admit they are necessary.

For a long time, in the English language, “thousand” was enough. English had no single word for a larger number. For millenia, if the English needed to count higher they spoke of a thousand thousand. This lasted until the time of Chaucer, around 700 years ago. Then the word million was imported from the continent and the English language became suddenly more numerate.

The Romans were the same. Their number system topped out with M (1000), and could count no higher than MMMCMXCIX, or 3999. (Not all the classical world was so numerically inhibited. The Greeks were well advanced of the Romans — when challenged to count all the grains of sand in the world, Archimedes figured out numbers with which he could.)

But modern life involves relentless inflation of large numbers. This has not just one cause, but a myriad: population growth, economic growth, and inflation. Moore’s Law. The ability of science to discern and tabulate ever smaller constituent parts, as well as see ever broader horizons. Each of these force us to deal with larger and larger figures.

Still, we adopt the numbers only as needed. Take computers. We comfortably speak these days of megabytes and gigabytes, and terabytes are becoming de rigueur, yet petabytes and exabytes remain alien territory. We will get to them later.

Researching the history of the trillion, I wanted to know when the word became popular. So I turned to Google’s Ngram viewer. It is a wonderful resource that shows the frequency with which words appear in English language books over the past hundred or so years.

As the next graph shows, writing about millions was in serious ascendancy in the 20th century. But it peaked in the 1970s and has been in decline since. “Billion” peaked only 20 years after the peak in the word million. And trillion is rising.

The next graph zooms in on the word trillion. Around 1965 it hit an inflection point. Over the second half of the last century it became ten times more common. Note that this dataset contains data only until 2000 — talk of trillions must by now be higher still. Also: we ought to prepare for the quadrillion to cease to sound like make-believe and become a functional part of our vocabulary.

As economies grow, and populations grow, and inflation works its magic, numbers in the economy get bigger and bigger. The first billion-dollar listed company in the USA was US steel in 1901. General Electric was the first $100 billion company in 1995. Apple became the first trillion-dollar company in 2018.

Personal fortunes rise alongside the value of these large companies. Bill Gates has assets valued at around US$100 billion. By 2042, however, he is expected to become the first USD trillionaire. (Or at least he was forecast to be until coronavirus came along…)

Of course, some countries had trillionaires long ago. In 1946, Hungary had thousands of them. Amid an outbreak of hyperinflation Hungary printed a sextillion pengo note. (A sextillion is one followed by 21 zeroes.) One reason they let the inflation get so high? They were eager to pay back very high levels of government debt, and knew high inflation would shrink the debt very quickly.

The problem was this: growth in prices proceeded exponentially. Exponential growth, as anyone following viral transmission rates can tell you, is a powerful thing. You end up at much bigger numbers than you thought, much sooner than expected.

In the post-virus world, there might be clamour to reduce debt loads by unleashing inflation. If that happens all around the world, we might be dealing with quadrilions sooner rather than later.