Brian Hayes in American Scientist:
Last year the National Debt Clock in New York City ran out of digits. The billboard-size electronic counter, mounted on a wall near Times Square, overflowed when the public debt reached $10 trillion, or 1013 dollars. The crisis was resolved by squeezing another digit into the space occupied by the dollar sign. Now a new clock is on order, with room for growth; it won’t fill up until the debt reaches a quadrillion (1015) dollars.
The incident of the Debt Clock brings to mind a comment made by Richard Feynman in the 1980s—back when mere billions still had the power to impress:
There are 1011 stars in the galaxy. That used to be a huge number. But it’s only a hundred billion. It’s less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers.
The important point here is not that high finance is catching up with the sciences; it’s that the numbers we encounter everywhere in daily life are growing steadily larger. Computer technology is another area of rapid numeric inflation. Data storage capacity has gone from kilobytes to megabytes to gigabytes, and the latest disk drives hold a terabyte (1012 bytes). In the world of supercomputers, the current state of the art is called petascale computing (1015 operations per second), and there is talk of a coming transition to exascale (1018). After that, we can await the arrival of zettascale (1021) and yottascale (1024) machines—and then we run out of prefixes!