The Corner

Science & Tech

The Coronavirus-on-a-Chessboard Problem

A used face mask on a street in New York City, March 14, 2020 (Eduardo Munoz/Reuters)

There’s an old story sometimes told about the inventor of chess and an Indian king. As a reward for coming up with the game, the inventor asked to be paid according to a simple formula. He’d get one grain of wheat for the first square on the chessboard, two for the second, four for the third, eight for the fourth, and so on, with the number doubling each square through all 64 squares. The king laughed this off as a meager reward.

Turns out that’s 18-odd quintillion grains of wheat.

You might not want to be the inventor of chess in this scenario. Per Wikipedia, “versions differ as to whether the inventor becomes a high-ranking advisor or is executed.” But you don’t want to be the king either, laughing off an unthinkably large sum.

Most estimates put the doubling time of COVID-19 infections at a week or less in the early stages of its spread. At this rate, infections can become 10,000 times as numerous as they are every few months. Take no solace in the fact that the infection and death statistics may be relatively low now; this represents but the first few squares of the chessboard.


The Latest