How Long Would It Take Bacteria to Eat the Earth?

A trillion bacteria weigh one gram, 500 million bacteria fit in a grain of sand, and other answers from order-of-magnitude thinking.

An artist’s rendering of microbes. Photo by Elena Mozhvilo on Unsplash.

When I first heard that bacteria in the body outnumber human cells ten-to-one, eight years ago, I thought, “Now that is truly terrifying, to be mostly…