# Category Archives: featured

## The abc game

Five years ago I wrote about a rumored proof of the abc conjecture, an idea from the 1980s that stands at the juncture between the additive and the multiplicative parts of number theory. Now there’s more abc news, and this … Continue reading

## Statistical mechanics of magnet balls

They come out of the can in a gleaming 6 × 6 × 6 cubic crystal. It took me a day to figure out how to get them back into the can. But that’s not the deepest mystery about these … Continue reading

## World3, the public beta

Forty years ago I had my first close encounter with mathematical models of doomsday. The Limits to Growth, published in the spring of 1972, offered a grim vision of environmental and economic collapse, based on the implacable logic of a … Continue reading

## The n-ball game

The area enclosed by a circle is πr2. The volume inside a sphere is 4∕3πr3. These are formulas I learned too early in life. Having committed them to memory as a schoolboy, I ceased to ask questions about their origin … Continue reading

## A slight discrepancy

The image above shows the mesh top of a patio table, photographed after a soaking rain. Some of the openings in the mesh retain drops of water. What can we say about the distribution of those drops? Are they sprinkled … Continue reading