# Category Archives: featured

## Prime After Prime

Are the prime numbers sprinkled randomly along the number line, like windblown seeds?Of course not: Primality is not a matter of chance but a product of simple arithmetic. A number is prime if and only if no smaller positive integer … Continue reading

## Traffic Jams in Javascript

Building bigger roads can make traffic worse. The usual explanation for this counterintuitive and counterproductive outcome is that bigger roads attract bigger shopping malls, which in turn attract more cars. But that’s not the whole story. In the 1960s Dietrich … Continue reading

## Sunshine In = Earthshine Out

No computer simulations have ever had broader consequences for human life than the current generation of climate models. The models tell us that rising levels of atmospheric carbon dioxide and other greenhouse gases can trigger abrupt shifts in the planet’s … Continue reading

## Dancing with the Spheres

In my latest American Scientist column I’m packing spheres again. The goal this time is to maximize the number of contact points where spheres touch each other. For example, four spheres in a tetrahedral cluster have six contacts; this is … Continue reading

## 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