Those of us who grew up coloring remember the cardinal rule: stay inside the lines. But those who pick up the Patterns of the Universe coloring book have to stay in the sines (and cosines and tangents ...

In waiting rooms, therapists’ offices, community centers, and kitchen tables across America, a once child-centered activity ...

A detail of the Mandelbrot set, a fractal named after Benoit Mandelbrot, the French mathematician who investigated it in the 1970s. If you were to zoom in at any point on the intricate, wiggly line, ...

I have never changed my mind about anything as quickly or completely as I changed my mind about adult coloring books. I found the trend mostly baffling and maybe a little dumb. But I saw some in a ...