Graphs are everywhere. In discrete mathematics, they are structures that show the connections between points, much like a ...

That question in the headline was the challenge posed by a group of open knowledge junkies in Germany who wanted to understand how a person’s Schufa was calculated. Schufa is a credit bureau that ...

The original version of this story appeared in Quanta Magazine. Imagine a town with two widget merchants. Customers prefer cheaper widgets, so the merchants must compete to set the lowest price.