In 1865, William Stanley Jevons first described a paradox. He maintained that more efficient steam engines would not decrease the use of coal in British factories but would actually increase it. As ...

We are always solving problems, some of which have instantly obvious solutions and others that do not. In the latter case, the word puzzle comes to mind instead. A problem can be defined therefore as ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...