Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]. Why are there seven days in a week? – Henry E., ...

Waiting for the weekend can often seem unbearable, a whole seven days between Saturdays. Having seven days in a week has been the case for a very long time, and so people don’t often stop to ask why.

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, ...

You're currently following this author! Want to unfollow? Unsubscribe via the link in your email. Nico Laqua said he'd rather shave years off his life than see his startup fail. He cofounded Corgi, an ...