We’ve all experienced the freaky effects of déjà vu. Maybe you’re going for a walk and feel the need to stop because you’ve felt this exact moment before. Or perhaps you’re meeting someone for the ...

A few days ago, I was visiting a new coffee shop in an unfamiliar neighborhood. In line to place my order, a polite stranger in front turned around, nodded at me, and said, "Hello." In that otherwise ...

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 curiouskidsus@theconversation.com. Starting in the late 1800s, many theories began ...