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 ...

Researchers have discovered that it’s possible to speed up, slow down, or reverse the flow of time in a quantum system. This ...

The science: Is time travel possible? Up until recently, physicists believed that time travel to the past was impossible because it required unusual matter or extreme warping of spacetime.

A scientist has mathematically proven the physical feasibility of paradox-free time travel. But once you go back, you might not like what you find.

Physicist Michio Kaku says new CERN experiments suggest time travel could be possible. Also, Wisconsin Gov. Scott Walker talks with WSJ editorial board members about how his state is outcompeting ...