There is a hypothetical class of particles that always travel faster than light. Einstein himself played around with the idea, calling them “ meta-particles,” but today we call them tachyons, a word ...

When you think about the idea of time travel, you likely think about the fantastic possibility of going backward in time to an event in the past, rather than our constant, inevitable march forward in ...

But here’s where time travel comes in: If you can travel faster than the speed of light, you could hypothetically send messages at speeds exceeding time, which means you can send a message backward.

A new study from the Pew Research Center finds that 10 percent of Millennials think a time machine would be cool—compared to just 3 percent of people over 65. It brings to mind my own mother ...