Brian Greene, professor of physics and mathematics at Columbia University and co-founder of the World Science Festival, explains what we know about time travel so far. Following is a transcript of ...

To be perfectly honest, the idea of time travel terrifies me because of the catastrophic circumstances I could cause by even the slightest alteration to the timeline. In fact, if I was ever given ...

The transition of Tokyo from a green island to sprawling metropolis can be better understand when taking in the sights and sounds on the ground on this 40-mile trek to the city’s center. Share ...