A Brief History of Scientists Hunting for Time Travelers

Time travel is possible—or at least a lot of serious physicists say so. It's probably not possible to pull it off in a souped-up Delorean, but there are wormholes, Tipler cylinders, and other Einstein-inspired theories for how it could work. Which raises the question: Why haven't we met any visitors from another time? » 10/09/14 3:39pm 10/09/14 3:39pm

In Cosmos, The Only Thing More Important Than Evidence Is Imagination

The universe, they say, isn't just stranger than we imagine. It's stranger than we can imagine. After three episodes focused on matters solar and mundane, from the evolution of life to the orbital dynamics of comets in our little flat circle of spacetime, episode four tackles the limits of cosmic reality far beyond… » 3/31/14 9:20am 3/31/14 9:20am

Why does relativity mean that mass changes with speed?

Everyone knows that relativity plays hell with time, and that it can do a number on space, but what about mass? Why do objects get more or less mass depending on their relative speed? We're going to give you a quick explanation of why running can make you gain weight. No, we don't think it's fair either. » 1/09/13 11:19am 1/09/13 11:19am