Like stretch marks left on skin that expanded too quickly or cracks embedded in freezing ice, cosmic strings are artifacts of what the universe looked like in the moments before it rapidly changed ...

Vanderbilt University physicist Lorenzo Gavassino isn't so sure this is as big an obstacle as time-traveler pessimists have ...

Using scanned maps and data from the United States Geological Survey (USGS), Esri developed an interactive tool to explore ...

Time travel is possible. For example, an object traveling at high speeds ages more slowly than a stationary object. This means that if you were to travel into outer space and return, moving close ...

Black holes, vast regions of space with gravity so strong that even ... offers a potential pathway to unlocking the mysteries of time travel." ...

"The lightsail will travel faster than any previous spacecraft, with potential to eventually open interstellar distances to ...

One of the most famous paradoxes ever, the grandfather paradox, cautions against making changes that could break the timeline if you were to ever travel back in time. But, according to one scientist, ...

Today, space travel for the average person is no longer a matter of "if" but "when," thanks to the imaginations of self-funded business magnates with an eye on the sky. Space is the tourism ...

(Mark Kelly, now a U.S. senator, also spent a brief time in space ... not all — underscoring the potential health hazards of space travel, many of which are unknown. These will ratchet up ...