Add Yahoo as a preferred source to see more of our stories on Google. In space, there are four dimensions: length, width, height and time. scaliger/iStock/NASA via Getty Images Plus About a century ...

A new theory claims dark matter and dark energy don’t exist — they’re just side effects of the universe’s changing forces. By rethinking gravity and cosmic timelines, it could rewrite our ...

Depending on how you look at it, the universe might not have an "end," after all. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. This article ...