In the season 2 episode "Mirror, Mirror," Star Trek perfected the alternate universe trope long before Hollywood's multiverse ...

We have not been able to detect dark matter yet, even though there are many aspects of the universe that suggest the existence of invisible matter. In one new theory, it is possible that dark matter ...

Here’s what you’ll learn when you read this story: A backward, mirror universe could explain the existence of dark matter. If an anti-universe exists, it would run backward in time, before the Big ...

Cosmologists are increasingly entertaining a radical possibility: that the cosmos might fold back on itself so that, on the ...