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

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 ...

Hints of a mirror cosmos have a way of gripping the imagination, and recent chatter about “first proof” of a parallel universe has pushed that fascination back into the spotlight. Behind the viral ...

The surface of Earth is finite. We can measure it. If it was expanding, then its size would grow with time. And once again, good ol' Earth helps us understand what the universe might be doing beyond ...