Outer space is filled with trillions of burning, bright stars. So why is it so dark?

That question is called Olber's Paradox. People have pondered it since the 1800s.

The answer? Outer space is both extremely vast and extremely old. 14 billion years to be exact.

Many stars are so old that their light hasn't even reached us yet. They're also so spread out that they don't fill the sky with light.

Swipe up for the full story of Olber's Paradox and the darkness of space