How Small Is the Universe?

Horizon plunges down the biggest rabbit-hole in history in search of the smallest thing in the Universe. It is a journey where things don't just become smaller but also a whole lot weirder. Scientists hope to catch a glimpse of miniature black holes, multiple dimensions and even parallel Universes. As they start to explore this wonderland, where nothing is quite what it seems, they may have to rewrite the fundamental laws of time and space.

Other episodes for this season

The Truth About Looking Young
Episode 1 - The Truth About Looking Y...
Mission to Mars
Episode 2 - Mission to Mars
Eat, Fast and Live Longer
Episode 3 - Eat, Fast and Live Longer
How Big Is the Universe?
Episode 4 - How Big Is the Universe?
How Small Is the Universe?
Episode 5 - How Small Is the Universe?
Defeating the Superbugs
Episode 6 - Defeating the Superbugs
The Creative Brain: How Insight Works
Episode 7 - The Creative Brain: How I...
How to Avoid Mistakes in Surgery
Episode 8 - How to Avoid Mistakes in...
The Truth about Taste
Episode 9 - The Truth about Taste
The Age of Big Data
Episode 10 - The Age of Big Data
The Secret Life of the Cat
Episode 11 - The Secret Life of the Ca...
Little Cat Diaries
Episode 12 - Little Cat Diaries
Fracking: The New Energy Rush
Episode 13 - Fracking: The New Energy...
Swallowed by a Black Hole
Episode 14 - Swallowed by a Black Hole
What Makes us Human?
Episode 15 - What Makes us Human?
The Truth About Personality
Episode 16 - The Truth About Personali...