Hannah Fry takes a spectacular look at the science of size. Hannah starts by asking whether things could be bigger, including Earth and living things. Show more

We try out three potential ways to become invisible and discover some surprising side effects.

There is a way that Earth could have a second sun, so we try it out to see what happens.

Find out how to shout from one side of the world to the other.

We imagine a world where it's possible to move things with your mind like films, but find that the laws of physics mean that this superpower wouldn't quite work like you'd expect.

We take inspiration from the natural world as we imagine a new kind of superhero that can walk up walls.

We look at whether some animals can get gigantic and find out that if you are being chased by a giant snail or a humungous butterfly, then fear not, you must be dreaming.

What would the planet be like if all other humans disappeared, leaving you as the last person on earth?

We find out what would happen if you shrank the earth. You could jump higher and move faster, but you would end up with altitude sickness even at sea level.

After Fred and Pete stumble upon a strange clock, they go on an adventure to St Michael's Mount, a castle that is sometimes an island, sometimes not, and is home to an unusual duck!

Brain asks the question of whether you can kick a ball to France. Footballer Leah Williamson and physicist Steve Mould are on hand to help find the answer.

Hannah Fry takes a look at the science of size. Here, she asks if things could be smaller, including the Earth, living things and the Sun. Show more

Brain wants to know what it would be like if we lived underwater. Zoologist Megan McCubbin and inventor Jun Kamei wade in with Leila to help.

Presenter Hannah Fry reveals how much our planet can change in just a single day and how these daily changes are essential to our existence. Show more

Ken's brain is searching for an answer to the question of whether we can talk with dogs. Leila knows just where to look, while Ken has help from Storm Huntley with her dog Boo.

Brain's question is a hot one, what if the floor really was lava. Leila tests a homemade lava-proof suit, Ken gets tips from gymnast Joe Fraser and lava-facts from Professor Chris. Show more

Ken's brain wants to know if it's possible to catapult yourself to the moon. Space expert Vinita Marwaha Madill and inventor Tom Stanton have answers - but Leila may have to test it out.

Brain loves playing rock paper scissors, but hates losing - so he asks Ken to find out how you can always win. Show more

Ken’s had enough of Brain’s questions, but that leads to a new one: why does Ken get so annoyed? Can psychologist Leila and presenter Andy Day help find the answer?

Brain asks the question of what it would be like living without electricity. Paralympian Sarah Storey, environmentalist Helena Marschall and a powerless Leila offer help.