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.

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.

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.

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.

Sometimes you want to go surfing, but it's too far to the beach, so we try surfing on land with the help of a volcano and some giant fans. Show more

We imagine becoming unbreakable by removing our bones, turning our skin to metal and finally by becoming completely elastic, but indestructibility isn't everything we hoped for. Show more

We try out a crazy idea from science fiction to build a giant sphere around the sun and give us more energy than we'll ever need.

Imagine removing all the colours one by one? It would change more than just how things look, and after taking out just three colours, we would not be able to see anything at all!