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?

Is it possible to build a sand castle the size of a real castle? We imagine how it could be done, using a pneumatic drill and a huge, solid gold steamroller!

We try using a gravity-bending black hole and spinning the earth faster to see if we can make it possible to walk on the ceiling..

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.

Clouds might look like cotton wool, but if they really were, things would get very messy.

Good news - it’s possible to levitate! Bad news – there are some serious side effects.

Find out why stopping the Earth from spinning isn’t such a good idea.

If you have always wanted to shrink yourself, this is the episode for you!

The planet is being destroyed - but this episode demonstrates the things you can do to help save it.

Find out why living in slow motion would let you see things no-one else can!

Want to reach for the stars? It would be the journey of a lifetime - literally.

To win a marathon, are you better off with the bouncing legs of a kangaroo, the long legs of a T rex or sticking with the legs of a human? Show more

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