
So you want to build the tallest building on Earth? Ambitious but good on yer! This episode will tell you how, starting with how not to. \n\nMost tall buildings are tall and thin because land is expensive. But this isn’t the best design because the lowest floor has to take the weight of all the floors above it. And so eventually, you reach a limit where the structure at the bottom isn’t strong enough. \n\nIf you want to make a building significantly higher, then you need to change the shape and instead take inspiration from wedding cakes. The bottom layers of a wedding cake get wider and wider, which means that they can take more and more weight. In fact, the tallest building ever conceived, the X-Seed 4000, is 4km high and can house a million people - but it’s never been built. \n\nHowever, even if you made a giant cone-shaped building, and assuming you have materials that are strong enough, then eventually you would reach another limit, when the weight of the building is too much for the ground below. That’s why mountains have a maximum size. So, if you want to go higher still, you need to go to the moon, where gravity is lower and so you can go six times higher. But then that wouldn’t be the tallest building on Earth, would it?!
Source: CBBC
Series 1: 12. You Can't Wait For Christmas?
It really is possible to time travel into the future, and the team show you how!
21-12-2025
CBBC
Series 2: 14. You Built A Giant Sandcastle
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!
27-11-2025
CBBC
Series 1: 2. You Could Dig Through The Earth?
The deepest hole humankind ever dug only got one thousandth of the way through the earth. But what would happen if you kept digging?
13-11-2025
CBBC
Series 1: 6. You Could Levitate?
Good news - it’s possible to levitate! Bad news – there are some serious side effects.
29-10-2025
CBBC
Series 2: 5. You Could Stop Global Warming
Imagine if we had a thermostat that could turn the world temperature down - could we fix global warming? But be careful, a few degrees too far could cause an ice age.
24-10-2025
CBBC
Series 2: 4. You Needed Two Of You
From cloning to 3D printing, what if we could actually make copies of ourselves?
23-10-2025
CBBC
Series 2: 3. We Got Rid Of Bugs
Bugs might be annoying, but we would soon regret it if we got rid of them - all our favourite foods would disappear, and there would be dung everywhere!
22-10-2025
CBBC
Series 2: 2. You Walked Through Walls
Wouldn't it be cool to be able to walk through walls? From turning into a gas to quantum trickery, we discover why it wouldn't be quite as useful as you'd like.
21-10-2025
CBBC
Series 2: 1. You Built A Mega Slide
Could you build a slide to the other side of the world? You would need to start in space, use the slippiest slide ever and make sure you have enough supplies before you go down it!
20-10-2025
CBBC
Series 1: 1. You Fell Into A Black Hole?
Experience the most extraordinary ride in the universe – falling into a black hole.
11-07-2025
CBBC
Series 1: 15. Everything You Touched Turned To Gold?
What if you could turn things to gold? This episode shows that it might not work out that well.
30-10-2023
CBBC
Series 2: 10. Your Mind Could Move Things
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.
16-05-2025
CBBC
Series 2: 12. You Walked On Ceilings
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..
20-05-2025
CBBC
Series 2: 26. You Could Walk Up Walls
We take inspiration from the natural world as we imagine a new kind of superhero that can walk up walls.
15-03-2024
CBBC
Series 2: 15. You Shrunk The 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.
23-05-2025
CBBC
Series 2: 21. You Built The Tallest Building On Earth
So you want to build the tallest building on Earth? Ambitious but good on yer! This episode will tell you how, starting with how not to. \n\nMost tall buildings are tall and th ...
16-06-2025
CBBC
Series 1: 2. You Could Dig Through The Earth?
The deepest hole humankind ever dug only got one thousandth of the way through the earth. But what would happen if you kept digging?
13-11-2025
CBBC
Series 1: 20. You Try To Catch A Falling Star?
What happens if you try to catch a falling star? Spoiler alert - probably best not to try!
08-10-2024
CBBC
Series 1: 14. You Could Live On The Moon?
Some day people will live on the moon – find out just what they are in for.
01-08-2024
CBBC
Series 1: 11. We Could Actually Stop Climate Change?
The planet is being destroyed - but this episode demonstrates the things you can do to help save it.
24-10-2023
CBBC