Catch up TV
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.
Source: CBBC
Most recent episodes of Hey You What If?
Hey You What If?
Series 1: 24. You Took All The Water Out Of The Sea?
Empty the oceans and you’d see hidden wonders, but you’d also cause the end of the world.
05-11-2024
CBBC
Hey You What If?
Series 1: 23. You Could Teleport?
Is it really possible to teleport? Spoiler alert: it could end in disaster!
29-10-2024
CBBC
Hey You What If?
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 ...
25-10-2024
CBBC
Hey You What If?
Series 1: 22. You Could Build A Gingerbread House?
It’s the ultimate baking challenge: making a gingerbread house you could actually live in.
22-10-2024
CBBC
Hey You What If?
Series 2: 20. You Threw A Ball Round The World
To throw a ball around the world, you need to start out in space, throw it ten times the speed of a bullet and make sure your ball does not explode when it hits the atmosphere.
18-10-2024
CBBC
Hey You What If?
Series 1: 21. You Woke Up As A Lizard Superhero?
Why waking up with lizard powers would make you useless on earth but a superhero in space!
15-10-2024
CBBC
Hey You What If?
Series 2: 19. You Only Ate Burgers
If everyone in the world ate nothing but cheeseburgers, we would run out of land, and even if we went meat-free, we would have to invent some crazy burgers to get the nutrients ...
11-10-2024
CBBC
Hey You What If?
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
Hey You What If?
Series 2: 13. You Were The Last Person On Earth
What would the planet be like if all other humans disappeared, leaving you as the last person on earth?
06-10-2024
CBBC
Hey You What If?
Series 2: 18. There Were No Colours
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!
04-10-2024
CBBC
Most popular episodes of Hey You What If?
Hey You What If?
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.
02-09-2024
CBBC
Hey You What If?
Series 2: 19. You Only Ate Burgers
If everyone in the world ate nothing but cheeseburgers, we would run out of land, and even if we went meat-free, we would have to invent some crazy burgers to get the nutrients ...
11-10-2024
CBBC
Hey You What If?
Series 2: 13. You Were The Last Person On Earth
What would the planet be like if all other humans disappeared, leaving you as the last person on earth?
06-10-2024
CBBC
Hey You What If?
Series 2: 6. You Lived On Venus
Venus has acid rain, crushing pressure, and is hotter than an oven, so it might not sound like the ideal place to live. However, up in the clouds it's almost just like home.
09-09-2024
CBBC
Hey You What If?
Series 2: 4. You Needed Two Of You
From cloning to 3D printing, what if we could actually make copies of ourselves?
03-10-2024
CBBC
Hey You What If?
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
Hey You What If?
Series 2: 16. Money Grew On Trees
If you had a tree that could grow money, would that make you rich? Even if you wait 20 years for your tree to grow, you will probably end up no richer than you started.
04-09-2024
CBBC
Hey You What If?
Series 2: 7. You Could Shout Round The World
Find out how to shout from one side of the world to the other.
10-09-2024
CBBC
Hey You What If?
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.
04-10-2024
CBBC
Hey You What If?
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.
13-09-2024
CBBC