Catch up TV
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!
Source: CBBC
Most recent episodes of Hey You What If?
Hey You What If?
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!
25-04-2024
CBBC
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.
22-03-2024
CBBC
Hey You What If?
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!
21-03-2024
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?
20-03-2024
CBBC
Hey You What If?
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..
19-03-2024
CBBC
Hey You What If?
Series 2: 11. Animals Were Supersized
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.
18-03-2024
CBBC
Hey You What If?
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
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.
15-03-2024
CBBC
Hey You What If?
Series 2: 9. We Had Two Suns
There is a way that Earth could have a second sun, so we try it out to see what happens.
14-03-2024
CBBC
Hey You What If?
Series 2: 8. You Were Invisible
We try out three potential ways to become invisible and discover some surprising side effects.
13-03-2024
CBBC
Most popular episodes of Hey You What If?
Hey You What If?
Series 1: 17. You Could Live In Slow Motion?
Find out why living in slow motion would let you see things no-one else can!
01-11-2023
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.
11-03-2024
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!
06-11-2023
CBBC
Hey You What If?
Series 1: 5. You Could Go On Holiday To Mars?
Experience the ultimate in long-distance travel - a holiday on Mars!
02-02-2024
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.
12-03-2024
CBBC
Hey You What If?
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
Hey You What If?
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
Hey You What If?
Series 1: 4. You Could Turn Into A Giant?
Find out why turning into a huge giant would be no fairy tale.
30-01-2024
CBBC
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.
22-03-2024
CBBC
Hey You What If?
Series 1: 9. The Moon Was Made Of Cheese?
Things don’t quite go to plan when the moon turns into cheese.
21-12-2023
CBBC