Hey You What If? Catch up, Series 1: 1. You Fell Into a Black Hole? on CBBC

Hey You What If?

Series 1: 1. You Fell Into a Black Hole?

Experience the most extraordinary ride in the universe – falling into a black hole.

Source: CBBC

Most recent 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.

20-04-2026

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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!

27-03-2026

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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?

26-03-2026

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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..

25-03-2026

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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.

24-03-2026

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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.

23-03-2026

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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.

20-03-2026

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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.

19-03-2026

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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.

18-03-2026

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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.

17-03-2026

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