Hey You! What If...

All Episodes 2020 - 2022

  • 2018-01-12T08:15:00Zs at 2018-01-12T08:15:00Z on CBBC
  • 2020-03-02T08:15:00Z
  • 5m
  • 4h 20m (52 episodes)
  • United Kingdom
  • English
Comedy science series for children aged 6 and over made to blow your mind, one question at a time!

52 episodes

Series Premiere

2020-03-02T08:15:00Z

1x01 You Fell Into a Black Hole?

Series Premiere

1x01 You Fell Into a Black Hole?

  • 2020-03-02T08:15:00Z5m

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

1x02 You Could Dig Through the Earth?

  • 2020-03-03T08:15:00Z5m

The deepest hole humankind ever dug only got one thousandth of the way through the earth. But what would happen if you kept digging?

1x03 You Could Take a Lift to Space?

  • 2020-03-04T08:15:00Z5m

What would happen if there really was a lift that took you all the way up to space?

1x04 You Could Turn into a Giant?

  • 2020-03-05T08:15:00Z5m

Find out why turning into a huge giant would be no fairy tale.

1x05 You Could Go on Holiday to Mars?

  • 2020-03-06T08:15:00Z5m

Experience the ultimate in long-distance travel - a holiday on Mars!

2020-03-09T08:15:00Z

1x06 You Could Levitate?

1x06 You Could Levitate?

  • 2020-03-09T08:15:00Z5m

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

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

1x08 The Earth Stopped Spinning?

  • 2020-03-11T08:15:00Z5m

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

1x09 The Moon Was Made of Cheese?

  • 2020-03-12T08:15:00Z5m

Things don’t quite go to plan when the moon turns into cheese.

2020-03-13T08:15:00Z

1x10 The Earth Was Flat?

1x10 The Earth Was Flat?

  • 2020-03-13T08:15:00Z5m

Find out why a flat Earth would feel very unflat indeed!

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

1x12 You Can't Wait for Christmas?

  • 2020-03-17T08:15:00Z5m

It really is possible to time travel into the future, and the team show you how!

1x13 You Could Shrink Yourself?

  • 2020-03-18T08:15:00Z5m

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

1x14 You Could Live on the Moon?

  • 2020-03-19T08:15:00Z5m

Some day people will live on the moon – find out just what they are in for.

What if you could turn things to gold? This episode shows that it might not work out that well.

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

1x17 You Could Live in Slow Motion?

  • 2020-03-24T08:15:00Z5m

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

Would it be possible to live on an Earth shaped like a doughnut? You might be surprised!

A fun run goes wrong when one ambitious runner tries running at the speed of sound.

1x20 You Try to Catch a Falling Star?

  • 2020-03-27T08:15:00Z5m

What happens if you try to catch a falling star? Spoiler alert - probably best not to try!

Why waking up with lizard powers would make you useless on earth but a superhero in space!

It’s the ultimate baking challenge: making a gingerbread house you could actually live in.

2020-05-06T07:15:00Z

1x23 You Could Teleport?

1x23 You Could Teleport?

  • 2020-05-06T07:15:00Z5m

Is it really possible to teleport? Spoiler alert: it could end in disaster!

Empty the oceans and you’d see hidden wonders, but you’d also cause the end of the world.

1x25 You Could Switch Off the Sun?

  • 2020-05-08T07:15:00Z5m

See what would happen if you really could switch off the sun.

Season Finale

2020-05-11T07:15:00Z

1x26 You Could Fly Like a Bird?

Season Finale

1x26 You Could Fly Like a Bird?

  • 2020-05-11T07:15:00Z5m

Anyone can fly like a bird – you just have to travel across the solar system to do it!

Season Premiere

2022-09-05T07:15:00Z

2x01 You Built a Mega Slide?

Season Premiere

2x01 You Built a Mega Slide?

  • 2022-09-05T07:15:00Z5m

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.

2022-09-06T07:15:00Z

2x02 You Walked Through Walls?

2x02 You Walked Through Walls?

  • 2022-09-06T07:15:00Z5m

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.

2022-09-07T07:15:00Z

2x03 We Got Rid of Bugs?

2x03 We Got Rid of Bugs?

  • 2022-09-07T07:15:00Z5m

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.

2022-09-08T07:15:00Z

2x04 You Needed Two of You?

2x04 You Needed Two of You?

  • 2022-09-08T07:15:00Z5m

From cloning to 3D printing, what if we could actually make copies of ourselves?

2x05 You Could Stop Global Warming?

  • 2022-09-12T07:15:00Z5m

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 and could cause an ice age.

2022-09-13T07:15:00Z

2x06 You Lived on Venus?

2x06 You Lived on Venus?

  • 2022-09-13T07:15:00Z5m

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.

2x07 You Could Shout Round the World?

  • 2022-09-14T07:15:00Z5m

Find out how to shout from one side of the world to the other.

2022-09-15T07:15:00Z

2x08 You Were Invisible?

2x08 You Were Invisible?

  • 2022-09-15T07:15:00Z5m

We try out three potential ways to become invisible and discover some surprising side effects.

2022-09-16T07:15:00Z

2x09 We Had Two Suns?

2x09 We Had Two Suns?

  • 2022-09-16T07:15:00Z5m

There is a way that Earth could have a second sun, so we try it out to see what happens.

2x10 Your Mind Could Move Things?

  • 2022-09-19T07:15:00Z5m

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 expect.

2022-09-20T07:15:00Z

2x11 Animals Were Supersized?

2x11 Animals Were Supersized?

  • 2022-09-20T07:15:00Z5m

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.

2x12 You Walked on the Ceiling?

  • 2022-09-21T07:15:00Z5m

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.

What would the planet be like if all other humans disappeared, leaving you as the last person on earth?

2x14 You Built a Giant Sand Castle?

  • 2022-09-23T07:15:00Z5m

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.

2022-09-26T07:15:00Z

2x15 You Shrunk the Earth?

2x15 You Shrunk the Earth?

  • 2022-09-26T07:15:00Z5m

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.

2022-09-27T07:15:00Z

2x16 Money Grew on Trees?

2x16 Money Grew on Trees?

  • 2022-09-27T07:15:00Z5m

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.

2x17 You Flew Like a Superhero?

  • 2022-09-28T07:15:00Z5m

Flying like a superhero may sound like enormous fun, but there are some serious downsides that Hollywood does not tell you about - weather, extreme cold and even fizzy blood.

2022-09-29T07:15:00Z

2x18 There Were No Colours?

2x18 There Were No Colours?

  • 2022-09-29T07:15:00Z5m

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.

2022-09-30T07:15:00Z

2x19 You Only Ate Burgers?

2x19 You Only Ate Burgers?

  • 2022-09-30T07:15:00Z5m

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 we need.

2x20 You Threw a Ball Round the World?

  • 2022-10-03T07:15:00Z5m

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.

We reveal how to create the ultimate in tall buildings by going to the moon and taking inspiration from wedding cakes.

2022-10-05T07:15:00Z

2x22 You Had Kangaroo Legs?

2x22 You Had Kangaroo Legs?

  • 2022-10-05T07:15:00Z5m

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?

2022-10-06T07:15:00Z

2x23 You Were Indestructible?

2x23 You Were Indestructible?

  • 2022-10-06T07:15:00Z5m

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.

2022-10-07T07:15:00Z

2x24 You Surfed Without Water?

2x24 You Surfed Without Water?

  • 2022-10-07T07:15:00Z5m

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.

2022-10-10T07:15:00Z

2x25 Earth Ran Out of Energy?

2x25 Earth Ran Out of Energy?

  • 2022-10-10T07:15:00Z5m

We try out a crazy idea from science fiction to build a giant sphere around the sun and give us more energy than we'll ever need.

Season Finale

2022-10-11T07:15:00Z

2x26 You Could Walk Up Walls?

Season Finale

2x26 You Could Walk Up Walls?

  • 2022-10-11T07:15:00Z5m

We take inspiration from the natural world as we imagine a new kind of superhero that can walk up walls.

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