What time was the first clock set to?

From sundials to atomic clocks via Big Ben, a quest into the history of timekeeping.

• 27 mins

Why do we have wisdom teeth?

Answering your questions about life, Earth and the universe

• 28 mins

How bad is our data for the planet?

What's the environmental impact of all the data we use?

• 27 mins

Do we all see the same colour?

Caroline Steel investigates what affects the way we see the colours of the world

• 29 mins

Is the BMI fatphobic?

How useful is the Body Mass Index?

• 29 mins

Do animals have anxious habits like us?

Why do we bite our nails - and do animals share similar habits?

• 27 mins

Could climate change lead to more volcanic eruptions?

We head to New Zealand to ask how a hotter planet will affect volcanoes.

• 27 mins

How many people have ever existed?

Listener Alpha in Sierra Leone asks us to count all the humans who have ever lived

• 26 mins

How do my ears sense direction?

How can we hear a sound and immediately know where it’s coming from?

• 32 mins

Are our coastlines being washed away?

What is coastal erosion and why is it a problem?

• 26 mins

How should we protect our coastlines?

What’s the best way to combat coastal erosion?

• 26 mins