BBC Sounds, Music, Radio, Podcasts.

If you need help on money matters, you're not alone.

In the Martin Lewis podcast, I'll give you tips to keep more cash in your pocket

and answer your important questions.

Now that we're starting from scratch, what is the best way for us to move forward?

To help your everyday finances just add up. Let's see what we can do.

The Martin Lewis podcast, listen on BBC Sounds.

Hello and welcome to the documentary from the BBC World Service. I'm Misha Glennie,

and I'd like to alert you to the podcast I host in our time,

where expert guests discuss the ideas, people, events and discoveries that have shaped our world,

spanning history, religion, culture, science and philosophy, from why Silicon is a building block of our

universe to the wide-ranging

laws of the Babylonian King Hamarabi. And you can listen and subscribe to In Our Time,

wherever you found this podcast. On this episode, we explore the deepest oceanic trench on

Earth. In 1875 in the Western Pacific, the crew of HMS Challenger discovered the Mariana Trench,

which turned out to be deeper than Everest is high by some two kilometers.

Trenches like Mariana form when one tectonic plate slips under another and heads downwards towards the Earth's mantle.

There are around 50 of them globally.

Now, some people used to think that it was too dark and deep for life to exist down there,

while others imagined monsters lurking at the bottom of the ocean.

The truth has proved to be more intriguing than either of those.

Well, with me to discuss the Mariana Trench are three people who are all veterans of this

...