Just before this BBC podcast gets underway, here's something you may not know.

My name's Linda Davies and I Commission Podcasts for BBC Sounds.

As you'd expect, at the BBC we make podcasts of the very highest quality featuring the most knowledgeable

experts and genuinely engaging voices. What you may not know is that the BBC

makes podcasts about all kinds of things like pop stars,

poltergeist, cricket, and conspiracy theories and that's just a few examples.

If you'd like to discover something a little bit unexpected, find your next podcast over at BBC Sounds.

This is the BBC.

Thank you very much for downloading the shorter edition of more or less that first went out on the World Service on the 5th of May.

Just to let you know, if you've just listened to our previous podcast, which included an item about mazes. This is part two.

Hello and welcome to more or less on the BBC World Service.

We're your weekly guide to the numbers all around us and I'm Tim Harford.

This week a special edition all about the mathematics of losing yourself.

I'll leave you in the expert hands of more or less his aimlessly wandering around correspondent,

Jordan Dunbar. I've told him to get lost. There is moths built into everything around us, but more often than not we don't notice.

You don't walk into a building and think, wow, this is such a great navigational experience.

Or at least you don't unless you're Dr Ruth Dalton,

professor of building usability and visualization

at Northumbria University.

She spends a lot of time thinking about the maths of

navigation, which is why I joined her in the Barbican in London, a large housing estate in the city of London.

The Barbican plan to provide homes for 6,500 people in the heart of the city.

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