Thank you for downloading this episode of a history of the world in a hundred objects from BBC Radio 4.

I've got the whole world in my hands. In fact not just the world but the

Cosmos. What I'm holding is a portable model of the heavens in the shape of an exquisite circular brass instrument

that looks a bit like a large brass pocket watch and it's called an ast. astronaut. With an astrolabe in my hands I can tell the time, do a bit of surveying, work out my position in the world by sun or stars and if that's not enough I can also devise

my horoscope. Although perfectly familiar to the ancient Greeks this was an

instrument that was particularly important for the Islamic world as it allowed the faithful

to find the direction of Mecca.

And so it's not surprising that the oldest astrolabe to survive is an Islamic one from

the 10th century.

But the astralab I'm holding is in fact a Jewish one.

It was made about 750 years ago in Spain.

It's inscribed in Hebrew lettering, but it contains Arabic and Spanish words, and it combines

both Islamic and European decorative elements.

It's not just an advanced scientific instrument,

it's also an emblem of a very particular moment

in Europe's religious and political history.

There's a Spanish word that's often used to describe the relationship between the different religions and ethnic communities,

it is conviventia living together.

The astelbe is much more than just a scientific instrument. It's also a symbol of knowledge.

It symbolizes that one understands what's going on in the heavens.

One literally holds the latest knowledge in one's hands.

So it has so many functions, it really is like a medieval type of blackberry.

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