Hello, I'm Martin Rees. Thank you for downloading this podcast of the 2010 Reith Lectures from the BBC.

You can find out more, listen again, read transcripts and subscribe to the podcast at BBC.co.com.

com slash Reith Lectures.

Hello and welcome to the radio theatre in Broadcasting House for the first in this year's series of Reith lectures.

They're being given by a man who's been called a scientific magician, a man who leaves you wondering where he got his ideas from.

Magic, however, is not his business. He's rooted in the pursuit of

rigorous scientific inquiry, and his work has taken him to the pinnacle of his profession,

as president of the Royal Society, Astronomer Royal, and Master of Trinity College, Cambridge.

He's called his four lectures, Scientific horizons. His subject is the challenges

and threats man faces as he starts his journey through the rest of the 21st century. He believes

we're in danger, as he puts it, of destroying the book of life before we've read it. Man may be at the

top of the evolutionary tree,

but there are still many things he doesn't understand

and possibly never will.

Indeed, the form of life of which he's a part

may not be the only one in the universe.

So in scientific horizons,

our lecturer will look at the threats

to the whole existence of man

and explore some of their solutions.

Ladies and gentlemen, please welcome the BBC's Reith Lecturer 2010, Martin Rees.

Welcome. Welcome, Martin. You've been astronomer royal for the past 15 years, I think. I gather it's a deeply arduous task.

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