Hello and welcome to Babbage from Economist Radio, our weekly podcast on technology and science.

I'm Kenneth Cuckier, a senior editor at The Economist.

And coming up on today's show, a guided tour of the planet Mars.

Mars is, as you may have noticed, very cold. The atmosphere is terribly thin. Being at sea level,

but there are no seas, is like being in the stratosphere of the Earth.

And what can statisticians tell us about the arts? We meet the researchers at cataloging

culture.

We were able to trace the changing meaning of some words in ancient Greek that scholars

had spent many years studying.

But first, our correspondent Noah Snyder traveled to one of the most remote places on Earth

to talk to the scientist who's on a mission to slow the thawing of the Arctic.

Last summer, I went to the Russian Arctic to meet with a man named Sergei Zimov.

He's got this long gray beard, this long gray hair, these intense, gray blue eyes.

He took me one day down the Colombo River we bounced in, a rickety motorboat for a few

hours until we got to a cliff side of frozen ground that they call permafrost.

As we were standing there on this cliff side, mammoth bones were sticking from the mud.

There were sort of old plant and animal remains strewn across the banks of this river.

Sergei turned to me and said, to be a prophet, you must live in the desert.

I really come to see Sergei in a way as a prophet of the permafrost.

Nearly a quarter of the northern hemisphere were talking about an area that's twice the

size of America.

Sits on top of ground, it's made up of soil which remains frozen for at least two years

...