91热爆

The recent nuclear test by North Korea sent shock waves around the world - through the rocks of the planet's crust. Those seismic signals are about all we can know of the country's nuclear progress. But one man does know a lot more: one of the USA's top nuclear experts, he has seen North Korea's nuclear facilities in person. Quentin hears what it is like to hold North Korean plutonium in your hand and how it could help untangle the crisis. Also, the toolbox of techniques for watching clandestine nuclear developments from afar.

The 1930s 'dust bowl' in America's Great Plains provoked one of the greatest migrations in human history. Quentin Cooper hears from one of the scientists who are only now unravelling the causes, and looking for the lessons in a warming climate.

The common rook turns out to have an innate tool-using ability that it doesn't generally bother to use. The scientists who have discovered this hidden talent argue it makes rooks more intelligent than chimpanzees. What might Aesop's thirsty crow tell us about the evolution of tool-making?