Echolocation

In Our Time | 21 June 2018 | 0h 51m | Listen Later  | iTunes
Melvyn Bragg and guests discuss how some bats, dolphins and other animals emit sounds at high frequencies to explore their environments, rather than sight. Bats that echolocate have a range of frequencies for different purposes and techniques for preventing themselves from becoming deafened by their own sounds. Some prey have evolved ways of detecting when bats are emitting high frequencies in their direction, and some fish have adapted to detect the sounds dolphins use to find them.

Matt Ridley on Climate Change

EconTalk | 29 June 2015 | 1h 08m | Listen Later  | iTunes
Interview on climate change with science writer and author Matt Ridley, who describes himself as a “lukewarmer.” While Ridley agrees that humans have made the climate warmer, he argues that the impact is small or positive over some temperature ranges and regions. He rejects the catastrophic scenarios that some say are sufficiently likely to justify dramatic policy responses, and he reflects on the challenges of staking out an unpopular position on a contentious policy issue.