The fourth episode of podcast the From the Moon titled The World at Night is dedicated to the theme of the night. Darkness allows us to see the twinkling lights of cities, industries and infrastructure - virtually all human activities since the invention of electricity. This episode offers different points of view, a look at the cities, from urban planning to the impact of light pollution on the environment, up to conceiving the night as a cultural opportunity.

We will continue to observe the world, this time seeing the surface of the planet as it faces away from the sun. The darkness allows us to see the sparkling lights of cities, of industry and of infrastructure, virtually all human activity since the invention of electricity, scarcely 150 years ago - is lit up for us.  As people down there on Earth switch on, consume and eventually - sleep, all the millions of individual lights of the streets and cities which they inhabit merge to create a radiating map of the world.

David Plaisant first gets a night time overview of the cities of Europe, Africa, Asia and North America with Ricky Burdett before looking into (or trying to understand at least) the darkness with Angela Rui. We then hear from Joni Baboci on the shape of cities and how (and when) they might stop growing; finally from Hanru Hou we find out about the cultural opportunity the night represents and how freedom often comes after dark.