The series is a re-examination of some of the under-reported and darkest parts of American modern history using little known documents and newly uncovered archival material, looking beyond official versions of events to the deeper causes and implications and exploring how events from the past still have resonant themes for the present day. This episode addresses the historical backround, consequences and reasons behind the use of atomic bombs against the Japanese in the second world war.

August 6th 1945 marked the start of a terrifying new episode in human history. This documentary marks the 70th anniversary of the day when the world's first atomic bomb was dropped on the Japanese city of Hiroshima by a Boeing B-29 USAF Superfortress bomber, nicknamed Enola Gay after the pilot's mother". Up to 80,000 people - 30 per cent of the population - were killed by the blast and resulting firestorm and over 70,000 were injured. This documentary gives a minute-by-minute account of what happened on that fateful day, through the testimony of people who were there and rarely-seen archive footage from the time. Made on location in Hiroshima and the USA, it features unique interviews with eyewitnesses who have seldom, if ever, spoken about the experience. Several of them are no longer alive, they include the last surviving member of the crew of the Enola Gay - navigator Dutch Van Kirk who died in July 2014.

Richard Feynman is one of the most iconic, influential and inspiring scientists of the 20th century. He helped design the atomic bomb, solved the mystery of the Challenger Shuttle catastrophe and won a Nobel Prize. 25 years after his death - in his own words and those of his friends and family - this is the story of the most captivating communicator in the history of science.

Dr Janina Ramirez embarks on a journey through six decades of the BBC archives to create a television history of one of the most celebrated figures in art - Leonardo Da Vinci. Ramirez shows how experts and art presenters have turned to television to bring Leonardo's artwork out of galleries and into our living rooms. Through television they have explored the origins of Leonardo's boundless curiosity, his pioneering use of light and shade, and his remarkable scientific exploration.
Along the way Dr Ramirez discovers Britain's little-known version of The Last Supper, the gruesome ways Leonardo acquired his anatomical knowledge - and even what lies beneath the Mona Lisa.

Fly across iridescent tropical reefs, brush through a cloud of a million jellyfish, visit an alien world where the closer you look, the more you see, where the tiniest creatures support the greatest predators... We think of reefs as exotic, distant places with little or no connection to our everyday world. Yet every reef is a living city beneath the sea with a parallel existence to ours, distant yet undeniably connected. Reefs are hotspots of biodiversity as vital to life on earth as the rain-forests. They have been shaping our shorelines, literally forming islands and mountains, for millions of years. The fossil record shows that given time they have recovered from all of earth's major extinction events. Even reefs pulverised by atomic blasts at Bikini Atoll have regenerated. Yet within our lifetime reefs have come to face their greatest threat...

The simple act of making an apple pie is extrapolated into the atoms and subatomic particles (electrons, protons, and neutrons) necessary. Many of the ingredients necessary are formed of chemical elements formed in the life and deaths of stars (such as our own Sun), resulting in massive red giants and supernovae or collapsing into white dwarfs, neutron stars, pulsars, and even black holes. These produce all sorts of phenomena, such as radioactivity, cosmic rays, and even the curving of spacetime by gravity. Cosmos Update mentions the supernova SN 1987A and neutrino astronomy.