We routinely talk about healthy food and clean water, but how often do we spare a thought for what enters our lungs? The World Health Organization calls air pollution the silent killer. Air pollution is proven to shorten our lifetimes and it hits the vulnerable - children, the sick and the elderly - hardest of all.
Prince William, Sir David Attenborough and astronaut Naoko Yamazaki hear the personal stories of people who are directly affected by air pollution and show us incredible solutions.

Carter's dreams of change give way to Ronald Reagan. Gorbachev redeems Reagan and fresh opportunities for peace arise. The debate over Reagan's legacy.

From virtually the moment we're born, there's a story that's preached across cultures and continents. It's a familiar fairy tale, that finding one true love is the key to a fulfilled and happy life. As an adult, we're forced to reconcile the messaging on monogamy with one simple fact: humans are terrible at it.
What do biology, human history and the promiscuity of bonobos reveal about monogamy? Experts and everyday couples weigh in on shifting cultural norms.

This episode explores what can give brains a boost. In America, Angela tries out a new treatment that's proven to help memory and concentration. In Japan, a remarkable 100-year-old reveals the colourful foods that keep minds more active. Plus Chris discovers the best exercise we can do for our brains. At the cutting-edge of science, discover how injections of young people's blood may help beat dementia.

In the last episode of the series, Freeman examines different faiths' views on miracles, meeting a man who survived falling 47 storeys and a cancer patient who believes his illness can be cured by prayer.

The universe began with a massive expansion, billions and billions of years ago, and it continues to expand with every passing second. The idea that the universe, and man's very existence, began with a "Big Bang" is no longer a topic of debate among most scientists--it is essentially taken as fact.