While scientists have previously theorised about a “Big Crunch” where the universe retracts back to its original size, the discovery of Dark Matter and Dark Energy has placed that hypothesis on the backburner. Some astronomers now believe that if Dark Matter offsets Dark Energy then as the universe slowly expands, stars will gradually fade, running out of fuel and leading to a dark, cold and lifeless universe. Others hypothesise a much more violent end where Dark Energy continues to expand the universe at a greater and greater speed. Stronger than gravity, Dark Energy would pull apart everything down to the fundamental particles – the universe’s very fibres. While the universe’s end may be 50 billion years away, great leaps in science will continue to alter how we believe the universe was formed – and how it will end.

Memory is the glue that binds our mental lives. Without it, we’d be prisoners of the present, unable to use the lessons of the past to change our future. From our first kiss to where we put our keys, memory represents who we are and how we learn and navigate the world. But how does it work? Neuroscientists using cutting-edge techniques are exploring the precise molecular mechanisms of memory". By studying a range of individuals ranging —from an 11-year-old whiz-kid who remembers every detail of his life to a woman who had memories implanted— scientists have uncovered a provocative idea. For much of human history, memory has been seen as a tape recorder that faithfully registers information and replays intact. But now, researchers are discovering that memory is far more malleable, always being written and rewritten, not just by us but by others. We are discovering the precise mechanisms that can explain and even control our memories. The question is— are we ready?

This episode examines the idea of scientific racism, an ideology invented during the 19th century that drew on now discredited practices such as phrenology and provided an ideological justification for racism and slavery. The episode shows how these theories ultimately led to eugenics and Nazi racial policies of the master race.

In 2000, Bill and Hillary Clinton owed millions of dollars in legal debt. Since then, they’ve earned over $130 million. Where did the money come from? Most people assume that the Clintons amassed their wealth through lucrative book deals and high-six figure fees for speaking gigs. Now, Peter Schweizer shows who is really behind those enormous payments. He detailed patterns of official corruption in Washington that led to congressional resignations and new ethics laws. He follows the Clinton money trail, revealing the connection between their personal fortune, their “close personal friends,” the Clinton Foundation, foreign nations, and some of the highest ranks of government.

Sam Neill explores humanity's long-term future - a future where we make new homes for ourselves on other worlds as we flee from the slow but inevitable death of our sun.

In 1985, two adventurous young mountaineers, Joe Simpson and Simon Yates, set off to climb the treacherous west face of the Siula Grande in the Peruvian Andes. They were experienced climbers, and climbed "Alpine-style," climbing the mountain in "one great push," without setting up ropes or base camps ahead of time. After dealing with a snowstorm and some dangerous climbing over powder formations, they reached the summit (about 21,000 feet) on the third day. The climb down proved to be far more difficult. Simpson fell and broke his leg badly. Yates decided to try to lower Simpson down the mountain, one 300-foot section of rope at a time. The climbers had run out of gas to melt snow, so they couldn't risk stopping as night came, and a violent snowstorm began. Their plodding, painful journey hit a snag when Yates inadvertently lowered Simpson over the edge of a cliff. In the storm, the men couldn't hear each other's cries, and, Yates, uncertain as to Simpson's position, and gradually sliding down the slope himself, decided to cut the rope that connected them, sending Simpson plummeting to certain death. Miraculously, Simpson survived the fall, and was faced with the prospect of getting off the mountain alone with no food, no water, and a broken leg. In Touching the Void, filmmaker Kevin Macdonald (One Day in September) tells their story, based on Simpson's book, using contemporary interviews with the two men, and a reenactment of their climb and descent, featuring Brendan Mackey as Simpson and Nicholas Aaron as Yates