An examination of the heavy metal music subculture that tries to explain why, despite the longevity and popularity of the genre, fans are marginalized and ridiculed for their passion.
Sam Dunn is a anthropologist and a lifelong metal fan. After years of studying diverse cultures, Sam turns his academic eye a little closer to home and embarks on an epic journey into the heart of heavy metal. His mission: to figure out why metal music is consistently stereotyped, dismissed and condemned, even while the tribe that loves it stubbornly holds its ground -- spreading the word, keeping the faith and adopting styles and attitudes that go way beyond the music.
Sam visits heavy metal landmarks as far flung as L.A.'s Sunset Strip, the dirty streets of Birmingham and the dark forests of Norway. Along the way, the two sides of Sam Dunn -- curious anthropologist and rabid fan -- collide, as Sam explores metal's obsession with sex, religion, violence and death, meets his heroes, and discovers some things about the culture that even he can't defend.

In the early 1970s, Sixto Rodriguez was a Detroit folksinger who had a short-lived recording career with only two well received but non-selling albums. Unknown to Rodriguez, his musical story continued in South Africa where he became a pop music icon and inspiration for generations. Long rumored there to be dead by suicide, a few fans in the 1990s decided to seek out the truth of their hero's fate. What follows is a bizarrely heartening story in which they found far more in their quest than they ever hoped, while a Detroit construction labourer discovered that his lost artistic dreams came true after all.

Dr Hannah Fry explores a paradox at the heart of modern maths, discovered by Bertrand Russell, which undermines the very foundations of logic that all of maths is built on. These flaws suggest that maths isn't a true part of the universe but might just be a human language - fallible and imprecise. However, Hannah argues that Einstein's theoretical equations, such as E=mc2 and his theory of general relativity, are so good at predicting the universe that they must be reflecting some basic structure in it. This idea is supported by Kurt Godel, who proved that there are parts of maths that we have to take on faith.
Hannah then explores what maths can reveal about the fundamental building blocks of the universe - the subatomic, quantum world. The maths tells us that particles can exist in two states at once, and yet quantum physics is at the core of photosynthesis and therefore fundamental to most of life on earth - more evidence of discovering mathematical rules in nature. But if we accept that maths is part of the structure of the universe, there are two main problems: firstly, the two main theories that predict and describe the universe - quantum physics and general relativity - are actually incompatible; and secondly, most of the maths behind them suggests the likelihood of something even stranger - multiple universes.
We may just have to accept that the world really is weirder than we thought, and Hannah concludes that while we have invented the language of maths, the structure behind it all is something we discover. And beyond that, it is the debate about the origins of maths that has had the most profound consequences: it has truly transformed the human experience, giving us powerful new number systems and an understanding that now underpins the modern world.

Every summer in the seas off Alaska humpback whales, sea lions and killer whales depend on an explosion of plant life, the plankton bloom. It transforms these seas into the richest on Earth. But will these animals survive to enjoy the great feast? The summer sun sparks the growth of phytoplankton, microscopic floating plants which can bloom in such vast numbers that they eclipse even the Amazon rainforest in sheer abundance of plant life. Remarkably, it is these minute plants that are the basis of all life here. But both whales and sea lions have obstacles to overcome before they can enjoy the feast. Humpback whales migrate 3,000 miles from Hawaii, and during their 3 month voyage lose a third of their body weight. In a heart-rending scene a mother sea lion loses her pup in a violent summer storm, while another dramatic sequence shows a group of killer whales working together to kill a huge male sea lion.
In late summer the plankton bloom is at its height. Vast shoals of herring gather to feed on it, diving birds round the fish up into a bait ball and then a humpback whale roars in to scoop up the entire ball of herring in one huge mouthful. When a dozen whales work together they employ the ultimate method of co-operative fishing - bubble net feeding. One whale blows a ring of bubbles to engulf the fish and then they charge in as one. Filmed from the surface, underwater and, for the first time, from the air, we reveal how these giant hunters can catch a tonne of fish every day.

The great flood in the Okavango turns 4,000 square miles of arid plains into a beautiful wetland. Elephant mothers guide their families on an epic trek across the harsh Kalahari Desert towards it, siphoning fresh water from stagnant pools and facing hungry lions. Hippos battle for territory, as the magical water draws in thousands of buffalo and birds, and vast clouds of dragonflies. Will the young elephant calves survive to reach this grassland paradise? The experienced mother elephants time their arrival at the delta to coincide with the lush grass produced by the great flood.
In a TV first, the programme shows the way they use their trunks to siphon clean water from the surface layers of a stagnant pool, while avoiding stirring up the muddy sediment on the bottom with their feet. Lechwe swamp deer, zebras, giraffes, crocodiles and numerous fish and thousands of birds arrive in the delta. And, in a phenomenon never before filmed in the Okavango, thousands of dragonflies appear - seemingly from nowhere - within minutes of the flood arrival, mating and laying eggs. As the flood finally reaches its peak, elephants and buffalo, near the end of their epic trek across the desert, face the final gauntlet of a hungry pride of lions. In a heart-wrenching sequence, a baby elephant is brought down by a lion in broad daylight.

Growing up. Finding food. Seeking shelter. Finding a soul mate. Raising children. These universal themes touch the hearts of audiences everywhere. Parents will do anything to give their kids the best start in life. Witness the epic journey of a tiny poison arrow frog, scaling impossibly high trees to feed her tadpoles in the canopy. As the young grow, they confront the life long search for food. Capuchin monkeys spend up to eight years teaching their young the complex process of preparing a palm nut meal.
For those creatures who successfully negotiated all the obstacles to adulthood, it’s time to face the ultimate test: to find a partner and to pass on their genes to the next generation. In what is one of the most spectacular and romantic courtship dances in the world, grebes step out across the surface of a lake in perfect unison. We see so much of ourselves in these different animals, and them in us – intelligence, strength, determination, courage, even love. The stories combine to reveal how every living thing on our planet shares the same desire – not just to live, but to foster new life. Relevant, engaging and above all, amazing. Narrated by Daniel Craig,