At critical moments in history, our second place metal was the most important metal on Earth. Big History reveals how silver's place in our minds was determined by the heat of exploding stars, and how this one metal saved democracy.
Following 161 84 views About Export Add to From the Great Pyramid at Giza to the towering skyscrapers of today, humans have engineered massive constructions for at least 5,000 years. But why? How do biology and human emotions affect our desire to build gigantic structures?
2013 • Nature
Thanks to new technologies combining genetics, ethology, geology and even particle physics, paleontologists can now recreate the missing branches of the tree of life. Now, paleontologists can show that there were far more feathered dinosaurs than previously believed.
This programme focuses on birds. The feather is key to everything that is crucial about a bird: it is both its aerofoil and its insulator. The earliest feathers were found on a fossilised Archaeopteryx skeleton in Bavaria. However, it had claws on its wings and there is only one species alive today that does so: the hoatzin, whose chicks possess them for about a week or so. Nevertheless, it serves to illustrate the probable movement of its ancestor. It may have taken to the trees to avoid predators, and over time, its bony, reptilian tail was replaced by feathers and its heavy jaw evolved into a keratin beak.
Huge changes have swept across Arabia since the discovery of oil and the Arab relationship with nature has changed too. This is summed up by the changes to camel racing, now an ultra hi-tech sport. Arabia's animals now live alongside a very modern society but Arabia's people are using technology to protect nature: dugongs are fitted with satellite transmitters; hunting falcons chase down radio-controlled planes and the world's first carbon-neutral city is being built in the very heart of oil country.
The Comb-crested Jacanas are unique birds that use their long toes to walk delicately across lotus leaves and catch underwater prey. This episode, filmed between the rainy season and dry season in Kakadu, follows a father bird raising his chicks through their dramatic and difficult first year.
The Cave of Swallows in Mexico is a 400m vertical shaft, deep enough to engulf the Empire State Building. The Lechuguilla cave system in the USA is 193km long and 500m deep with astonishing crystal formations hanging from its chambers. Although often overlooked, caves are remarkable habitats with equally bizarre wildlife. Cave angel fish cling to the walls behind cave waterfalls with microscopic hooks on their flattened fins. Cave swiftlets navigate by echo-location and build nests out of saliva. The Texas cave salamander has neither eyes nor pigment. Unique access to a hidden world of stalactites, stalagmites, snotites and troglodytes brings a wealth of surprises.