Can the market save an endangered species? South Africa’s rhino horn conundrum

Rhinoceros horns are worth more than their weight in gold – literally, about $65,000 per kilo. This is due to strong black-market demand in China and South Asia, where beliefs about the horn’s healing and aphrodisiac properties persist. The species is on the brink of extinction, with a global population under 30,000 and shrinking, while poaching increases in response to growing demand. As of late 2015, the extraordinary creature’s fate rests largely in the hands of the Constitutional Court of South Africa, the country’s highest judicial authority, which is considering a case brought by two rhino breeders, John Hume and Johan Kruger, to overturn the domestic ban on selling rhino horn. Supporters of a legalised horn trade argue that it would encourage investment in rhinos, spurring an increase in the population and more security to protect the valuable property the animals represent. Moreover, they say, the horns can be removed largely painlessly and grow back at a rate of a kilo a year. Critics counter that leaving the rhino’s fate to market forces is irresponsible, unethical and unlikely to succeed. Legalisation, they believe, would create more unsustainable demand, encourage false ideas about the horn’s medicinal value, and set an untenable precedent for conservation of all species based solely on their economic utility.

Nuanced and evenhanded, The Last Rhinos is a thought-provoking exploration of what it means to protect and live alongside wildlife in the 21st century.

Far from sluggish: the remarkable sea creature that weaponises its dinner

Nudibranchs, also commonly known as sea slugs, are a group of snail-like sea invertebrates. Despite appearing more or less defenceless, nudibranchs broadcast their whereabouts with their flamboyant, brightly coloured bodies. From an evolutionary standpoint, it might seem like a curious move, but their luminous skin actually serves as a warning to would-be predators to let them know they’d make for a dangerous meal. While some nudibranchs accumulate toxins and other defensive chemicals in their bodies, others – like the star of this film – have an even craftier method of warding off enemies. This remarkable short from the science and nature documentary series Deep Look details the clever way that some nudibranchs protect themselves by stealing defences from stinging sea animals known as hydroids. You can read more about this video at KQED Science.

‘My God! Where’s the human voice?’ A charming reflection on our pre-recorded world

From to Siri to subways to customer service calls, pre-recorded and robotic voices are becoming an increasingly inescapable part of the human experience. In this short animation from StoryCorps, the US author, historian and broadcaster Studs Terkel (1912–2008) reflects on this trend away from human interaction and toward disembodied sentence fragments. Recalling a scene from a tram ride at Atlanta airport with exceeding wit and charm, he considers the richness of the human voice, and what we lose when it’s replaced.

From canoes to cities, a frenetic celebration of the power of indigenous Canadians

In her short film Mobilize, Caroline Monnet – a Canadian filmmaker and artist of French and Algonquin origin – uses archival documentary footage to honour the restless diligence of Canada’s indigenous people. Given access to more than 700 films from the National Film Board of Canada for the project, Monnet crafts a fervent visual collage that spans the country’s rural north, where indigenous craftsmen are seen fashioning canoes, to scenes from skyscraper construction in the urban south. According to Monnet, in making the film, she sought to explore the trajectory of her own family’s history, as well as to simply bombard viewers with ‘images of indigenous people kicking ass on screen’. Heightened by a feverish score from the Inuk artist Tanya Tagaq, Monnet’s film offers a deeply original and personal perspective on the indigenous Canadian experience.

This clever and stylish 1960 film is the most fun you’ll ever have at a physics lecture

Directed by the pioneering UK documentarian Richard Leacock, Frames of Reference is a slick and surreal dive into physics fundamentals and, in particular, why everything is indeed relative. Produced for high-school physics classes, the 1960 film features the physics professors Patterson Hume and Donald Ivey of the University of Toronto explaining, through an intertwined series of lectures and clever demonstrations, how frames of reference shape perspective. Using rotating sets, camera tricks and a visual style that suggests the film noir of Alfred Hitchcock, this is perhaps the most peculiarly entertaining half-hour physics lecture you’ll ever have.