How our developing understanding of plants changed our knowledge of life itself

With some 7 million dried plant specimens, the herbarium at Kew Gardens in London is one of the largest collections of its kind in the world. Building on the Linnaean system, through Darwin to DNA, scientists there have traced the relationship between plant life-forms and the timeline of their development over the ages – from algae to mosses to flowers. While the plant family tree is thought to be 95 per cent complete, this short documentary reveals that continuing to study plants gives us an important framework for asking questions about how our ecosystems actually work.

Learn to build your own rainproof hut – or, at least, marvel at the man who knows how

The popular Primitive Technology YouTube channel features an anonymous man in Far North Queensland in Australia fashioning tools and structures using only naturally occurring, found materials. In this installment, following the deterioration of his A-frame hut, he builds what he hopes will be a more durable round hut from the ground up. Starting with wood posts tied together with cane, the man makes the structure water-resistant by adding a palm roof, a drainage trench, and walls built from a combination of mud and cane. In the process, he also almost manages to make his remarkable ingenuity look easy. To learn more about the step-by-step process while watching, turn on closed captions in the video player. 

‘I thought I was gonna be a teenager forever’: moving back in with the parents at 23

In his short documentary Baby Brother, the US filmmaker Kamau Bilal offers a bit of vérité filmmaking at its most refreshing, transforming the mundanity of his younger brother’s return to their parents’ Missouri home into a funny and poignant exploration of the weirdness of young adulthood. Ismaeel is 23 and affable, if somewhat hapless, but the intimacy of his brother’s filmmaking – and presumably his affection for Ismaeel – makes the treatment of the young man’s charms, flaws and idiosyncrasies gently revelatory. His stifled ambitions and uneasiness about the trappings and responsibilities of adulthood echo a distinctly millennial malaise, at the same time as being deeply rooted in his personal experience. This heartfelt and charming short was a favourite on the 2018 film festival circuit, screening at the Sundance Film Festival, True/False and Sheffield Doc/Fest, among many others. 

Scientists haven’t tamed volcanoes but it’s wild and fun to watch them try

During a fellowship at the Mineral Sciences Laboratory at the Smithsonian National Museum of Natural History in Washington, DC, the UK filmmakers Ruth Jarman and Joe Gerhardt stumbled upon a collection of 16mm films shot by volcanologists in the field. Originally presented as an installation at the Foundation for Art and Creative Technology (FACT) in Liverpool in 2011, this three-channel video combines the found footage with a churning, propulsive soundtrack to explore the human fascination with Earth-rupturing natural phenomena. Across the three channels, erupting volcanoes are at once powerful forces of nature as well as fodder for quantifiable scientific data – and high jinks.

A veteran returns to war through virtual reality, hoping to be rid of his PTSD

Almost 40 years after post-traumatic stress disorder (PTSD) was officially recognised as a distinct mental condition, treating its frequently debilitating symptoms has proven extremely challenging to sufferers and clinicians. The human brain is hard-wired to defend against threats, making little distinction between real and perceived danger. However, Merel Kindt, a professor of clinical psychology at the University of Amsterdam, believes that she has discovered a breakthrough treatment for overactive fear responses. By first exposing patients to their greatest fears and then administering a beta-blocker called propranolol, Kindt says that fear memories can be overwritten and made benign. 

This is the second instalment of the US director Lana Wilson’s four-part documentary series A Cure for Fear, which follows patients undergoing this potentially revolutionary treatment. It features Kindt attempting to alleviate the PTSD symptoms of a Canadian veteran of the war in Afghanistan: to trigger the fear memory, he must relive his most traumatic battle experience in harrowing detail via an immersive VR recreation. Watch the first instalment of the series here.