Logic tells us that antimatter should have annihilated the Universe. So why hasn’t it?

In 1928, the UK physicist Paul Dirac stumbled on an equation that seemed to show that, for every particle, there’s another, nearly identical particle with an opposite electric charge. Just four years later, the US physicist Carl David Anderson proved Dirac’s prediction correct by capturing a picture of a ‘positron’ – a particle with the same size and mass as an electron, but with a positive charge rather than a negative one. This rapid series of developments unlocked one of the most momentous and enduring conundrums of physics: if particles with opposite electric charges annihilate one another when they meet, why is there any matter left? And if there’s no more matter than antimatter in existence, then the Universe should have annihilated itself soon after the Big Bang – yet, here we are. This brief animation breaks down this extraordinary, nearly century-long science puzzle, detailing some of the surprising explanations posited by contemporary physicists.

A street-level view of homelessness from a woman living through it

Many portraits of homelessness still end up ‘othering’ people, despite their storytellers’ best intentions. The UK-based Italian filmmaker Giulia Gandini wanted to try something different, aiming to capture an account of homelessness without imposing her own biases. Lily Blackham had been living on London’s streets for 18 months after escaping an abusive relationship when Gandini gave her an iPhone to chronicle her experiences over three days and tell her own story. The resulting short film, Home Stream, is a touching first-person glimpse into the many practical and emotional complications of homelessness and rough sleeping – from feeling invisible to passersby to not having money for sanitary pads. In doing so, Gandini and Blackham build a deeply humanising portrait of a life on the margins, replete with heartache and struggle, but not without moments of joy.

Via Directors Notes

A curtain that twitches as people walk by creates a delightful paradox of privacy

In 2010, the German artist Niklas Roy embarked on a project to take back a small slice of privacy in an era and in a place – his Berlin workshop – where it can be quite hard to come by. The resulting installation, My Little Piece of Privacy, comprised a surveillance camera, ‘computer vision’ software and a small, motorised curtain, which followed pedestrians as they walked past his storefront. As you might imagine, the moving curtain had an inverse (and amusing) effect, causing passersby to spend far more time in front of his window than they would have otherwise. This short video, featuring scenes from the installation set to a retro arcade-inspired score, makes a highly entertaining spectacle out of Roy’s clever provocation of privacy.

Via Colossal

Climate change science is centuries, not decades old, and it was pioneered by a woman

The notion that human activities might be warming the planet started coming into focus in the 1960s and ’70s, before a scientific consensus emerged in the 1980s and ’90s. But the rough outlines of the science surrounding humanity’s greatest contemporary threat has a surprising, little-known history that dates back roughly two centuries. This brief animation from BBC Ideas traces our modern understanding of the greenhouse effect through the work of three pioneering scientists, beginning with the US scientist and women’s rights activist Eunice Foote, whose 1856 work on the heat-trapping effects of CO₂ was buried for decades before being rediscovered in 2010.

After 30 years of solitude, Peter forms an unlikely friendship with a fellow loner

‘I had left my flock, and Ben had left his.’

After taking a walk through a remote Welsh valley, Peter committed himself to a life there, and disconnected from the outside world. In doing so, he found a solitary inner peace – a peace he maintained for nearly three decades, until, one day, he stumbled upon a lamb that had been left for dead. Finding kinship with the fellow ‘dropout’, Peter took the abandoned creature home and named him Ben. The short Peter and Ben (2007) by the UK filmmaker Pinny Grylls captures the duo’s relationship three years after their chance meeting, as Peter attempts to return Ben to the wild. With a melancholic piano score and sweeping views of the Welsh countryside, her touching film lends a lyrical beauty to this tale of unlikely connection and camaraderie between outsiders.