The plodding photon, or how the speed of light looks sluggish on a galactic scale

According to Albert Einstein’s theory of special relativity, the speed of light (approximately 299,792 kilometres – or roughly 7.5 rotations around the Earth – per second in a vacuum) is the Universe’s speed limit, and therefore the fastest we could ever hope to travel through space. Swift as it might seem, when it comes to traversing the vast expanses between solar systems and galaxies, it’s still very slow-going. Indeed, the nearest galaxy to the Milky Way, Canis Major, is 25,000 light years away. Set to a mesmerising score by the US composer Steve Reich, Riding Light is an illuminating look at light speed, simulating the journey of a photon from the Sun’s surface to just beyond Jupiter’s orbit. For a brisker take, see a condensed, three-minute version of the same video here.

A millimetre makes a world of difference when calculating planetary trajectories

Calculating the trajectories of two gravitating bodies is straightforward mathematics. But introducing even just one more variable into an orbital system can make its long-term trajectory impossible to predict. In 2009, two researchers at the University of California, Santa Cruz investigated just how difficult this mathematical phenomenon – known as the ‘N-body problem’ – makes forecasting the eventual fate of our own corner of space. The team ran 2,000 simulations of the solar system’s trajectory up to 5 billion years into the future, with the only variable being less than a millimetre difference in the distance between Mercury and the Sun. The simulations yielded a stunning array of results, including the possibility of Mercury careening into the Sun, colliding with Venus and destablising the entire inner solar system. This animation from TED-Ed breaks down the N-body problem with rich visuals and methodical clarity, and concludes with scientists’ efforts to minimise N-body unpredictability as humans press further into space.

Eight men reflect on their paths to prison – and imagine their alternative lives

An idiosyncratic patchwork of reflection, fantasy and atonement, the German director Adrian Figueroa’s experimental documentary Elsewhere invites viewers to step inside the minds of eight men serving extended terms in a German prison. As each inmate talks about the path that led him to incarceration, their distinct life stories, personalities and talents emerge, with the only clear connection between them being their shared quarters. While discussing topics ranging from the unparalleled highs of performing a robbery to the clarifying power of meditation, the men are green-screened into escapist settings aligned with their imaginary selves, and far removed from the drudgery of their locked-away lives. The result is at once enlightening and disorienting – and quite unlike any other ‘behind prison walls’ documentary you’re ever likely to see.

Elsewhere was awarded online distribution by Aeon Video at the 2020 Cheap Cuts Documentary Film Festival.

The uncanny allure of the annual Cajun crawfish festival in Louisiana

Crawfish – small crustaceans also known as crayfish, crawdads or mudbugs – have long been a staple of Cajun cuisine, with the lobster-like creatures plentiful in the freshwaters of Louisiana. With an observational style and an experimental flair, Acadiana gathers scenes from a day at the state’s annual crawfish festival in Breaux Bridge. A crawfish eating competition, crawfish-inspired costumes and a float procession featuring the 2019 crowned Crawfish King and Queen are captured with a mix of anthropological curiosity and familial respect by the Québécois filmmakers Guillaume Fournier, Samuel Matteau and Yannick Nolin. While its title references the French-Canadian roots of Cajun culture in the United States, there is something otherworldly about this short film, which went on to win several awards on the Canadian film-festival circuit.

‘I hate giving you bad news’: when a daughter with breast cancer calls her mother

Danielle Hernandez is 30 and has Stage 4 breast cancer. As she calls her mother Violeta in Florida to deliver an update on her treatment from her home in Los Angeles, she oscillates between medical jargon and silver livings, with the more difficult pieces of information hidden in the subtext, only occasionally bubbling to the surface. This intimate conversation is captured by her roommate, the US filmmaker Lizzy Hogenson, in the short film Dani. Using a stop-motion technique that combines felt figures and claymation, Hogenson places her own veneer on the discussion, which is pierced by intermittent cracks of raw emotion, hard truths and silence. The result is at once affecting and distressing, as small moments of love, courage and pain spark and fade into uncertainty.