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.

After losing his sight, a skateboarder takes an unexpected path to realising his dreams

Nick Mullins fell in love with skateboarding as a teenager and, rather quickly, became quite skilled. As one of the best young skateboarders in the Detroit area, he was putting together a video to catch the attention of sponsors, when, after taking a rough but mostly innocuous fall, he scraped the side of his body and contracted a staph infection. He would barely escape with his life, and after waking up from a medically induced coma, realised he had gone blind. Believing he had no prospects – in skating or in life – he fell into a deep depression. The short documentary You and the Thing That You Love retells how Mullins would eventually realise his dreams, albeit by taking a very much unanticipated path. Capturing Mullins’s story with kinetic style, the US filmmaker Nicholas Maher avoids cliché to create a standout portrait of perseverance and love of craft – and one that can be savoured even if you don’t know your ‘blunts’ from your ‘fakies’.

Algorithms are sensitive. People are specific. We should exploit their respective strengths

The capabilities of algorithms and human brainpower overlap, intersect and contrast in a multitude of ways, argues Hannah Fry, an associate professor in the mathematics of cities at University College London, in this lecture at the Royal Institution from 2018. And, says Fry, planning for an efficient, ethical future demands that we carefully consider the respective strengths of each without stereotyping either as inherently good or bad, while always keeping their real-world consequences in mind. Borrowing from her book Hello World: Being Human in the Age of Algorithms (2018), Fry’s presentation synthesises fascinating studies, entertaining anecdotes and her own personal experiences to build a compelling argument for how we ought to think about algorithms if we’d like them to amplify – and not erode – our humanity.

New York’s 300-year-old trash becomes treasure in the hands of an urban archaeologist

Scott Jordan’s two-bedroom apartment in Queens, New York is filled with thousands of local artefacts, many of which date back centuries. Populating his shelves and drawers are glass bottles, porcelain dolls, pottery and even a gun from the Revolutionary War – all of them once buried far beneath New Yorkers’ feet, and many of which he’s repurposed to create original art. This small museum of recovered treasures comes from years of playing in the dirt and digging out landfills, cisterns and privies by hand. In The Artefact Artist, the US director Russ Kendall explores the buried history of cities, and how Jordan finds meaning and community in the process of searching for, discovering, and transforming objects others have left for trash.

A former Guantánamo Bay prisoner and his guard reunite as equals 13 years later

Born in Mauritania in northwest Africa, Mohamedou Ould Salahi was living in Germany on a college scholarship when he travelled to Afghanistan to support Al-Qaeda’s US-backed fight to topple the country’s Soviet-supported government in 1990. Although he says he extinguished all ties with the militant Islamist group in 1992, and was never formally charged with a crime, accusations of Al-Qaeda links trailed him until, in the wake of the terrorist attacks on the US of 11 September 2001, he was detained from Mauritania by the US government. Salahi was ultimately transported to the Guantánamo Bay detention camp in Cuba, where he was repeatedly tortured, before being released back to Mauritania in 2016. While jailed, he became an unlikely international bestselling author after the publication of his memoir, Guantánamo Diary (2015). Salahi’s book was subsequently adapted into the feature film The Mauritanian (2021).

The short documentary My Brother’s Keeper from the UK filmmaker Laurence Topham captures Salahi’s post-release life in Nouakchott, Mauritania, a country he’s now not allowed to leave, and where he’s attempting to adjust to something resembling normality. In particular, the film focuses on Salahi’s reunion with Steve Wood – a Guantánamo guard who showed him kindness, friendship and the many pleasures of the Coen brothers’ film The Big Lebowski (1998) while Salahi was imprisoned. The visit marks their first meeting in 13 years, as well as their first since Wood, inspired in part by Salahi, converted to Islam. Boosted by Salahi’s infectious charm, the film provides a moving testament to the power and durability of human connection, even in the unlikeliest of places.