The mathematics of music means piano strings can never be in perfect harmony

Unlike with guitars and violins, pianos’ strings can never be perfectly tuned to one another. The solution? As this short animation from MinutePhysics explains, the instrument’s 88 strings across more than seven octaves means tuning a piano using harmonic intervals will inevitably lead to notes being fractionally off-pitch, with the issue compounding across octaves. So instead of using harmonics, piano-tuners generally keep octaves perfect, while leaving every other interval out of tune by just a tiny fraction. This workaround forsakes the appealing mathematical patterns of harmonics, but makes it possible to keep the kind of uniformity that is so valued in an era of mass production and reproduction of music.

Where Soviet cars go to not quite die – driving adventures in northern Russia

The Lada is a stalwart symbol of Soviet Russia. It has also been considered one of the worst cars ever made. Its heyday, if it had one, was in the 1970s, but a substantial number of vehicles remain on the roads today, and hold a special place in the hearts and minds of many Russians. To tell the story of this much-ridiculed car, the filmmaker Dieter Deswarte, the cinematographer Annegret Sachse and the sound engineer Yulia Glukhova travelled the Russian north, from Murmansk to Siberia, to find where the cheap and easily repairable – if reliably unreliable – vehicles are still in action. Along the way, they got to know a colourful range of drivers who recount the complexities of Lada ownership, and, more important still, show the car on the road – or sometimes what it takes to get it on the road. Undercutting broad Western stereotypes of a certain Russian dourness, the filmmakers find humour, warmth and kindness in their driving adventures across the icy landscape.

Lada debuted in 2014 as part of the award-winning omnibus documentary Cinetrain: Russian Winter. An ambitious and inventive filmmaking initiative, the Cinetrain project sent 21 filmmakers from around the world to all corners of Russia to explore its culture through the spectrum of stereotypes – from mail-order brides to heavy drinking. The project was inspired by the work of the influential Soviet Russian filmmaker Aleksandr Medvedkin (1900-89) who, in 1934, built a mobile film studio inside a train before setting out to document life across the country.

The Bing Bang, reincarnation and other theories of life from budding philosophers

What’s the point of life? Kindness? Recycling? Leaving your body to science? This hybrid of animation and live-action from 2009 generates good fun and plenty of food for thought from its simple premise: asking children some of the most enduring questions in philosophy. While many of the answers – including an innovative ‘exploding monkey theory’ of Homo sapiens origins –  are simply great material for the accompanying animations, others brush up against the current limits of human understanding, prompting meaningful reflection on how we think about life. With its abundance of laugh-out-loud and heartfelt moments, the Montreal-based director Karina Garcia Casanova’s playful film is a worthy tribute to the deeply creative thinking of kids.

A Nobel laureate and a flea circus join forces for an unforgettable demonstration of inertia

The Physical Science Study Committee (PSSC) was formed in 1956 at the Massachusetts Institute of Technology with the mission to create science-education materials for US high-school classrooms. Extracted from a PSSC film from 1959, the first half of this short video finds the Nobel Prize-winning physicist E M Purcell from Harvard University detailing the basics of inertia with some help from a frictionless dry-ice puck – which, by his exceptionally impassive account, is a thing that’s ‘fun to play with’. The video gets a good deal stranger in the second half, which takes viewers on a field trip to Hubert’s Museum in New York City: a long-since defunct cabinet of 10-cent curiosities that was once a Times Square mainstay. There, Hubert’s famed in-house flea circus puts its considerable talents on display as the ringmaster leads a one-of-a-kind inertia demonstration. It all makes for an impressive proof of concept, and some delightfully dated fun.

When your parents survived Auschwitz, where do you fit into the family story?

‘You see, I have this problem: growing up in my parent’s house was not tragic. But their past was.’

Coming of age in Toronto during the 1960s, the Canadian writer and illustrator Bernice Eisenstein found herself ‘addicted’ to the Holocaust, consuming every film and book on the subject that she could. The tragedy largely defined the lives of her parents, Auschwitz internees who were moulded by both the enormity of their grief and the friendships they forged with fellow survivors. But to Eisenstein, who grew up in relative comfort, the Holocaust was at once omnipresent and alien – lore from a recent past she would never touch and could never fully understand, but one that informed her identity in inescapable ways. The animated film I Was a Child of Holocaust Survivors (2010) adapts Eisenstein’s celebrated 2006 graphic memoir of the same name. Borrowing her distinctive visual style and wit, the short explores Eisenstein’s personal history with honesty and a bit of poignant humour to probe questions of secondhand trauma and the sometimes unbridgeable chasms between generations.