What wrapping a rope around the Earth reveals about the limits of human intuition

If you tied a rope tight around the Earth’s equator and then added a single yard of slack, would the extra material make any noticeable difference to someone standing on the ground? Yes, actually. The answer comes as a surprise to most people, but the additional bit of rope raises it high enough off the ground for our eyes to easily discern it, and our feet to easily trip over. That fact might seem trivial, but the early 20th-century philosopher Ludwig Wittgenstein believed that this chasm between human intuition and physical reality revealed something important about the fallibility of our thinking. After all, if something that seems obvious to almost everyone can be totally false, what else might we be wrong about? This video from the Center for Public Philosophy at the University of California, Santa Cruz breaks down the mathematics behind Wittgenstein’s knotty example, and asks whether it should make us all feel a bit less certain about even our most deeply held beliefs.

Time dilates and people flow in and out of each other in a hallucinatory urban commute

Warning: this film features rapidly flashing images that can be distressing to photosensitive viewers.

A commute is often judged good or bad by how long it takes, but sometimes getting from one place to another can yield wrinkles in our experience of time. The Japanese filmmaker Hiroshi Kondo explores this phenomenon in his often breathtaking video Multiverse, layering time on itself to create a hallucinatory vision of countless scooterists flowing through Taiwan’s capital Taipei. The result is a vision of a city and its people that takes an ordered freneticism and manipulates it to create a sense of time speeding up and standing still. People are momentarily discernible as individuals before morphing into strange amalgams of humanity. As the piece progresses, the pace becomes increasingly dizzying, until finally the crowd melds into an amorphous blur of light and motion. For another surreal take on the urban world from Kondo, watch his video Eye Know (2014).

Flight manifest: from take-off to landing, a bird’s eye introduction to flying

It seems to be a deeply human experience to catch sight of a bird on the wing and stand there entranced, whether by a hummingbird’s frenetic zipping lines, a hawk’s graceful curves or any of the countless other forms of avian flight. Created by the US animator Stephen Cunnane as a tool to demonstrate realistic bird movements to other animators, this breezy short renders winged flights using silhouettes, detailing the key manoeuvres of avian aerodynamics. If only this how-to manual allowed us to take to the air ourselves… For more from Cunnane, watch his companion animation Animal Gaits.

A horse walks into a pub: on the excruciating trauma of being told a joke

You’re at a party, perhaps finding your next drink, when someone you hardly know comes up and asks: ‘Hey, want to hear a good one?’ The real answer is almost always: ‘No, thank you,’ but as a polite guest, what choice do you really have? This excerpt from the film Shepherd’s Delight (1984) drops the viewer directly into this awkward scenario, with a quip about two racehorses talking shop in a bar. As the joke-teller eagerly addresses his audience, a wry running commentary breaks down the psychological minutiae of joke-telling, including the many emotions – from discomfort to sweet relief – experienced by the audience. Infused with a peculiar, subversive sense of humour, the UK filmmaker John Smith’s short is a mad meta-comedy – clever, a bit mean and discomfitingly relatable.

Don’t misread Darwin: for humans, ‘survival of the fittest’ means being sympathetic

One of the shockwaves from Charles Darwin’s idea that humans evolved from other animals was moral panic. If our ethics are not guided by an omnipotent and all-knowing god and, instead, life is driven by ‘survival of the fittest’ via natural selection, how could we possibly expect humans to behave with anything other than brash self-interest? Yet Darwin’s use of the phrase ‘survival of the fittest’ was hardly meant to suggest that existence was a knockdown, drag-out fight – he was very clear that generosity, sympathy and all those other traits that give us warm feelings are central to human survival. In this short video, the psychologist Dacher Keltner at the University of California, Berkeley puts kindness in evolutionary context, connecting his own recent neural-imaging work on compassion with Darwin’s view that sympathy is a cornerstone of human flourishing.