illusion

Neuroscientist Beau Lotto runs the audience through color and pattern illusions to show that perception is shaped by context and evolutionary history rather than being a direct readout of the world. The talk is playful and hands-on, and it argues that the brain interprets ambiguous signals.

A PBS Space Time episode hosted by Gabe Perez-Giz on the nature of spacetime and whether space and time are fundamental. It builds up reference frames and causality in a short, dense format.

A five-minute demonstration of the Shepard tone, an audio illusion made from octave-separated tones that makes pitch seem to rise endlessly without ever getting higher.

Captain Disillusion debunks the Cicret Bracelet, a crowdfunded wearable that claimed to project a touchscreen onto the wrist. He looks at the concept, design, execution and fundraising.

Captain Disillusion debunks a viral Chinese invisibility cloak video while parodying popular educational channels. Along the way he explains chroma keying and green screen techniques.

Captain Disillusion's comedic, fast-paced explainer on how color works in cameras, displays and video. It covers the biology of color perception and what it means for screens.

Numberphile visits Cliff Stoll, the man behind ACME Klein Bottles, and sees how he stores a thousand glass Klein bottles in a crawlspace under his house. A remote-controlled forklift fetches them.

Kurzgesagt animates Andy Weir's short story The Egg, in which a person learns that they are every human who has ever lived. It adds music and narration to the original text.

CGP Grey explains split-brain patients, where severing the corpus callosum lets the two hemispheres act independently. He uses this to explore the idea of two minds in one head.

A ten-minute card-magic act by Dani DaOrtiz performed on Penn & Teller: Fool Us in 2022. It is built on timing, misdirection and psychology, and the method defeated the show's hosts.

An excerpt from the 1983 BBC series Fun to Imagine in which Richard Feynman describes how he and a mathematician friend counted in their heads in different ways, one verbally and one visually. It shows that people can reach the same goal through quite different mental methods.

Archer Lars Andersen demonstrates fast, accurate shooting techniques he says he revived from historical art and texts, arguing Hollywood archery is not historical.

A binaural audio demo, the 'Virtual Barber Shop', that places a barber moving around your head. It works best with headphones and closed eyes.

The Lock Picking Lawyer tests the supposedly unpickable lock designs built by the Stuff Made Here channel. He looks for bypasses and weaknesses in the novel anti-picking mechanisms.

A short edited excerpt of Terence McKenna arguing that culture acts as an operating system for the mind, set to imagery and music. It touches on psychedelics and how they change thinking.

Moral philosopher James Flynn explains the Flynn effect, the steady rise of IQ scores across the 20th century. He argues the shift reflects a move toward abstract, hypothetical thinking as cognitively demanding professions grew.

Magician Kostya Kimlat performs a card trick on Penn & Teller: Fool Us that fooled the duo, using Penn's favorite card trick as a basis.

An RSA Animate summary of Iain McGilchrist's lecture on the divided brain, arguing the brain's two hemispheres attend to the world differently and that this has shaped culture and society.

A clip of psychologist Jordan Peterson lecturing on intelligence and IQ, covering how it is defined and its correlation with academic and work success.

Neuroscientist Karl Friston gives a 15-minute talk on the free energy principle, covering Markov blankets, Bayesian model evidence and global brain theories.

An artist describes discovering she has aphantasia, the inability to form mental images, and how it affects her work. She asks viewers about their own visualization.

Bloomberg Technology interviews Google engineer Blake Lemoine about the experiments that led him to believe LaMDA was sentient and why he was placed on administrative leave. He also raises concerns about AI ethics at Google.

Hungarian folk dancers from Sapientia University act out the quicksort algorithm step by step, with music. It is part of the AlgoRythmics series of sorting algorithms performed as dance.

Brian Douglas introduces Braitenberg vehicles, simple robots whose sensors are wired directly to motors yet show surprisingly lifelike behavior. He draws on Valentino Braitenberg's book Vehicles.

Wintergatan's video of the Marble Machine, a hand-built music instrument that plays a song using about 2000 marbles on a mechanical clockwork-style mechanism.

Vsauce explores math through card tricks and big numbers, including an animation of how enormous 52 factorial, the number of deck orderings, really is.

A recorded phone call in which the Lenny bot, a looping set of prerecorded replies from a rambling old man, keeps a telemarketer on the line for 14 minutes. The uploader calls it the best Lenny call yet.

Vsauce explores qualia and whether different people experience colors the same way. It draws on color blindness, Mary's room, the explanatory gap and subjective experience.

Neuroscientist Anil Seth argues in this TED talk that perception is a controlled hallucination: the brain constantly predicts the world and our shared agreement is what we call reality. He also touches on the construction of the self.

CGP Grey asks whether Star Trek-style teleportation would kill you and recreate a copy, working through the philosophy of identity and the Ship of Theseus. It is a short animated explainer.

PBS Space Time examines Roger Penrose's idea that consciousness arises from quantum processes in the brain, and reviews new evidence about microtubules. It ends with an estimate of what replicating consciousness would demand.

A student interviews Kirsten Carlson, who does not have an internal monologue, and she answers questions about how she thinks. The video grew out of a viral article about people lacking inner speech.

Tom Scott, with linguists Gretchen McCulloch and Molly Ruhl, examines whether the language you speak changes how you think. The short answer is mostly no, with caveats about the weak version of the Sapir-Whorf hypothesis.

A short video of a man moving a 20 ton stone block by himself using wood and levers. It is part of a pyramid-mysteries channel.

Theo Jansen shows many of his Strandbeests, wind-powered walking kinetic sculptures, set to Khachaturian's Spartacus. It presents his work since 1990 on creating new forms of life on beaches.

An excerpt of Richard Feynman's 1985 lecture Q&A about whether machines can think. He discusses the difficulty of defining what computers can never do and compares machine intelligence to machines that don't copy animals.

Mentalist Derren Brown plays nine skilled English chess players, including four grandmasters, simultaneously on his TV show. The trick behind the apparent win is the point of the segment.

Penn and Teller help Rob Pike and Dennis Ritchie of Bell Labs play a prank on Nobel-winning physicist Arno Penzias. The clip shows the gag and its setup.

Mike Boyd takes up Smarter Every Day's challenge to learn to ride the Backwards Brain Bike, a bicycle whose steering is inverted, and rides 50 meters. It shows how hard it is to unlearn a motor skill.

Captain Disillusion explains the visual effects behind the Back to the Future trilogy. He covers ILM's motion-control, computer-controlled camera work and clever pre-CGI tricks.