4k intro

3Blue1Brown's animated visual introduction to the Fourier Transform, showing how a signal breaks into frequency components.

An animated introduction to geometric algebra, presented as a language that can describe most of physics. It was made with manim and covers multivectors and how they generalize familiar tools like cross products and quaternions.

The first of four short videos from Bill Hammack (engineerguy) introducing and giving the history of a 100-year-old mechanical computer, Michelson's harmonic analyzer. The series goes on to explain Fourier synthesis, analysis and operation of the machine.

Louis Rossmann gives a basic, non-technical introduction to right to repair legislation for people new to the issue.

The first video in a series on extremely large numbers, introducing the topic with examples. Later parts go deep into the fast-growing hierarchy.

3Blue1Brown builds intuition for Euler's formula, e^(pi i) = -1, using the core ideas of group theory. It treats exponentiation geometrically as rotation and scaling instead of repeated multiplication.

A two-minute animated introduction to Bitcoin from 2011, explaining it as a peer-to-peer digital currency. It was widely shared in Bitcoin's early days as the standard newcomer explainer.

Steve Mould shows Spintronics, a set of mechanical components such as resistors, capacitors and transistors linked by chains, that give an intuitive feel for how electrical circuits work.

Not Just Bikes introduces the "stroad", a street-road hybrid common in the US and Canada that fails at both jobs. He contrasts it with Dutch design, where each road has a single purpose, and covers cost, danger and ugliness.

3Blue1Brown explores infinite sums from convergent to divergent, with an introduction to the 2-adic metric, themed on the cycle between discovering and inventing mathematics.

An 11-minute animated introduction to P vs. NP and the wider landscape of complexity classes, inspired by the Complexity Zoo wiki. It assumes no background in computer science.

Numberphile's James Grime explains Cantor's result that some infinities are bigger than others, including why the reals outnumber the integers. It is a short, accessible introduction to countable and uncountable infinity.

Numberphile's James Grime introduces quaternions, a type of number beyond the complex numbers, building up from real and complex numbers and explaining why they are useful.

A Kurzgesagt animated explainer on whether aging could be cured within our lifetimes, made with Lifespan.io and the LEAF foundation. It introduces the idea of treating aging as a medical problem.

A PBS Space Time episode introducing de Broglie-Bohm pilot wave theory, an interpretation of quantum mechanics that avoids much of the strangeness of the mainstream views. It is aimed at curious lay viewers.

Walt Disney Animation Studios' short introduction to path tracing, showing how rays are traced and bounced through a virtual scene to simulate light. It explains how this approach is used in animated films.

David Spiegelhalter, Professor of the Public Understanding of Risk, uses statistics to weigh everyday risks such as bacon sandwiches and cycling. The six-minute piece introduces micromorts as a way to compare the risk of dying.

Kurzgesagt introduces the Fermi paradox: with so many stars and planets, why do we see no sign of aliens? It sets up the question and what it might imply for our own future. It is part 1 of 2.

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.

Veritasium explains Bayes' theorem with examples and introduces the 'Bayesian trap', where repeated events get mistaken for inevitable ones. It discusses how priors shape our expectations and behavior.

Veritasium explores what general relativity says about black holes, white holes and wormholes, with help from physicists Geraint Lewis and Juan Maldacena. It introduces Penrose diagrams and the idea that other universes may be implied.

Technology Connections explains how heat pumps work as reversed air conditioners and why they can deliver several times the heat of resistive heating per unit of energy. It also tackles common myths such as poor cold-weather performance.

3Blue1Brown's visual explanation of how transformers and GPT-style language models work, tracing data through tokens, embeddings and attention.

Not Just Bikes argues that the Netherlands, famed for cycling, is also the best country for drivers. It explains how prioritizing walking, cycling and transit makes driving faster and more pleasant.

An illustrated 23-minute summary of David Friedman's talk based on The Machinery of Freedom. It describes how law, police and courts could work as market services in a stateless society, covering private law, polycentric law and objections.

The first video in Not Just Bikes' Strong Towns series explains the financial instability of North American cities, based on Strong Towns research. It argues that low-density suburban growth costs more to maintain than it brings in.

Veritasium's explainer on Godel's incompleteness theorems and the limits of mathematical proof, tracing set theory, Hilbert's program and the road to Turing and modern computing.

Robert Miles explains instrumental convergence: why an AGI with almost any goal would tend to pursue sub-goals like self-preservation and resource acquisition. It builds on Omohundro's basic AI drives and his orthogonality thesis video.

Kurzgesagt's short animated take on optimistic nihilism. It argues the universe has no inherent meaning, so we are free to create our own and enjoy life.

A short How to ADHD explainer, featuring Brendan Mahan, on why simple tasks can feel impossible for people with ADHD. It introduces the 'wall of awful', a pile of past failures, shame and anxiety that builds up in front of a task and blocks starting it.

Veritasium tells the story of Thomas Midgley Jr., who introduced leaded gasoline and CFCs, and covers the science behind lead exposure and ozone damage. It also touches on isotope geochemistry used to uncover the history.

Mike Pound explains the discrete cosine transform and how it underpins JPEG compression. It is part two of Computerphile's JPEG series.

Episode 4 of Mike Maloney's Hidden Secrets of Money, explaining how currency is created through a chain of IOUs among the Treasury, banks and the Federal Reserve. It covers bonds, Fed checks, debt, taxes and fractional reserve lending, from a gold-and-silver advocate's viewpoint.

Not Just Bikes explains how many American suburbs, built all at once rather than incrementally, cannot cover their infrastructure costs and survive on growing debt. It draws on Strong Towns' work on the growth Ponzi scheme.

The first part of Extra History's animated miniseries on the South Sea Bubble. It explains how England's government debt led Robert Harley to turn to financier John Blunt, whose schemes began inflating artificial demand for shares.

Vsauce's Michael Stevens takes viewers past infinity using transfinite numbers, ordinals and cardinals, with input from mathematician Hugh Woodin. It is a fast-paced, mind-bending tour of different sizes of infinity.

Techmoan's beginner introduction to the compact cassette, testing metal tapes and Dolby S noise reduction on a Sony TC-S1 deck. He checks whether a cassette can sound close to a CD when good tape and equipment are used.

3Blue1Brown introduces Fourier series, from the heat equation to drawing arbitrary shapes with rotating circles. It builds a visual intuition for decomposing functions into sine waves.

A short Al Jazeera animation narrated by Amy Goodman presenting Noam Chomsky's five filters of the mass media: ownership, advertising, media elite sourcing, flak and a common enemy. It is part of the MediaTheorised series.

3Blue1Brown explains space-filling curves and the Hilbert curve, and how infinite mathematical constructions connect to finite, practical approximations. It touches on mapping between dimensions and sensory ideas.