pr

3Blue1Brown walks through a very hard Putnam competition problem and its elegant solution, emphasizing the visual intuition and the thought process behind solving it.

3Blue1Brown's third deep learning chapter gives a visual, intuitive account of backpropagation and what happens to a neural network as it learns. A follow-up video covers the underlying calculus.

Zack Freedman gives advice on why makers fail to finish projects, including scrapping bad ideas, showing work publicly and writing a plan that keeps projects fun. It is aimed at hardware DIY but generalizes.

Kurzgesagt's animated explainer on CRISPR gene editing, covering how the technology works and what it could mean for curing disease, designer babies and aging. It frames genetic engineering as an irreversible change coming to humanity.

Real Engineering explains the materials science behind metal 3D printing, including crystal structure, laser sintering, and why printed parts develop fatigue cracks. It shows how process imperfections limit the strength of printed metal.

A Computerphile video in which Mark Jago of the University of Nottingham explains Turing's halting problem and how it led to the blueprint for the modern computer.

minutephysics, in collaboration with the US Census Bureau, explains differential privacy and why the 2020 census adds noise to protect individuals' data. It walks through how statistics can leak private information.

3Blue1Brown's chapter 4 on deep learning gives a more formal, symbol-based account of backpropagation calculus, connecting the intuition from the previous chapter to the math found in textbooks and code.

3Blue1Brown shows how the uncertainty principle arises from Fourier transforms. A wave packet cannot be narrow in both position and frequency, so the principle is a property of waves rather than of measurement.

David and Ben Crystal introduce the Original Pronunciation production of Shakespeare and show what it reveals about the history of English, including puns and rhymes lost in modern speech.

Numberphile with Daniel Erman on the Josephus problem, where people in a circle are eliminated in turn. It shows how the survivor's position follows a neat pattern tied to powers of two and binary.

A Vox explainer on why California's high-speed rail project is years late and far over budget, with only a few concrete structures built by 2022. It covers the political, legal and routing challenges behind the delays.

Destin of Smarter Every Day goes behind the scenes at the 23andMe lab to show how genotyping works. He also discusses DNA testing and privacy.

A Veritasium video touring Relativity Space and explaining why 3D printing whole rockets cuts tooling costs, allows rapid iteration, reduces part count and enables new designs. It includes an interview with Scott Manley on aerospace engineering.

A short video on the US Sprint anti-ballistic missile, which accelerated to around Mach 10 in seconds under extreme g-forces and heat. It includes striking launch footage and a brief development history.

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.

The Map Men explain why British place names are so hard to pronounce, tracing it to layers of Viking, Anglo-Saxon, Celtic and Norman influence, with a pronunciation guide.

Breaking Taps explains how the cryogenic mirror actuators on the James Webb Space Telescope achieve nanometer precision using flexures. It shows a 3D-printed replica and how one motor handles both coarse and fine motion.

A Blender-animated explanation of the Toyota Hybrid Synergy Drive, showing how the engine, two motor-generators, planetary gearset and battery work together as an eCVT.

Tom Scott explains why confetti and snow wreck video quality, using interframe compression and bitrate. He demonstrates it live by changing the quality on screen.

A PBS Space Time episode explaining the holographic principle: the idea that our 3+1 dimensional universe may be described by information on a lower-dimensional boundary. It walks through black hole entropy and the AdS/CFT correspondence.

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.

An episode of Coding Secrets by Jon Burton on retro copy protection, in particular physically damaging a disk with a laser so copies fail. It explains how this defeated hackers and pirates.

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.

Chuck Marohn of Strong Towns explains how a land value tax differs from an ordinary property tax, why it makes economic sense, and why it is rarely used. It is a short six-minute explainer.

Numberphile's James Grime discusses highly composite numbers, nicknamed anti-primes, which have more factors than any smaller number, using 5040 as the central example. It touches on Plato and Ramanujan.

A Vox reporter tries to learn what his son's birth would cost before it happens and fails, showing how opaque US hospital pricing is even for the most common procedure.

Primer simulates green beard altruism, where individuals recognize and help others carrying a shared marker, and shows how imposters affect its evolution. It is an animated evolution simulation based on published papers.

A Wendover Productions explainer on how airport security is designed, covering screening layers, x-ray scanning, and the contrast with Israel's profiling-based approach. It walks through the logic behind why security works the way it does.

Practical Engineering gives a short introduction to concrete, covering the difference between concrete and cement, the ingredients, and reinforcement. It includes a hydraulic press demonstration of compressive strength.

A short RepresentUs explainer arguing that US politics is shaped by money, citing the Gilens and Page Princeton study on how little average citizens influence policy.

Practical Engineering explains how canal locks work, including the water-saving basins of the new Panama Canal locks.

Wendover Productions explains counterintuitive riot control techniques based on research, showing that effective tactics tend to avoid violence.

Tom Scott explains for Computerphile why handling time and timezones in code is so hard, walking through a simple web app that computes how long ago something happened. It covers the quirks of timezones and calendars and ends in an exasperated rant.

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

An Extra Credits episode on China's Sesame Credit, which gamifies obedient citizenship through a social score. It covers how the system rewards conformity and pressures people through their friends' behavior.

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.

Tom Scott explains Gricean maxims, the unwritten guidelines that shape how we understand each other. He uses examples such as why 'asbestos-free cereal' sounds suspicious.

Numberphile interviews Grant Sanderson of 3blue1brown about Bertrand's paradox, where different reasonable ways of picking a random chord of a circle give different probabilities.

PBS Space Time asks whether dark matter could be made of primordial black holes. It walks through the observational constraints that limit this idea.