code density

CGP Grey explains that postal codes are routing instructions for mail rather than geographic regions. He looks at the quirks and problems this causes.

3Blue1Brown's discovery-oriented introduction to error correction codes, building up Hamming codes from the puzzle of locating a flipped bit. It explains the parity-check idea and why it is so efficient.

Veritasium builds a QR code by hand to explain how it works. It covers the history of Morse code and barcodes, how QR codes encode data, why damaged codes still scan, and how safe they are.

Tom Scott explains for Computerphile how Unicode and UTF-8 grew out of messy older character encodings to become the web's standard. It covers why the design works and how it handles worldwide text.

8-Bit Show And Tell walks through the BASIC source code of the original Commodore 64 Sid Meier's Pirates!. It covers bugs, quirks and traces of abandoned features and scenarios left in the code.

Matthias Wandel tests old and new code on a range of PCs, including a new mini PC, to measure how much faster modern hardware really is. He also shows optimization techniques such as branchless code, with benchmark programs on GitHub.

CGP Grey explains why airport codes are inconsistent and sometimes confusing, from their origins in old weather station codes to the quirks that cause mistakes. He builds the story around a single typo that sent a flight to the wrong continent.

Matt Parker follows the community effort to speed up his slow Wordle-solving code, which ended up running hundreds of millions of times faster. He walks through the techniques contributors used.

CodeParade's short devlog on how spherical geometry looks in 2D and 3D and why it feels so unusual, part of the Hyperbolica series on a non-Euclidean game.

Kaze Emanuar explains how he rewrote and optimized the Super Mario 64 source code so it runs far faster on real N64 hardware. He covers performance bottlenecks and fixes in detail for his ROM hacks.

Oh The Urbanity! argues that most city dwellers live in dense residential neighbourhoods outside downtown, which can be calm and peaceful. It draws on older, denser parts of Toronto and Montreal.

Numberphile's Dr James Grime explains the flaw in the Enigma machine, namely that a letter could never be encrypted to itself, and how that helped the Allies break the code. It touches on the Bombe and Alan Turing.

Not Just Bikes takes on the common excuse that a country is simply too big or spread out for good transit and walkable cities. The video argues that city density and short everyday trips matter, not national size or overall population density.

Real Engineering analyzes whether electric planes are feasible, focusing on battery energy density limits compared with jet fuel. It concludes electric flight works mainly for short ranges.

Engineering Explained uses physics to show why today's electric cars, including Teslas, are poor at towing, pointing to battery energy density and weight. It examines Cybertruck and F-150 towing claims.

A Two Minute Papers episode on NVIDIA's recurrent denoising autoencoder, which cleans up noisy Monte Carlo path-traced image sequences. It shows how a neural network can produce usable renders from very few samples.

About Here explains how North American building codes requiring two staircases make small multi-story apartment buildings hard to build, and contrasts this with places that allow single-stair designs.

A speedrunner-made explanation of the Super Mario World credits warp, an arbitrary code execution glitch that jumps the game straight to the ending. It simplifies the underlying assembly and memory behavior with animations so non-experts can follow.

Not Just Bikes contrasts traditional and suburban development in North America. It looks at the financials behind each pattern and argues that suburban development leaves cities unable to pay for their own infrastructure.

Not Just Bikes explains why living in a dense, bikeable Dutch city sharply reduced his family's environmental footprint and improved quality of life. It is a collaboration that continues on Climate Town.

Marcus du Sautoy of the BBC demonstrates the wisdom of the crowd, showing that averaging many guesses of jelly beans in a jar lands near the true count.

LearnCode.academy presents a roadmap of web development technologies to learn in 2016 and 2017, spanning front-end, back-end and DevOps tools.

Not Just Bikes explains missing middle housing, such as duplexes, townhouses and small apartment buildings. The video argues that zoning in the US and Canada has made these options almost illegal.

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.

Not Just Bikes explains the Strong Towns argument that car-dependent American suburbs cost more to maintain than they generate in taxes. It describes the growth Ponzi scheme that props up municipal finances.

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.

Wendover Productions explains why US passenger rail lags behind other countries. It covers freight companies owning most of the track, geography and population density, and the economics of competing with flying.

Ward Cunningham explains the history and intent of the debt metaphor, which he coined while refactoring the WyCash product. He says debt means code reflecting an incomplete understanding of the problem, not sloppy programming.

Climate Town gives a comedic, fast-paced account of how the plastics industry promoted recycling, including the resin-code recycling symbol, while knowing most plastic could not be economically recycled. It points viewers to the Frontline documentary Plastic Wars for a deeper treatment.

Polylog explains how algorithms can be turned into circuits and encoded as satisfiability problems, which lets you effectively run them backwards. It uses this to motivate breaking RSA, general reductions to SAT, and what P vs NP is really asking.

A step-by-step animated explanation of how SHA-256 works, from padding and message schedule to the compression function and final hash, with source code for the animations.

Benn Jordan's video about storing a PNG image in a living bird, a starling that learns to reproduce encoded sounds. It mixes ornithology, audio engineering, and data encoding.

PBS Space Time episode on the black hole information paradox, covering how black holes seem to destroy information, the no-hair conjecture and the proposed role of the event horizon. It is part of a series on black holes.

Not Just Bikes explains that car-dependent suburbs are not the only option, using Toronto's Riverdale as an example of a pre-war streetcar suburb. These walkable neighborhoods are popular but are now effectively illegal to build.

Veritasium examines whether food has become less nutritious, weighing soil depletion, selective breeding and rising atmospheric CO2. It evidences nutrient decline even in weeds over a century and ties it to faster plant growth.

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.

Kurzgesagt explores the idea that black holes could create universes and that we might live inside one. It builds up the physics of how density falls as black holes get larger.

Tom Scott explains YouTube's 11-character video IDs, which are base-64 encoded 64-bit numbers, and whether YouTube could ever run out of them. It covers counting systems and base 64 briefly.

A guest video by Welch Labs on 3Blue1Brown explaining how text-to-image and video models work. It covers CLIP, shared embedding spaces, diffusion models (DDPM, DDIM), conditioning, guidance and negative prompts.

A short Nature video on the discovery that our home supercluster is Laniakea, redefined by mapping the flow of galaxies rather than their density. It names the structure with a Hawaiian word meaning 'immeasurable heaven'.