rs-25

A 1953 US Navy training film on the basic mechanisms in fire control computers: shafts, gears, cams and differentials. It shows how these mechanical parts compute ship and target firing solutions.

John Scholes builds a depth-first tree-search operator step by step in a Dyalog APL session. It covers higher-order functions and runs the search on the N-Queens problem.

Ben Eater shows how to build logic gates out of transistors, including NOR gates. It is part of his clear hardware-from-scratch teaching style.

Anders Brownworth gives a basic visual introduction to blockchain using an interactive web demo, covering SHA256 hashes, blocks, chains, distribution, tokens and coinbase transactions.

A 1930s Chevrolet training film explaining the principles and development of the differential gear. It builds the idea step by step from first principles to the finished mechanism.

A 12-minute beginner lesson from Nick Milo's Linking Your Thinking series introducing the Obsidian note-taking app and the first steps to start using it.

A guided Wim Hof breathing session of three rounds at a slow pace, building from a 30 second to a 90 second breath hold. An on-screen bubble animation helps you keep the rhythm.

A short video of stretching and hand exercises for preventing and easing tendinitis and carpal tunnel syndrome, from a percussion teacher. The exercises were shown to him by a doctor.

A motorcycle safety video on the SMIDSY (sorry mate, I didn't see you) accident, explaining the perception and optical illusion that makes drivers fail to see riders, and how riders can spot the signs and avoid it.

A beginner-focused tutorial on freehand knife sharpening with a single stone, aiming for a shaving-sharp edge in about five minutes.

An episode of FunFunFunction explaining monads in JavaScript as functors that also implement flatMap. It builds on the preceding functor episode and works through code examples.

ElectroBOOM's Mehdi Sadaghdar explains how a full bridge rectifier works, the building block of AC to DC converters, with his usual humor and a demonstration of the circuit.

DIY Perks builds a webcam mod using a two-way mirror in a box so the camera sits behind the screen image. This allows real eye contact on video calls.

A Harvard Business Review video with tactics for getting better at small talk and enjoying it, such as setting goals, allowing pauses, and starting and ending conversations.

Jeri Ellsworth shows step by step how to make an NMOS transistor at home using a kiln, rust remover, spin-on dopant, eBay wafers and vinyl stickers.

Bisqwit writes a raytracer from scratch in C++ for DOS, rendering in the 16-color VGA palette at 640x480. The video also covers color quantization and ordered dithering.

Inigo Quilez shows step by step how to build a simple heart shape from mathematics and shaders, with code on Shadertoy. It is an introduction to procedural graphics and signed distance functions.

A screencast showing how to use the fzf command-line fuzzy finder in the shell and in Vim. It covers searching files and also using the Vim plugin for help tags, buffers, lines and grep matches.

DIY Perks shows how to modify devices that use older USB connectors so they charge and connect over USB Type-C. He solders in a USB-C connector board and works through cases such as dongle-dependent gadgets and a mouse receiver.

Acerola explores building a shader that turns games into ASCII art, walking through techniques such as brightness mapping and edge detection to see whether it looks good.

The first episode of Google's Machine Learning Recipes series. It introduces machine learning and builds a first supervised-learning classifier in about six lines of Python using scikit-learn.

A guide to charging a non-Tesla EV, here a BMW i4, at a Tesla Supercharger in the UK, with do's and don'ts. It shows the process in practice now that the network is open to all cars.

A short screencast tour of JSPM, SystemJS and ES6 features, building a small app with the then-new JavaScript module and package tooling. It shows how JSPM works as a package manager, bundler and loader.

James Hoffmann demonstrates his AeroPress technique with a short recipe: 11g of coffee, 200g of just-boiled water, a 2-minute immersion, then a press. He explains why he skips rinsing, preheating and inverting.

Mathologer shows a simple idea, the commutator, that lets anyone who can solve the first layer design their own full Rubik's cube solution. The same idea carries over to other symmetric twisty puzzles such as the Megaminx.

A step-by-step guide to building a lifter, a small triangular ionocraft made from balsa wood, aluminum foil and thin wire, powered by a high-voltage supply. It also shows high-voltage safety practices.

Jeri Ellsworth shows early steps of making microchips at home: cleaving wafers, removing native oxide, testing dopant type with a hot probe, and loading the furnace.

In this American Masters clip, Jacques Pepin shows two different techniques for making a perfect omelet, a dish he is famous for teaching America.

Bisqwit writes a NES emulator in C++ in about 15 minutes of tool-assisted, sped-up coding, narrated with captions. It shows an accurate emulator built with a compile-time generated 6502 instruction table. Part 2 covers compiling and running it.

First of a three-part tutorial series on the i3 tiling window manager for Linux. It explains what i3 is, how to install it on Ubuntu, and how to use it.

Blender Guru's beginner tutorial series, in which you model, light, texture and render a donut while learning Blender's core features. This is Part 1 of the Blender 3.0 version.

Essential Craftsman announces the start of a spec house build on a scenic lot, kicking off a long series. The channel covers every step of building a house from the viewpoint of a general contractor.

A short first episode in Zaiste's Doom Emacs series, showing how to get started with Doom, an Emacs configuration aimed at Vim users. It presents Doom as a polished, fast, batteries-included distribution.

The first episode of a screencast series building djb's redo build system from scratch in Haskell. It explains the purpose of redo, writes initial code and sets up a GitHub repository.

The first part of a series on programming in Jai, Jonathan Blow's in-development language. It covers compiling, writing hello world and using code from other files.

Lock-picking YouTuber Bill Johnson (BosnianBill) explains how to choose a high-security lock and why, showing examples and comparing designs. It covers what makes some padlocks more pick-resistant than others.

The Thought Emporium shows how to receive clear images directly from GOES-15, 16 and 17 and Himawari 8 geostationary weather satellites with software-defined radio. It covers the extra effort needed to receive GOES data.

CuriousMarc inspects a newly arrived Teletype Model 19, an early military unit built around a Model 15 keyboard and printer, after an initial rough cleaning. It is the first part of a restoration series and touches on 5-bit Baudot code.

This Old House's Ross Trethewey explains MERV filter ratings and how air filtration works, then shows how to build a localized DIY air filter, including a box fan with multiple filters.

The 8-Bit Guy explains how character LCD screens work and how to control them directly, first part of a series.