differential pairs

Rick Hartley's AltiumLive keynote on differential pairs in PC boards. He argues the rules from cables and twisted pairs do not carry over, and covers which pair geometry gives the best impedance control, the right spacing, routing practice and how much skew is acceptable.

A 1937 GM-produced film explaining how the automobile differential lets wheels turn at different speeds around a corner. It uses clear animations and cutaway demonstrations to build the idea from first principles.

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.

Neil Fraser of Google presents Differential Synchronization, the algorithm behind MobWrite, for keeping multiple copies of a document in sync in real time. The talk argues the approach is robust, convergent and efficient.

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.

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.

CityNerd lays out a data-driven method for deciding where high-speed rail should be built in North America and identifies 56 city pairs that justify it, based on population and distance.

A short video illustrating the hazard of pressure differentials (delta P) in commercial diving, where a pressure difference creates enormous force on a diver. It is a safety-oriented look at diving accidents.

The first of an eight-part ScienceClic series building general relativity, covering worldlines, proper time and coordinate systems with animated visualizations.

A 1953 US Navy training film explaining the basic mechanisms in mechanical fire control computers aboard ships. It shows how gears, differentials and cams solved mathematical problems in permanent mechanical form.

Tim Hutton's demonstration of SmoothLifeL, a continuous version of Conway's Game of Life using floating point values. It shows gliders traveling in any direction, rotating pairs, and elastic cord-like structures, with config details to run it yourself.

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.

Morten Rand-Hendriksen's WordCamp Europe 2017 talk presents CSS Grid Layout as a native two-dimensional layout system that changes how web pages are structured, including responsive layouts independent of source order. It was given as browsers began shipping support.

The first lecture of David MacKay's Cambridge course on information theory, pattern recognition and neural networks. It introduces the core ideas of his book Information Theory, Inference, and Learning Algorithms.

Course outline for Stanford's online GNSS course, introducing how GPS works and the many uses of satellite navigation. The series pairs short lectures with backyard experiments using smartphones.

Louis Rossmann argues that reballing flip-chip GPUs is not a real fix for dead laptop GPUs. He explains why such repairs and oven reflow tricks fail and what is actually happening with failing hardware.

A short scene from Malcolm in the Middle in which Hal tries to fix a light bulb and is pulled into a growing chain of side repairs.

Richard Ankrom's account of his 2001 guerrilla project, in which he painted and installed a missing freeway exit sign on a Pasadena freeway. The sign matched official standards and stayed up for years before being discovered.

A short clip of Richard Feynman explaining how a train stays on its tracks, through the conical shape of wheels and how it handles curves without differentials.

Louis Rossmann reacts to a CBC News segment in which an Apple Genius Bar quoted a costly logic board and display replacement for a MacBook that had only a bent pin. He explains why the repair is simple and what the case shows about Apple's repair practices.

Tom Gally, a former professional translator and University of Tokyo professor, discusses in March 2023 whether GPT-4 and similar models could translate literary and popular fiction. He gives his assessment of Japanese-to-English quality.

Louis Rossmann visits Apple Authorized Service Providers to see what repairs they can actually do. He finds, for example, that an iPhone 6 headphone jack is not repairable and requires an expensive board replacement.

A CBC The National investigation into Apple's business practices, including undercover work on repair pricing and the battery slowdown scandal. It examines allegations of overpriced repairs and misdiagnosis.

A short animation that pairs the sound of a dialup modem handshake with a graphic explaining what each phase of the sound means.

Rick Beato tests his 8-year-old son Dylan's perfect pitch on single notes, note pairs and complex polychords.