at&t

A 1951 Bell System training film showing how telephone calls are routed through a step-by-step (Strowger) switching office.

Mathologer shows how times table diagrams on a circle produce cardioids and other curves connected to the Mandelbrot set. He explains the patterns and links to a tool for making your own diagrams.

Matt Parker of Stand-up Maths examines scatter plots that were claimed to show fraudulent vote-switching in Michigan's 2020 election. He recreates the analysis and shows that the pattern arises from comparing percentages across different bases, not from fraud.

A two-minute explanation of what a rocket mass heater is, starting from how a conventional wood stove works and why creosote and chimney fires occur. It shows how burning hot and storing the heat in thermal mass makes for an efficient heater.

Branch Education explains how Starlink works, from the ground dish and satellites to phased-array beam steering and data routing. Animations cover how a beam stays connected to a satellite moving at 27,000 km/h.

Matt Parker of Stand-up Maths explains single-pile Nim and the trick that wins it, using Dr NIM, a 1960s mechanical plastic computer that plays perfectly. He teaches the strategy so viewers can beat friends.

Matt Parker of Stand-up Maths examines the Texas Supreme Court filing claiming Biden's 2020 win had a one-in-a-quadrillion chance. He walks through why the statistical argument is flawed.

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.

An RSA Animate whiteboard adaptation of Dan Pink's talk on what motivates people at work. It argues that beyond simple tasks, autonomy, mastery and purpose drive performance more than money.

Technology Connections explains why heat pumps matter right now, covering their efficiency, how they hold up in cold weather and the energy savings over burning fuel. It follows his earlier explainer on how they work.

A Technology Connections video on how ground-source (geothermal) heat pumps work and why they hold efficiency in winter. It also covers related heat pump information, and the description notes air-source heat pumps have since improved.

3Blue1Brown builds visual intuition for quaternions, showing how to think about this four-dimensional number system using stereographic projection and rotations in 3D space. It is part one of a two-part series with an interactive companion site.

Potholer54 presents the climate science case and a market-oriented, conservative-friendly approach to addressing global warming, with sources listed. It is part one of a two-part series.

Kurzgesagt's animated take on climate change argues that, despite alarming headlines, there are real reasons for hope as technology, policy and public attitudes shift. It surveys trends and solutions while acknowledging the scale of the problem.

Technology Connections' long closing video in his heat pump series, arguing that adopting heat pumps is well within reach. It explains how they work and what it takes to start using them.

An animated 11-minute tour of the whole field of mathematics as a single map, showing how pure and applied math and their sub-fields relate to each other.

3Blue1Brown's visual walkthrough of the attention mechanism inside transformers, covering self-attention, multiple heads and cross-attention. It is chapter 6 of his deep learning series.

Numberphile's Ben Sparks shows why the golden ratio is the most irrational number, using seeds, continued fractions and rational approximations. He also explains why plants use it for spacing leaves and seeds.

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.

The first video in potholer54's climate series, giving a basic look at how climate scientists infer that man-made carbon gases are changing the climate. It is a short explainer meant to present the scientific evidence plainly.

Kurzgesagt examines who is responsible for climate change, comparing historical, current and per-capita emissions by country. It argues that individual footprints are a distraction from larger responsibility.

Eager Space examines the practicality of putting data centers in orbit, walking through three scenarios with cost calculations and the launch cost reductions that would be required.

Animator Noodle explains why frame interpolation does not make animation better, covering timing, easing, smear frames and using the wrong tool for the job. A pinned correction says the video is partly outdated given later AI developments.

A video essay from Every Frame a Painting on animator Satoshi Kon and his editing style, which distorts and warps space and time. It draws on his four features and one TV series.

An episode of Journey to the Microcosmos, hosted by Hank Green, about diatoms, single-celled algae with glass shells. It covers their role in producing a large share of Earth's oxygen and their uses in beer filtering, paint and kitty litter.

Alex O'Connor shows that ChatGPT cannot draw a wine glass filled to the brim, and ties the failure to David Hume's missing shade of blue. It asks what the failure says about how image models learn.

Sabine Hossenfelder explains that waste heat from ever-growing energy use could eventually boil the oceans in a few centuries, whatever the energy source. She discusses proposed ways to cool the planet.

Scott Manley examines why SpaceX, Google and others are looking at orbital data centers. He walks through the economics, heat rejection and solar power arguments, with links to the Lumen/Starcloud and Google Suncatcher papers.

Scott Manley explains the thermal balance of spacecraft and how a satellite could be configured to radiate away the heat from datacenter-scale computing in space. His rough numbers suggest it is feasible.

Vsauce explores math through card tricks and big numbers, including an animation of how enormous 52 factorial, the number of deck orderings, really is.

An animated adaptation of Captain David Marquet's talk on greatness, based on his book Turn the Ship Around!. It argues for pushing decision-making down to the people doing the work instead of controlling everything from the top.

Tom Scott explains for Computerphile how floating point numbers work, why moving the binary point is fast, and why it handles money badly.

Scott Manley analyzes the idea of putting data centers in orbit, prompted by Lumen Orbit's funding. He examines the claimed advantage of constant solar power against launch cost, cooling and mass.

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.

Scott Manley explains rotating detonation engines, how they differ from pulsed detonation engines, and why thermodynamics predicts they beat traditional jet and rocket engines.

JerryRigEverything tours Li-Cycle to show how lithium-ion batteries from EVs, phones and tools are recycled. It walks through the process of shredding batteries and extracting materials.

3Blue1Brown uses Wordle as an excuse to teach information theory and entropy, building a solver that picks guesses by expected information and incorporating word frequencies.

Sabine Hossenfelder explains climate sensitivity and why recent observations suggest climate models may have underestimated warming. She says this changed her view on how worried to be.

Corridor Crew dive into the visual effects of Terminator 2 and try recreating the T-1000 bars scene with modern tools. They explain how the original effects were achieved.

Technology Connections explains how an ordinary tank water heater works, including twin-element designs, and why it is cleverer than it looks.