soldered ram

Dave Plummer tours the IBM z16 mainframe from design through factory assembly, test lab, accelerators and water cooling. He explains why mainframes still exist and what makes them reliable.

Matt Parker explains the history behind NTSC television running at 29.97 frames per second rather than 30, tracing it to the backward-compatible addition of color. He walks through the arithmetic behind the odd ratio.

3Blue1Brown explains how holograms record a 3D scene on 2D film, using wave diffraction and phase. The video includes demonstrations of several real holograms.

Linus Tech Tips reviews the first Framework Laptop, a fully repairable and upgradeable machine. The reviewer expected a flimsy chunky device and was happily surprised.

Mathologer examines how identities like 1+2+3+... = -1/12 arise in Ramanujan's work, starting from his 1913 letter to Hardy. The video explains the rules for summing infinite series and why such results are meaningful but not naive sums.

Adam Neely tests the claims for tuning to A=432 Hz by trying the unusual tuning systems that its proponents' numerology requires. He compares how they sound against standard tuning and temperaments.

Veritasium explains why the kilogram is being redefined in terms of Planck's constant rather than a physical metal artifact. It visits NIST to show the Kibble balance and why measuring mass precisely is hard.

Tom Scott-style exploration by suckerpinch (Tom7) of generalized anagrams where letters can be broken into pieces, called anagraphs, with a whimsical computational approach.

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 A pinned correction says the video is partly outdated given later AI developments.

Cleo Abram's explainer on whether nuclear waste is really the intractable problem it is portrayed as, looking at how spent fuel can be recycled and used. It features a collaboration with Johnny Harris.

MinutePhysics, with 3Blue1Brown, explains Bell's theorem using a Venn diagram paradox and polarizing filters. It shows why no local hidden variable theory can reproduce quantum correlations.

Veritasium explains the effort to redefine the kilogram, which was still defined by a physical artifact, and how a near-perfect silicon sphere from the Avogadro project helps. It also covers the history of the unit's odd naming.

A Wendover Productions explainer arguing that major airlines make much of their profit from loyalty programs and co-branded credit cards rather than flying. It frames airlines as quasi-banks that sell points in bulk, using United's pandemic-era loan as a hook.

PBS Space Time explains what happens as you approach and cross a black hole's event horizon, using Penrose diagrams and light cones as the tool for understanding spacetime there.

Tom Scott argues that grammatical gender is a silly concept and that the singular 'they' is an established gender-neutral pronoun. The description carries later corrections and reflections he added in 2019.

Mick West shows new night-vision reference footage indicating the Navy's supposed flying pyramid UFO is just an out-of-focus light, likely a plane near LAX, rendered triangular by bokeh. He identifies other lights as Jupiter and stars.

Veritasium explores what general relativity says about black holes, white holes and wormholes, with help from physicists Geraint Lewis and Juan Maldacena. It introduces Penrose diagrams and the idea that other universes may be implied.

AlphaPhoenix uses a custom high-speed measurement setup to watch voltage waves travel down wires and split at a fork. It answers how electricity knows where to go and how quickly that process happens.

A 36-minute animated deep dive from Branch Education into how DRAM works. It shows how memory connects to the CPU and how billions of bits are stored in nanoscale capacitor cells. It also covers why DRAM sits between SSDs and the processor.

A PBS Space Time episode hosted by Gabe Perez-Giz on the nature of spacetime and whether space and time are fundamental. It builds up reference frames and causality in a short, dense format.

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.

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 minutephysics video explaining why a piano cannot be perfectly tuned, comparing equal temperament with just intonation and the math of harmonics.

Musician Adam Neely examines whether certain keys sound sadder than others, looking at the history of tuning systems and temperaments and at how instrument timbre shapes the emotional character we hear. It draws on historical aesthetics writing and audio examples.

A PBS Space Time episode explaining why faster-than-light travel is equivalent to travelling back in time, using relativity and Minkowski diagrams for different observers.

Retro Game Mechanics Explained shows how the Atari 2600 draws images with almost no video memory, by having the CPU race the CRT beam line by line. It walks through the techniques in detail.

A short explainer from Nat and Friends on where Google Earth's 3D imagery comes from, how it is stitched together, and how often it is updated. It describes aircraft carrying camera rigs and photogrammetry that turns the photos into 3D models.

A Half as Interesting explainer on the US program that drops millions of sterile screwworm flies over Panama every week to keep the parasite out of North America.

2swap explores lambda calculus using John Tromp's lambda diagrams, with animated beta-reductions, asking what PLUS times PLUS gives. It touches on Church encodings and the equivalence of Turing machines and lambda calculus.

Veritasium explains that the US signed the Metre Convention in 1875 and that all US customary units are officially defined in terms of metric standards. It also touches on the standard kilogram.

Every Frame a Painting analyzes how Jackie Chan stages action comedy, with nine principles such as starting from a disadvantage, using the environment, clear shots, and keeping action and reaction in the same frame.

An Every Frame a Painting video essay on how Akira Kurosawa used movement, weather and composition to tell stories. It draws on clips and interviews with other filmmakers.

A video essay from Every Frame a Painting about Vancouver, a major film production city that almost never appears onscreen as itself. It shows clips of films and TV shot there that pass the city off as somewhere else.

An Every Frame a Painting video essay on Michael Bay's style, 'Bayhem', covering his camera movement, composition, color and editing. It argues that even if you dislike his films, they teach something about visual perception.

An Every Frame a Painting video essay analysing how Edgar Wright creates visual comedy through framing, camera movement, editing, sound effects and music.

An Every Frame a Painting video essay on Buster Keaton's visual comedy, examining how he built and framed his gags. It uses clips from his silent films to show the thinking behind them.

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.

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.

Ben Felix explains how to compare renting and buying a home by looking at unrecoverable costs, and distills it into the 5% rule of thumb. It is framed for a Canadian audience but broadly applicable.

Mathologer examines the infamous Numberphile claim that 1+2+3+... equals -1/12, explaining what is wrong with the calculation and how it connects to real math like the zeta function and analytic continuation.