speed

PBS Space Time argues that the speed of light is better understood as the speed of causality, the universal limit on how fast cause and effect propagate. Light travels at that speed because it is massless, but the limit itself is a property of spacetime.

ScienceClic explains why nothing can go faster than light by treating motion through space and time together, so everything moves at the speed of light through spacetime. It uses animated visuals to cover relativity basics in 12 minutes.

Thunderf00t presents high-speed camera footage of alkali metals such as sodium and NaK reacting with water. The footage shows that the explosion is not caused by hydrogen ignition, as the usual explanation says. It is a Coulomb explosion driven by electrons leaving the metal.

Veritasium explores why time seems to speed up as we age, covering chronoception and several competing explanations beyond the common proportional-theory argument.

PBS Infinite Series explains how Shor's algorithm lets a quantum computer break RSA encryption, building on earlier episodes about cryptography and the math of quantum computers. It works through the idea step by step.

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.

Pannenkoek2012's commentated tool-assisted Super Mario 64 run collecting the Watch for Rolling Rocks star with half an A press, using parallel universes and QPU movement. The video is marked outdated in favor of a newer version.

Pannenkoek explains how Super Mario 64 handles wall, floor and ceiling collisions, including triangles, normal vectors, quarter steps and out of bounds. It is a detailed 37-minute technical walkthrough of the game's physics.

A Wendover Productions explainer on how China built the world's largest high-speed rail network so quickly and why its rail strategy differs from America's. It covers politics, social benefits and the economics of unprofitable lines.

Tom Scott visits Peachtree City, Georgia, which has about a hundred miles of dedicated golf cart paths that serve as an alternative to driving. He explains how the network works as a quasi-transit system that keeps cars off the roads.

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.

An episode of Coding Secrets by Jon Burton on retro copy protection, in particular physically damaging a disk with a laser so copies fail. It explains how this defeated hackers and pirates.

3kliksphilip summarizes Valve's GDC talk on VACNet, a deep-learning system that flags CS:GO cheaters and feeds the Overwatch review queue. It covers Trust Factor, VAC, and how the data is collected and analyzed.

Numberphile's Ben Sparks works through the physics of a car crash, showing how kinetic energy grows with the square of speed and why stopping distance climbs so quickly as velocity increases.

CGP Grey explains how traffic jams come from human driving behavior such as tailgating and reaction delays, and how leaving gaps and smoothing speed would reduce congestion. It also touches on self-driving cars.

A Wendover Productions explainer on why train tickets, especially Amtrak in the US, cost so much compared with flying. It breaks down staffing, speed and the cost components behind a ticket.

Destin of Smarter Every Day films a cat falling in high-speed slow motion to show how cats right themselves in midair, and introduces the physics behind it.

A short BicycleDutch video on how the Netherlands got its cycling infrastructure, including the 1970s protests and the shift away from car-centric planning. The channel later published an updated version.

A four-minute Not Just Bikes comparison of grocery shopping in Amsterdam versus car-centric North America, arguing that frequent small fresh-food trips beat bulk shopping. It ties this to land use and reduced food waste.

Technology Connections explains how LED traffic lights, which do not melt snow, drew complaints and were blamed for accidents. He uses it to illustrate the 'but sometimes' fallacy against new technology.

The first episode of a Cities: Skylines series on urban politics and planning, focused on parking. It uses the game to show how parking minimums shape cities, drawing on Donald Shoup's book The High Cost of Free Parking.

The School of Life sets out principles for making attractive cities, arguing that the art has been lost in the modern world.

A short BicycleDutch episode showing how people with disabilities use Dutch cycle tracks on hand-cycles, tricycles and mobility scooters.

A short Not Just Bikes video on continuous sidewalks in the Netherlands, where the sidewalk runs unbroken across side streets so cars must visibly cross pedestrian space. It places them within Dutch sustainable safety and Vision Zero efforts.

A mini-documentary by a Canadian living in Japan explaining how an average family can afford a new detached house in Tokyo. It covers how houses are treated as depreciating assets and how Japanese zoning and building practices keep prices low.

Not Just Bikes explains the Dutch concept of autoluw, or nearly car-free, streets and how it is applied across the Netherlands, with examples from Toronto and Copenhagen. It also covers Amsterdam's move toward a nearly car-free city.

An MTA video on communications-based train control, the system meant to replace the New York City subway's century-old signaling. It also shows the mechanical interlocks and signals in use today.

Chuck Marohn of Strong Towns explains how a land value tax differs from an ordinary property tax, why it makes economic sense, and why it is rarely used. It is a short six-minute explainer.

A short Not Just Bikes video on the 1960s plans (Plan Jokinen) to cut highways through Amsterdam to accommodate cars. It shows how radically different the city would look had they succeeded.

A short BicycleDutch episode showing how Dutch protected intersections continue cycle paths through the junction without needing extra street width.

A five-minute BicycleDutch episode showing how Dutch junctions are designed so cyclists and pedestrians can cross safely. It explains the layout choices that separate and protect them.

A Vox Borders explainer on Hong Kong's housing crisis, the least affordable market in the world, and the tiny cage homes and subdivided flats people squeeze into. It looks at why prices keep climbing and how land policy contributes.

Geoff Marshall explains a running gag about London Underground stair signs claiming that the climb equals 15 floors, regardless of how many steps there actually are.

A short BicycleDutch episode showing how Dutch junctions with protected cycle paths are laid out. It argues these are proven, non-experimental designs that make intersections safer for cyclists.

A Vox explainer on how mandatory parking minimums and free parking impose hidden costs on cities. It draws on Donald Shoup's work and gives the history of parking requirements.

Tom Scott and Matt Parker investigate some of the small deceptions and oddities of the London Underground, such as misleading signage and map distortions.

A short Vox video on Barcelona's superblocks, an urban design approach that closes interior streets to through traffic to return space to pedestrians.

Fermilab's Don Lincoln explains why light travels slower in water and glass. He knocks down common wrong explanations such as absorption and re-emission, then gives the wave-mechanics reason tied to refractive index.

Professor Mike Merrifield of Nottingham explains in a mostly uncut conversation why light travels slower in glass. He treats light as a wave and describes how the material's electrons produce secondary waves that combine to slow it.

Cody's Lab builds a 200-billionth-scale model to show how far away the nearest stars are, using parallax and light speed. A short astronomy explainer on interstellar distances.