epa

Tom Scott explains why Britain historically has separate hot and cold taps rather than mixer taps, tracing it to how water was stored in tanks. He notes why the hot tap is not safe to drink from.

Big Clive takes apart an IKEA Koppla USB power supply to assess its safety, looking at isolation and transformer construction.

A 1936 Chevrolet-sponsored film that explains how a car transmission works by treating gears as spinning levers. It uses physical models to make the mechanism clear.

Engineering Explained works through whether electric cars are really worse for the environment than gasoline cars. It covers battery production emissions, the electricity mix used to charge, and how long an EV takes to break even on lifetime emissions.

Real Engineering examines the efficiency of hydrogen as an energy carrier. It follows production, storage and fuel cell conversion losses and compares hydrogen cars with battery electric vehicles.

A Blender-animated explanation of the Toyota Hybrid Synergy Drive, showing how the engine, two motor-generators, planetary gearset and battery work together as an eCVT.

FortNine's tongue-in-cheek guide to why drivers fail to see motorcyclists and how riders can make themselves more visible. It touches on perception psychology, including the role of saccades.

Technology Connections explains why North American tail light rules, which allow red turn signals and flashing brake lights, make signals ambiguous. He argues for amber signals and cites studies showing a safety benefit.

Engineering Explained uses physics to show why today's electric cars, including Teslas, are poor at towing, pointing to battery energy density and weight. It examines Cybertruck and F-150 towing claims.

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.

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.

FortNine argues that the US DOT motorcycle helmet standard (FMVSS 218) is badly outdated and weak. It compares it with Snell and ECE standards and points to where you can look up test reports for your own helmet.

NFPA video in which wildfire researcher Jack Cohen explains that embers (firebrands), not the flame front, are the main cause of homes igniting in wildfires. He shows how landscaping and removing debris around the home reduce risk.

Arthur Keller gives a roughly half-hour crash course on environmental collapse, covering exponential growth, carrying capacity and ecological overshoot.

CGP Grey explains that the City of London is a tiny, separate entity with its own governance, history and privileges, distinct from the city called London. He covers its financial role and how it is run.

Robert Miles explains the orthogonality thesis: how an agent can be highly intelligent while pursuing goals that seem stupid or alien to humans. He separates intelligence from goals and touches on the stamp-collector example.

3Blue1Brown shows how the uncertainty principle arises from Fourier transforms. A wave packet cannot be narrow in both position and frequency, so the principle is a property of waves rather than of measurement.

Part 3 of Kirby Ferguson's Everything is a Remix series, using Apple and the iPhone to show how invention builds on copying and combining prior ideas. It argues that creativity and innovation are inseparable from copying.

Numberphile with Tadashi Tokieda on the Trinity Hall Prime, a prime number whose digits form a picture of the college's coat of arms, left as a gift by a departing mathematician.

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.

Illumina's 3D animation of its sequencing-by-synthesis workflow, from sample preparation and cluster generation to sequencing on a flow cell and data analysis.