unit testing

A SAAMI-produced training video for firefighters explaining what happens when sporting ammunition burns, including that unchambered cartridges lack the energy to penetrate much. It includes test footage of ammunition in fires.

Destin of Smarter Every Day goes behind the scenes at the 23andMe lab to show how genotyping works. He also discusses DNA testing and privacy.

Veritasium tells how Kodak film was fogged by radioactive fallout from the first atomic tests, letting the company detect nuclear testing before anyone announced it. The video also covers the deal to keep it quiet and how fallout contaminated packaging.

Dr. John Campbell reviews studies on vitamin D deficiency and immunity, including links to influenza and COVID-19, with Public Health England advice. He walks through the sources he cites.

Dr. John Campbell reviews studies on vitamin D and immunity, including research on respiratory infections, during the early COVID-19 period.

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.

A Kurzgesagt video arguing that social media's problem is information flooding and tribal polarization. It suggests a return to smaller online communities and more in-person interaction.

Veritasium takes an IQ test and examines what IQ measures, its history including military use and eugenics, its controversies, and how it correlates with life outcomes. Experts including Cecil Reynolds and Stuart Ritchie contribute.

A doctor from Medlife Crisis explains in under three minutes why even a rich patient should not simply order every medical test, touching on pre-test probability and Bayesian reasoning. False positives make blanket testing counterproductive.

CGP Grey's quick, witty explainer on the differences between the United Kingdom, Great Britain and England, and the countries that make up the UK.

A Medlife Crisis video by cardiologist Rohin Francis on overdiagnosis and over-screening. It explains how detecting more disease does not necessarily mean saving more lives, and covers harms such as unnecessary treatment.

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.

Technology Connections explains why single-hose portable air conditioners are inefficient and often a poor choice compared with window units. It details how the single hose pulls in warm outside air and wastes energy.

Benn Jordan investigates infrasound and low-frequency noise from data centers, including xAI's Colossus and a crypto mine, and reports his own experiments on the effects. The video covers the health and community impacts on nearby residents.

America's Test Kitchen tests eight carbon-steel skillets to find the best one, asking whether a single pan can replace stainless, cast iron and nonstick. It names a winner and covers how the pans perform.

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.

CGP Grey explains what it means that a third of the United States is federally owned land. It describes the agencies that manage it and why so much of it is in the western states.

A short Globe and Mail animated explainer on why renting can leave you as well off as buying a home. It walks through a rent-versus-buy comparison using Toronto numbers and the opportunity cost of a down payment. The video notes it dates from 2015 and the housing market has changed since.

Veritasium's Derek Muller spends an hour in a silent, dark anechoic chamber at BYU to test the claim that 45 minutes is the most anyone can bear. He reports on his experience and other people's reactions.

GoldenSound publishes music on Tidal to test MQA, a deep dive into the format's claims and problems including its leaky filter. Testing begins around the 5:45 mark.

Scott Manley tells the story of a computerized telemetry system built to sit at the heart of a nuclear test device in place of the plutonium pit, designed to transmit data in the microseconds before it was destroyed.

Forgotten Weapons examines the Heckler & Koch G11, a West German experimental rifle built around a caseless cartridge. The video covers the G11K2 and its unusual technology before its cancellation for political and economic reasons.

Joseph Everett compares the food environment of the US, with roughly 30% obesity, to Japan's, around 3.5%. He argues that what is available and normal to eat explains much of the gap.

A short RepresentUs explainer arguing that US politics is shaped by money, citing the Gilens and Page Princeton study on how little average citizens influence policy.

Technology Connections explains the difference between power (watts) and energy (watt-hours) and why confusing them leads to errors. It runs about 52 minutes and uses everyday examples.

John Green explains why the US spends far more on health care than other countries, going through insurers, drug companies, hospitals and lawyers. He argues the causes are complicated rather than a simple blame game.

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.

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.

Freya Holmer explains how Bezier curves work, from the helper-line construction to their uses in animation, text rendering and shapes. It uses visuals from her Unity Shapes plugin and was a SoME1 contest winner.

Techmoan's beginner introduction to the compact cassette, testing metal tapes and Dolby S noise reduction on a Sony TC-S1 deck. He checks whether a cassette can sound close to a CD when good tape and equipment are used.

Kurzgesagt compares how many people nuclear accidents have killed against other energy sources. It walks through the worst nuclear accidents and puts their death tolls in context per unit of energy.

Technology Connections explains that the so-called EV charger in an electric car's charging cable or wall unit is really an EVSE, a smart switch that safely delivers AC power. The actual charger is inside the car. The video covers the safety signaling and mechanisms involved.

CGP Grey explains why "Indian" is often preferred over "Native American" in the United States, especially near reservations, and how many tribes exist in the US. He draws on conversations with people who identify as Indian.

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.

Linkus7 explains how a community reverse-engineered The Wind Waker to predict its random number generator and beat the Sploosh Kaboom battleship minigame consistently. It includes d3 animations by Peter Schmidt-Nielsen.

Mark Rober digs into bed bugs, testing popular beliefs about where they come from and how to get rid of them. It mixes entertaining experiments with research-based advice on what works and what does not.

Geoff Cumming uses a simulation to show how wildly the p value varies from one replication to the next because of sampling variability. He argues for estimation and confidence intervals over null hypothesis significance testing.

Military History Visualized charts ship production by the United States and Japan from December 1941 to September 1945. The growing numbers show why Japan, despite a stronger starting navy, could not win a long war.

Ben Eater explains why he builds computers on breadboards, including testing their signal behavior on an oscilloscope. It is a companion to his 6502 breadboard computer series.

Numberphile's James Grime discusses highly composite numbers, nicknamed anti-primes, which have more factors than any smaller number, using 5040 as the central example. It touches on Plato and Ramanujan.