lock testing

CuriousMarc powers up a vintage HP 5061A cesium beam clock and explains both the quantum principle and the HP implementation in detail. It is part of a longer atomic clock series.

Practical Engineering explains how canal locks work, including the water-saving basins of the new Panama Canal locks.

A Technology Connections video essay on how analog and digital clocks shape different mental models of time, with the minute hand acting as a progress indicator.

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.

Veritasium explains why the one-way speed of light has never been measured, only the round-trip speed, since measuring it requires synchronized clocks that assume the answer. It explores the implications for relativity.

Tom Scott investigates the claim that the microwave was invented to heat hamsters, and interviews James Lovelock about freezing and microwave-thawing hamsters in the 1950s. It traces early magnetron uses beyond radar.

Benn Jordan explains how Flock Safety's license plate cameras log and share vehicle locations, and explores how adversarial AI can defeat them. It covers weak security and the surveillance risks of private police-camera networks.

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.

Sabine Hossenfelder explains how special relativity leads to the block universe, in which past, present and future all exist equally, and asks what that means for whether the past still exists.

Tom Scott explains the famous Dutch flower auction clock at Royal FloraHolland in Aalsmeer, a literal Dutch auction, and how the internet changed it. It is a short look at how the system worked then and now.

CGP Grey argues that your brain treats a whole home as one room during lockdown, blurring work, rest and leisure. He recommends creating separate spaces and routines for different activities to stay balanced.

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.

Historia Civilis traces the history of work and time discipline, comparing modern working hours with those of medieval peasants and the changes brought by clocks and industrialization. It draws on works such as Schor's The Overworked American.

Adam Savage shows a set of Mitutoyo ceramic gauge blocks and uses them to explain metrology, the science of measurement. He argues that accuracy and precision work differently than most people assume, which changes how you think about every measuring tool.

Marques Brownlee explains why iMessage's blue and green bubbles matter, covering the technical, commercial and social side of Apple's messaging lock-in. It also discusses RCS and what could be done about it.

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.

WIRED has UCLA professor Amit Sahai explain zero-knowledge proofs to a child, a teen, a college student, a grad student and an expert. Each round goes deeper into the cryptography and why it matters.

Oh The Urbanity! argues that most city dwellers live in dense residential neighbourhoods outside downtown, which can be calm and peaceful. It draws on older, denser parts of Toronto and Montreal.

Veritasium explains why bicycles are stable, arguing that gyroscopic effects are not the answer. The video shows countersteering and an experiment where riders blocked from steering the opposite way cannot turn.

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.

2swap explains how he solved the Klotski sliding-block puzzle by mapping its full state space as a graph and visualizing it. The video includes footage of the Guinness world-record solve and links to an interactive graph.

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.

Linus Tech Tips breaks down the company's income streams, including sponsors, YouTube Premium, merch and other products. It gives percentages for each revenue source.

Not Just Bikes explains why Swiss trains are considered among the best in Europe and the world, covering frequency, connections and what riding them is like.