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.

3Blue1Brown explains the math and mechanics behind Bitcoin visually: ledgers, digital signatures, proof of work and the blockchain, building up a decentralized payment system from first principles.

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.

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.

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.

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.

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.

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.