fm radio

Technology Connections explains why the superheterodyne radio has its name and how mixing frequencies lets it tune stations well. It walks through the underlying wave phenomena and algebra and why the design solved a hard tuning problem.

The Thought Emporium tests so-called negative ion and anti-5G wellness products and finds they are radioactive, with some coated in powdered thorium.

Veritasium visits Chernobyl, Fukushima and other places to find who on Earth is exposed to the most ionizing radiation. The answer turns out to be surprising and puts radiation risk in context.

James Hoffmann explains how decaf coffee is made, how the decaffeination processes differ, and why decaf is roasted and stales differently. He also discusses decaf quality and health questions.

The Thought Emporium follows up on his earlier video showing negative ion products are radioactive, reporting that Amazon pulled listings and companies shut down. He tests more radioactive quack products with a Geiger counter and cloud chamber.

A PBS clip in which Richard Feynman explains the strange nature of light and electromagnetic radiation. He conveys how little of it we actually see and how radio waves are present everywhere.

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.

FortNine argues that the US DOT motorcycle helmet standard (FMVSS 218) is badly outdated and weak.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.

James Hoffmann runs caffeine analyzer tests comparing filter versus espresso, extraction over time, steep time, instant coffee and light versus dark roast.

Veritasium explains how cosmic rays and other particles flip bits in computer memory, with examples including a Belgian election count error, plane incidents and game glitches. It is inspired by a RadioLab episode on bit flips.

A 105-minute technical deep dive from Noise In Space evaluating whether Starlink satellites could work as synthetic aperture radar. It covers SAR signal-to-noise, amplifiers, antennas, duplexing, phased array beamforming and simulations of V2 Mini and V3 satellites.