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A short promotional video demonstrating a head-thumping technique that is claimed to relieve tinnitus. Covering the ears and tapping the back of the head is said to silence the ringing temporarily.

A University of Michigan Medicine demonstration of building a cheap DIY air purifier from a box fan and a HEPA or high-MERV filter using hardware-store parts. It explains why this helps against dust, smoke and viruses and ties it to local air quality readings.

Anders Brownworth gives a basic visual introduction to blockchain using an interactive web demo, covering SHA256 hashes, blocks, chains, distribution, tokens and coinbase transactions.

Jacques Pepin demonstrates deboning a whole chicken, quickly and with complete control. It is a short, wordless-feeling technique demo that shows a skill most cooks never learn.

Shawn Hymel of DigiKey introduces KiCad and explains how printed circuit boards are manufactured. It is the first part of a beginner series that builds a 555 badge project.

The Townsends channel shows how to make mushroom ketchup, a popular 18th-century sauce, in period style. It includes the history and a recipe and links to a blog post on whether George Washington used ketchup.

Mathologer shows a simple idea, the commutator, that lets anyone who can solve the first layer design their own full Rubik's cube solution. The same idea carries over to other symmetric twisty puzzles such as the Megaminx.

ChefSteps shows how to make espresso-style coffee in a moka pot, with a bonus latte hack. It is a quick how-to aimed at home brewers.

Dodoid gives an in-depth look at an SGI Onyx RealityEngine2, a $250,000 graphics supercomputer from 1993, covering its history, a physical overview, a teardown and some demos and games.