explanation

A motorcycle safety video on the SMIDSY (sorry mate, I didn't see you) accident, explaining the perception and optical illusion that makes drivers fail to see riders, and how riders can spot the signs and avoid it.

A beginner-focused tutorial on freehand knife sharpening with a single stone, aiming for a shaving-sharp edge in about five minutes.

An episode of FunFunFunction explaining monads in JavaScript as functors that also implement flatMap. It builds on the preceding functor episode and works through code examples.

ElectroBOOM's Mehdi Sadaghdar explains how a full bridge rectifier works, the building block of AC to DC converters, with his usual humor and a demonstration of the circuit.

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.

Ben Eater shows how to build logic gates out of transistors, including NOR gates. It is part of his clear hardware-from-scratch teaching style.

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.

Big Clive shows how to pick up discarded disposable vape devices from the roadside and extract the rechargeable lithium cells inside. He explains why these devices contain the same circuitry as rechargeable ones and how to reuse the cells.

CuriousMarc inspects a newly arrived Teletype Model 19, an early military unit built around a Model 15 keyboard and printer, after an initial rough cleaning. It is the first part of a restoration series and touches on 5-bit Baudot code.

Wim Hof guides viewers step by step through his breathing method, with some explanation of the science he cites behind it. It stresses learning from the source and avoiding unsafe settings.

A step-by-step guide to building a lifter, a small triangular ionocraft made from balsa wood, aluminum foil and thin wire, powered by a high-voltage supply. It also shows high-voltage safety practices.

The Original Ace shows how creators can use a third-party music distributor to file Content ID claims on their own videos, turning false-claim abuse into a share of ad revenue. It also names distribution companies and their revenue splits.