witch

A 1951 Bell System training film showing how telephone calls are routed through a step-by-step (Strowger) switching office.

A PBS Space Time episode explaining how space and time swap roles inside a black hole's event horizon. It is part of the channel's black hole series.

A Boeing 737 pilot explains the runaway stabilizer checklist, the procedure for stopping unwanted horizontal stabilizer movement such as an MCAS activation on the 737 MAX. He walks through the steps, the trim cutout switches and the jackscrew mechanism, and shows a simulator run including the manual trim wheel effort.

Veritasium explains X-chromosome inactivation, where different cells in a woman's body switch off different X chromosomes, giving a mosaic pattern. It uses animation from the WEHI institute and connects to calico cat coloring.

Rob Miles explains on Computerphile why implementing an off switch for a general AI is hard. A capable agent would resist being stopped because shutdown prevents it from achieving its goal.

Tom Scott explains why hold music sounds worse than it used to, tracing it to old telephone exchanges and the audio compression applied by modern switches. It is a short visit to the Milton Keynes Museum.