zero-knowledge

Part one of a 1996 BBC Modern Times documentary on the training to become a London black cab driver. It follows candidates learning the Knowledge and facing stressful repeated exams with Public Carriage Office examiners.

Motherboard's 2014 visit to a secretive Bitcoin mining operation in a repurposed factory in Liaoning, China, one of six sites producing about 4,050 bitcoins a month. It shows the machines and the workers' living conditions.