@wy7usa Mark Rober does a much more thorough job: https://www.youtube.com/watch?v=xoxhDk-hwuo&list=PLgeXOVaJo_gnexNopBzUKdl3QKoADJlS8
QOTO: Question Others to Teach Ourselves An inclusive, Academic Freedom, instance All cultures welcome. Hate speech and harassment strictly forbidden.