reactive programming

A SciShow episode in which Hank Green introduces five of the most dangerous chemicals, from lethal toxins to substances that explode on contact. It is an entertaining overview of extreme chemical hazards.

Tom Scott explains for Computerphile why handling time and timezones in code is so hard, walking through a simple web app that computes how long ago something happened. It covers the quirks of timezones and calendars and ends in an exasperated rant.