“Explained” (Netflix): A series of short video essays on topics ranging from the world’s water crisis to the gender wage gap to cricket. These 20-minute documentaries are neither comprehensive nor entirely convincing, but they address interesting problems (e.g., Cape Town and Mexico City are two of a dozen major cities that are on the verge of running out of water) and provide provocative facts (e.g., 130 liters of water are needed to produce the beans for one cup of coffee).