The YouTube channel MinutePhysics offers a new video every week, each about 90 seconds (OK, more than a minute) on topics such as: What is Fire?, Distance and Special Relativity, What is a Dimension?, Adding Past Infinity. They’re fast-paced, entertaining, and thought-provoking — similar to the math/music videos by the multi-talented Vi Hart. Vi Hart’s Math Doodling videos carry a motif of “I’m bored in class, and this is so much cooler,” which makes them less useful for classrooms.  But her others, including her latest video, What is up with Noises? (The Science and Mathematics of Sound, Frequency, and Pitch) present information and arguments in a challenging and entertaining way.