Gen-X professor burnout. The videos are from online courses I made with Rice Online for edX and Coursera. Here are links to the full courses if you are interested.
https://www.coursera.org/specializations/introduction-to-mechanics
https://www.coursera.org/specializations/introduction-to-electricity-magnetism
https://www.coursera.org/specializations/waves-optics

The short videos are a "relatively new endeavor".
https://linktr.ee/ProfessorHafner