Radical Physics (RP) is an online presentation of introductory physics. "Radical," here, means "root-like": probing some of the deepest and worthiest ideas in this most fundamental science.
Besides the masthead quotation, UC Berkeley's Alex Filippenko says of RP: "These short videos are a fine supplement to high school or basic college physics courses. They offer an excellent introduction to many important concepts in physics."
So-called "taproot" RP episodes present the most essential ideas from an introductory physics course; they are labeled with the code RPn, where n is a counting number. "Tendril" episodes present secondary ideas that sprout from corresponding taproot episodes; they are labeled with the code RPnx, where x is a lowercase letter. For example, "RP4a" indicates the first tendril of the fourth taproot episode.
RP is produced by Wonderfest, the nonprofit San Francisco Bay Area Beacon of Science.