Education has traditionally gone from teacher to student. This is partly a leftover from the age when the university was a vault of information not available elsewhere. Teachers were truly walking repositories of knowledge. But all that has changed. Now, nearly everything I teach is available elsewhere. More important, information can be preserved digitally. This means that students can become teachers by producing permanent course content for other students. This also means that students can produce course content for future classes, engaging in a conversation across generations of learners.