Teaching by night and reflecting on a subject by day is the way that Salman Khan sees education evolving in the age of online lectures. Khan believes he is onto something in what he styles the "flipped classroom." In Khan's view, there is no need for students to be divided into grades by age. Instead, they should learn at their own pace, moving on to the next lesson only when they have mastered the concept before it. Students watch videos that introduce the concepts at home and then go to class to demonstrate their learning. There would be no need for a teacher to stand in front of the class and give a lecture ever again. In the flipped classroom, the teacher shifts from being the "sage on the stage to the guide on the side." Lecture material is covered at home so that activities traditionally associated with homework such as math problems, history essays, and science projects, become activities in the classroom with personalized attention. The Khan Academy is good in that it helps students do their homework and may even help them pass end-of-year tests. It is a wonderful resource for people looking to acquire basic skills. Whether the Khan approach becomes a real or failed revolution will soon be evident. In any event, the intense interest in the flipped classroom is good for education.