So who cares? We should care. Kuhn's work supports the idea that science progresses from-what-we-know to what-we-know-next. This is in contrast with the Whig interpretation of science, which is the inevitable march from darkness to light, from confusion to clarity, from error to truth. Of course, there is nothing wrong with teaching physics by recounting its past successes, but that is not in fact how the dynamic of knowledge works.