shift happens

I had to use the title of the article I'm linking to; it was just too good. The article is a summary and celebration of the mind-expanding book by Thomas Kuhn, The Structure of Scientific Revolutions, published 50 years ago.  I've assigned the book in various courses over the years, including ones on military innovation and international relations theory, because it has a powerful message about how hard it is for people to change their minds, even in the supposedly empirical natural sciences. Kuhn developed the concept of a "paradigm shift" [hence the cute headline] and showed that in the history of the natural sciences it wasn't the result of changed minds but rather a change in which schools of thought came to dominate the field. If you're not going to read the original, at least look at this discussion of it.