The focus of this episode is Massimo's new book, Nonsense on Stilts: How to Tell Science from Bunk. The book, broadly speaking, is about what philosopher Karl Popper famously called the demarcation problem: how do we tell the difference among science, non-science and pseudoscience? We explore the complex relationship among these, ranging from solid science like fundamental physics and evolutionary biology to definite pseudosciences like astrology and creationism. In the middle are the more interesting borderline areas that include the search for extraterrestrial intelligence, evolutionary psychology, and even superstring theory, to name but a few.

We also discuss other topics covered in the book, including the whole issue of expertise and Think Tanks, which plays such an important role especially in media presentations of issues such as evolution, climate change, HIV-AIDS, or the alleged connection between vaccines and autism. Julia and Massimo also address the ultimate question about pseudoscience: why do we care?