This paper examines the cross fertilisation of ideas about interactive teaching from law to physics and back again. In particular it considers the origin, legacy and merits of Langdell’s teaching model and the way it has been used by a physics professor, Eric Mazur, to support arguments for what is commonly known as the ‘flipped classroom’. It examines the similarities and differences between Langdell’s and Mazur’s approaches and the adoption by some law teachers of Mazur’s model. It also considers how this phenomenon bares out a thesis advanced by educationalist Lee Shulman that when it comes to teaching, both professional and liberal disciplines are pursuing many of the same ends. Finally it considers the implications of adopting Mazur’s approach for the discipline of law and issues some words of caution.