Gethyn Jones has been a teacher of physics for thirty years. He has worked in a number of state schools and academies in England and Wales and has over twenty four years experience as Head of Physics. He currently teaches at an independent school in London. He has written the emc2andallthat blog (https://physicsteacher.blog/) on a range of physics education related issues for the last eight years and tweets as @emc2andallthat. He has been a member of the Ofsted Science working party for the last two years. Gethyn Jones contributed a chapter to the recent 'ResearchED Guide Explicit and Direct Instruction' (2019). 'Cracking Key Concepts in Secondary Science' (co-authored with Adam Boxer and Heena Dave) is his first book.