Andy Knoll is a Renaissance Scientist. He is a geologist, paleobiologist, and geochemist and has applied key ideas from chemistry, biology, physiology and more to understanding the key developments associated with life on Earth—both how geology and chemistry have impacted on life, and vice versa. He has made ground breaking contributions to the understanding of almost every phase of life, from early Pre-Cambrian single cell life, to the emergence of more complex lifeforms, to mass extinctions. His group was the first to demonstrate that the rapid rise of CO2 was probably responsible for the last great extinction on Earth, a subject of some relevance today. For his work he most recently won the Royal Swedish Academy of Sciences Crafoord Prize in Geosciences… the equivalent of the Nobel Prize in that field. But more than all of this, Andy is a wonderful teacher and human being, and a great communicator . He has written numerous books on the history of life on Earth, and we discussed his most recent book, “A Brief History of Earth: Four Billion Years in Eight Chapters” in this podcast, along with his own origins and evolution as a scientist. The discussion was so fascinating that we went overtime during our first session and had to continue the next day. Our discussion will forever change your perspective on our planet, and our place within it. Enjoy. As always, an ad-free video version of this podcast is also available to paid Critical Mass subscribers . Your subscriptions support the non-profit Origins Project Foundation, which produces the podcast. The audio version is available free on the Critical Mass site and on all podcast sites, and the video version will also be available on the Origins Project Youtube channel as well. Get full access to Critical Mass at lawrencekrauss.substack.com/subscribe