Interview: Fossil Hunting, Sinkholes, and Paleobotany with Kirk Johnson | Particles of Thought

Dive into deep time to discover how fossils form, the ocean's surprising origins, and more. What do fossilized leaves, an asteroid, and Florida sinkholes have in common? Dr. Kirk Johnson oversees one of the largest natural history collections on the planet, and he has the answers. He’s spent his career digging into the story of life on Earth across millions (and billions) of years. In this episode, Hakeem and Kirk explore the science of “deep time,” how fossils actually form, and the surprising origins of Earth’s oceans. Plus, Kirk shares some hot tips on fossil hunting and how to count the number of leaves on a tree … because you never know when you might need these skills. Dr. Kirk Johnson is Sant Director at the Smithsonian Institution, National Museum of Natural History, home to one of the largest natural history collections in the world. A paleobotanist by training, his research explores ancient climates and extinct ecosystems through the study of fossil plants. He has authored more than a dozen books on paleontology and natural history and has traveled extensively in search of fossils on every continent. As a science communicator, Dr. Johnson has brought the natural world to millions through hosting acclaimed NOVA documentaries such as Polar Extremes and Making North America, blending deep scientific expertise with an engaging, accessible storytelling style. 🎧 Available on your favorite podcast platforms on August 26, 2025. Amazon Music: https://bit.ly/4msqqby Spotify: https://bit.ly/3Hz8rkI Apple Podcasts: https://apple.co/4oB3Ten If you enjoyed this podcast, please consider leaving a rating and review on Apple Podcasts. Your feedback helps new listeners find the show and allows us to continue creating great science content. Thank you for your support! https://podcasts.apple.com/us/podcast... ⭐️⭐️⭐️⭐️⭐️ 📰 Stay up to date on the latest science discoveries, full episodes, articles, videos, and more by signing up for NOVA's newsletter here: https://to.pbs.org/4brCC7Y 🛍️ Shop official NOVA 50th anniversary merch: https://nova-shop.org/ Follow on social for more NOVA content Twitter:   / novapbs   Instagram:   / novapbs   TikTok:   / novapbs   Chapters 00:00:00 Introduction 00:01:41 What is Paleobotany? 00:03:45 How Do Fossils Form? 00:10:11 The Bennu Asteroid Sample 00:18:06 Early Earth: Evolution and Extinction 00:42:02 Trees and Fossil Leaves 01:07:57 Fossil Reefs and Sinkhole Formation 01:15:23 Excavating Teen Rex 01:25:16 What Does the Future of Earth Look Like? 01:36:49 Credits "Particles of Thought" is hosted by Hakeem Oluseyi, an astrophysicist, author, STEM educator, multi-patented inventor, science journalist, TV personality, science communicator, and inspirational speaker. His research is based on "hacking stars" to understand our universe better and develop innovative new technologies. Oluseyi's work has resulted in 11 patents and more than 100 publications covering contributions to astrophysics, cosmology, and plasma physics and the development of space missions, observatories, focal plane instruments, detectors, semiconductor manufacturing, and ion propulsion. #podcast #sciencepodcast #paleontology