A survey of the Earth's history through the lens of the geologic timescale. We begin with a discussion of the terminology of geochronologic units and how they are specified using 'golden spikes'. We then review the development of Earth's atmosphere, geosphere, and biosphere through the Hadean, Archean, Proterozoic, and Phanerozoic eons. We cover many topics including the supercontinent cycle, the great oxidation event, the evolution of eukaryotes, the Cambrian explosion, and mass extinctions. Recommended pre-listening is Episode 156: Fossils and Dating Methods. If you enjoyed the podcast please consider supporting the show by making a PayPal donation or becoming a Patreon supporter. https://www.patreon.com/jamesfodor https://www.paypal.me/ScienceofEverything