PBS Space Time PBS Space Time

How We Know The Earth Is Ancient

Nov 3, 2026 · 22m

Summary

This episode explores the history of determining Earth's age, tracing the journey from ancient cosmogonies and Bishop Usser's biblical calculations to James Hutton's concept of deep time. The host explains how the discovery of radioactivity enabled radiometric dating, allowing scientists to accurately measure the planet's age at 4.5 billion years through methods like uranium-lead dating. The discussion also addresses listener questions about the similarities and differences between the Big Bang and white holes, as well as the nature of wormholes.

Topics discussed

Sponsor: LinkedIn Hiring Pro Sponsor: Google Chrome and Gemini Introduction: The concept of deep time Ancient cosmogonies and the idea of a beginning Bishop James Usher's calculation of 4004 BC Georges-Louis Leclerc Buffon's cooling method James Hutton and the theory of uniformitarianism Immanuel Kant's speculation on deep time and space The Copernican principle and temporal uniformitarianism Sponsor: LinkedIn Ads Sponsor: Google Chrome and Gemini Sponsor: PayPal Charles Lyell's Principles of Geology Darwin, evolution, and the geological clock Radioactivity and the heat of the Earth's interior Radiometric dating and half-lives Carbon-14 dating for organic materials Uranium-lead dating and zircon crystals Sponsor: LinkedIn Ads Sponsor: Google Chrome and Gemini Sponsor: PayPal Concordia diagrams and Arthur Holmes' estimates Dating the oldest rocks in Western Australia Lunar dating and the age of the solar system Comparison with Mayan and Hindu cosmologies Reflection on the scale of human civilization Listener comments: Big Bang vs White Holes Differences between Big Bang and White Hole singularities Einstein-Rosen bridges and Penrose diagrams Sponsor: LinkedIn Hiring Pro Sponsor: Google Chrome and Gemini Sponsor: PayPal Kerr black holes and traversing to new universes Behind the scenes: The painting and partner Bahar Fraser Cain collaboration and apartment tour request Black hole acronym jokes from listeners Sponsor: Kuvasier Cognac Sponsor: Target Holiday Gifts Sponsor: McDonald's Sausage McMuffin
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