A paleontologist estimates that a dinosaur species lived 150 million years ago. If the half-life of a radioactive isotope used for dating is 50 million years, how many half-lives have passed since the species went extinct?

Sun, 03 May 2026 20:37:04 +0000

**How Many Half-Lives Have Passed When a Dinosaur Species Lived 150 Million Years Ago?**
*Supported by a paleontologist’s use of radioactive dating and half-life calculations — Why this science matters in 2025* A paleontologist estimates that a dinosaur species lived 150 million years ago — a moment etched in Earth’s deep history. Advances in radiometric dating now allow scientists to refine timelines of extinction and evolution, often relying on isotopes with known half-lives. When a fossilized species is traced to 150 million years ago and the half-life of a key isotope used in dating is 50 million years, many wonder: how many half-lives have passed since that species vanished? Understanding this number offers a tangible way to grasp the vastness of prehistory — and the precision of modern science. It’s not just a number; it’s a bridge between ancient life and measurable time. ### Why This Calculation Is Gaining Momentum in the US