Astronomy Cast Ep. 749: Dark Energy Changing Over Time By Fraser Cain & Dr. Pamela Gay Streamed live on Mar 24, 2025. The Hubble Tension is a vexing problem, with astronomers measuring the expansion of the Universe at different points in its history and getting different results. Errors have mostly been ruled out, which leaves the potential for new physics. Has the strength of dark energy been changing over time? We thought Dark Energy was constant with time, but new results from DESI say maybe not, and honestly, if it wasn't constant the Hubble Tension would be a whole lot easier to solve.   SUPPORTED BY YOU! This Episode is made possible thanks to our Patrons on Patreon. Join at the Galaxy Group level or higher to be listed in our YouTube videos.  Thanks to: BogieNet, Stephen Vei, Jeanette Wink, Siggi Kemmler, Andrew Poelstra, Brian Cagle, David Truog, Ed, David, Gerhard Schwarzer, Sergio Sancevero, Sergey Manouilov, Burry Gowen, David Rossetter, Michael Purcell, Jason Kwong