Did Gravity Wipe Out The Dinosaurs?

A provocative new theory suggests that a sudden change in the strength of gravity—just before humanity began measuring the universe—might have triggered the asteroid impact that wiped out the dinosaurs. This idea, explored in a recent article by physicist Chris Lintert, ties into the long-standing 'Hubble tension'—the discrepancy in measurements of the universe's expansion rate. The hypothesis posits that if gravity strengthened by 10% around 66 million years ago, it could have destabilized orbits in the outer solar system, flinging a massive asteroid toward Earth. While the idea is tantalizingly convenient—coinciding with both the dinosaur extinction and the dawn of modern cosmology—it remains highly speculative. Experts stress that gravity’s fundamental constant (G) is assumed to be unchanging, and no evidence supports its variation over time or space. Still, the theory opens a fascinating door to questioning whether gravity itself might be more dynamic than we think. The episode also dives into whimsical listener questions—from naming exoplanets after Douglas Adams characters to reusing ISS modules for lunar construction—highlighting the joy of curiosity in science. The discussion underscores that while some ideas are too elegant to be true, they’re still valuable: they challenge assumptions, inspire new research, and remind us that science thrives on the unexpected.