Particles of Thought

What does it feel like to make one of the biggest discoveries in physics? Adam Riess knows — because his work revealed that the universe isn’t just expanding, it’s accelerating. In this episode, the Nobel Prize–winning astrophysicist takes us behind the scenes of the moment that changed cosmology forever. How did his team use exploding stars as “standard candles” to measure the cosmos? Why did the data point to a mysterious force now called dark energy, making up nearly 70% of the universe? And what’s behind today’s biggest cosmic puzzle: the Hubble tension? Plus, Adam shares what new telescopes could uncover — and why the next decade might rewrite the laws of physics all over again. Learn more about NOVA and subscribe to our YouTube channel. —————————Guest Bio: Adam Riess is an astrophysicist, professor at Johns Hopkins University, and a distinguished astronomer at Space Telescope Science Institute. In 2011, he was named as a co-winner of the Nobel Prize in Physics for his contributions to the discovery that the expansion rate of the universe is accelerating. Since then, he has continued refining measurements of cosmic expansion and the Hubble constant, aiming to find and measure the most distant type Ia supernovae known, to probe the origin of cosmic acceleration.Timestamps(00:00:00) Introduction(00:03:16) What Is a Type Ia Supernova? (00:10:52) The Discovery of Dark Energy(00:44:39) What Is the Hubble Tension?(00:58:59) Winning a Nobel Prize(01:15:32) Credits

The universe isn’t adding up—and it’s creating a crisis in cosmology. Nobel Prize winner Adam Riess explains why measurements of the universe’s expansion rate from its earliest light and from nearby galaxies don’t match, and how this growing gap threatens the foundations of our standard model of the cosmos.For more, check out the extended interview with Adam RiessLearn more about NOVA and subscribe to our YouTube channel. 

Discovering dark energy wasn’t just thrilling—it was terrifying. Nobel Prize Winner Adam Riess explains the nerve-wracking process behind confirming that the universe’s expansion is accelerating and why Einstein’s so-called “biggest blunder” turned out to be anything but.For more, check out the extended interview with Adam RiessLearn more about NOVA and subscribe to our YouTube channel. 

Fame can hijack the brain like a drug—activating the same reward circuits that fuel a relentless chase for dopamine highs. Neuroscientist Heather Berlin reveals the antidote—and why even social media fame can trigger this cycle.For more, check out the extended interview with Heather Berlin.Learn more about NOVA and subscribe to our YouTube channel. 

Fossilization isn’t luck - it’s geology. Paleobotanist Kirk Johnson explains how fossils only form in certain conditions, the tricks to finding them, and why one fossil leaf can lead to thousands more. For more, check out the extended interview with Kirk Johnson.Learn more about NOVA and subscribe to our YouTube channel.