Science Friday Folgen

Since the 1980s, Gerta Keller, professor of paleontology and geology at Princeton, has been speaking out against an idea most of us take as scientific gospel: That a giant rock from space killed the dinosaurs. Nice story, she says—but it’s just not true. Gerta's been shouted down and ostracized at conferences, but in three decades, she hasn’t backed down. And now, things might finally be coming around for Gerta’s theory. But is she right? Did something else kill the dinosaurs? Or is she just too proud to admit she’s been wrong for 30 years? Subscribe to Undiscovered HERE, or wherever you get your podcasts. GUESTS Gerta Keller, professor of paleontology and geology at Princeton James Powell, geologist and author of Night Comes to the Cretaceous: Dinosaur Extinction and the Transformation of Modern Geology (St. Martin's Press) FOOTNOTES Michael Benton reviews the many, sometimes hilarious explanations for the (non-avian) dinosaurs’ extinction. Note: Ideas marked with asterisks were jokes! More in Benton’s book. Walter Alvarez tells his own story of the impact hypothesis in T. Rex and the Crater of Doom. The New York Times interviews Luis Alvarez before he dies, and he takes some parting shots at his scientific opponents. The impact and the Cretaceous-Tertiary boundary were simultaneous according to this paper. Learn more about how volcanoes are major suspects in mass extinctions. Read more about Gerta Keller, the holdout. CREDITS This episode of Undiscovered was reported and produced by Elah Feder and Annie Minoff. Our senior editor is Christopher Intagliata. Original music by Daniel Peterschmidt. Fact-checking help from Robin Palmer. Lucy Huang polled visitors to AMNH about what killed the dinosaurs. Our theme music is by I Am Robot And Proud. Excerpts from All Things Considered used with permission from NPR. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Climate change is increasing temperatures and causing heavier rainfalls across the country. Scientists are studying how these changes will affect different natural resources, including the soil ecosystem. For example, in Wisconsin, soil erosion is predicted to double by 2050 due to heavier rainfalls, according to a report by the Wisconsin Initiative on Climate Change Impacts. Agricultural scientist Andrea Basche talks about how soil formation and health is tied to climate. She joins microbiologist Kristen DeAngelis, who is conducting a long-term study to determine how increased temperatures affect soil microbiome, how to protect this resource, and what our soil reserves might look like in the next fifty years. Plants have a unique challenge in staying alive long enough to produce offspring. Unable to move and at the mercy of their surroundings, they present a tempting source of nutrition for bacteria and animals alike. But they’re not helpless. Botanists have long known plants are capable of sensing their environments and responding to them. They can grow differently in response to shade or drought, or release noxious chemicals to fend off predators, even as a caterpillar is mid-way through chewing on a leaf. But how does that information travel? New research published in the journal Science shows a first glimpse, in real time, of distress signals traveling from one leaf, snipped, crushed, or chewed, to other healthy leaves in the same plant. The signal, a wave of calcium ions, seems linked to the amino acid glutamate, which in animals acts as a neurotransmitter. University of Wisconsin-Madison botany professor Simon Gilroy, a co-author on the new research, explains this chemical signaling pathway and other advances in how we understand plant communication.  At some science fairs, baking soda volcanos can grab the blue ribbon prize. But at the International Science and Engineering Fair (ISEF), a winning project is a design to kill cancer cells. ISEF is the grand championship of science fairs, where students from around the world submit their best research projects and compete in a high-stakes, hormone-filled challenge, which is showcased in full display in the new film, Science Fair. Like any high school experience, it can be a pressure cooker of anxiety, but also a time when many students find their calling—a crucible from which our future scientists are born. Ira talks with one of the film’s directors, Cristina Costantini, and catches up with a former ISEF participant Robbie Barrat, to discuss life after Science Fair. View a trailer of the film below and find screening times and locations here. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Last month, California passed a bill ending the use of cash bail. Instead of waiting in jail or putting down a cash deposit to await trial at home, defendants are released after the pleadings. The catch? Not everyone gets this treatment. It’s not a judge who determines who should and shouldn’t be released; it’s an algorithm. Algorithms have also been used to figure out which incarcerated individuals should be released on parole. Mathematician Hannah Fry and computer scientist Suresh Venkatasubramanian join Ira to discuss how algorithms are being used not only in the justice system, but in healthcare and data mining too.  As Hurricane Florence approaches the Carolinas this week, forecasters and disaster management officials are stressing one key piece of advice to evacuating residents: Take the storm seriously, regardless of the category designation. Once projected to hit Category 4, Florence was at Category 2 as of Thursday morning, but that number only describes the wind speed. Meanwhile, as University of California-Irvine civil engineer Amir AghaKouchak notes, there could be unusually devastating flooding, as storm surge from the ocean meets rainfall from a storm that is projected to pour on the region for days. “Compound flooding” is the phenomenon that left Houston under water after Hurricane Harvey in 2017, and, at its worse, could cause rivers to run in reverse. And, AghaKouchak says, climate change and sea level rise both make such flooding more likely in storms like Florence. The prevailing theory says a meteorite led to the demise of the dinos. But Gerta Keller, a longtime geologist and paleontologist, isn’t buying it, and says volcanoes were the real culprit. The latest episode of Undiscovered tells her story, and asks whether conflict among scientists really makes science stronger. Co-hosts Elah Feder and Annie Minoff join Ira for a preview. Subscribe to Undiscovered wherever you get your podcasts.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.