Science Friday Folgen

Maple tapping season is underway in the sugar maple stands of the United States. Warm days and below-freezing nights kick off a cycle of sap flow crucial for maple syrup production. But why is the flow of sap so temperature dependent in sugar maples? University of Vermont maple researcher Abby van den Berg explains how ice crystals in the trees’ cells power sap flow, while Yale University’s Craig Brodersen tackles how other trees and plants move gallons of fluid per day from roots to leaves—all without using any energy at all. In mid-March, a late winter storm dumped inches of rain on frozen soil in the Midwest, flooding the Missouri River and tributaries—particularly in agriculture-intensive Iowa, eastern Nebraska, and western Illinois. The storm has submerged farm fields under water, washed-out roads and bridges, caused grain silos to burst from flood damage, and drowned livestock. Many farmers may be unable to plant their fields in time this year, or even at all. But soil experts looking at that same damage will notice another thing: erosion of precious topsoil. This first layer of soil is the key to the Midwest’s immense fertility and agricultural strength, but a resource that is slow to rebuild after major losses like farms are currently experiencing. Mahdi Al-Kaisi, a soil scientist at Iowa State University, explains why erosion is bad news for farmers, and how the damage from this flood event could ripple for years to come. Bristlecone pine trees grow in harsh, dry mountain climates and can live up to 5,000 years old. The trees have adapted to these rough habitats by building up dense woody trunks that can hold up against insects, and rely on the wind to disperse their hard seeds. Ecologist Brian Smithers became interested in these species because “they epitomized growing and living on the edge of what is possible.” Smithers talks about the adaptations and competition the species will face as rising temperatures from climate change force the trees to move up in elevation. Washington University’s analysis of data from Missouri utility companies shows high levels of toxic coal ash contamination near ponds power plants use to dump waste from coal combustion. Will proposed new regulations be enough?   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

April is National Poetry Month, a time of readings, outreach programs, and enthusiastic celebration of the craft. And for a special Science Friday celebration, we’ll be looking at where science and poetry meet. Tracy K. Smith, the current U.S. poet laureate, wrote the 2011 book Life On Mars, which touches on dark matter, the nature of the universe, and the Hubble Telescope—all as an elegy for her deceased engineer father, Floyd. Rafael Campo, a physician, poet, and editor for the Journal of the American Medical Association’s poetry section, writes poems about illness, the body, and the narratives each patient brings to medical settings. The two talk to Ira about where science fits into their work—and how poetry can inform science and scientists. Read some of the poems, and a syllabus of science-related works suggested by SciFri listeners, here. Calculus underpins many of the greatest ideas about how the universe works: Newton's Laws, Maxwell's Equations, quantum theory. It's been used to develop ubiquitous technologies, like GPS. It was even used to model the battle between HIV and the human immune system, which helped researchers fine tune triple-drug therapies to combat the virus. In his book Infinite Powers: How Calculus Reveals the Secrets of the Universe, mathematician Steven Strogatz takes readers on a journey around the world, detailing the bright ideas that contributed to modern calculus and citing the many ways those mathematical ideas have changed the world. Learn more here. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Once upon a time, everything in the universe was crammed into a very small space. Then came the Big Bang, and the universe has been expanding ever since. But just how fast is it expanding? Calculating that number is a challenge that dates back almost a hundred years, when Edwin Hubble used data from Harvard astronomer Henrietta Swan Leavitt to try to answer that question. His value came to be called the Hubble constant, H0. But the exact value of that constant has been hard to pin down. And now two different approaches to measuring the Hubble constant have come up with close, but different answers—and each team says they're pretty confident in the accuracy of their measurements. Ira speaks to science writer and author Anil Ananthaswamy and Nobel laureate Adam Riess to discuss the discrepancy. This flu season, Science Friday teamed up with Flu Near You to ask listeners to track their symptoms to create a map of influenza-like illness across the country. Nearly three thousand SciFri users participated. Science Friday education director Ariel Zych and biostatician Kristin Baltrusaitis, who was a research assistant for Flu Near You, tells us how the SciFri community results stacked up to the rest of participants. Plus, epidemiologist Karen Martin gives an update on how this season compares to years past and how the Minnesota Department of Health uses Flu Near You data for surveillance on a local level. See the results here. It’s become the familiar refrain in this era of climate change: Warmer temperatures, retreating glaciers, and rising sea levels. But when it comes to Greenland’s Jakobshavn Glacier, it seems the drumbeat of disaster may have halted—for now. Scientists report in the journal Nature Geoscience this week that the once fast-retreating ice sheet has been thickening over the last few years instead. It’s a reversal of a twenty-year trend of thinning and retreating, but perhaps not for long. Ala Khazendar, researcher at NASA’s Jet Propulsion Laboratory, joins Ira to explain why this glacial about-face may not be the cause for celebration that we think it is in this week’s Good Thing, Bad Thing. And Gizmodo writer Ryan Mandelbaum talks about the canceled all-female space walk, NASA's lunar ambitions, and more in this week's News Roundup.   Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.