Science Friday Folgen

Flame Retardant Could Be Made From Discarded Cocoa HusksOn cocoa farms around the world, cocoa beans are pulled from their pods, and the hard husks are discarded, leaving 20 million tons of plant waste to biodegrade and potentially harm future crops. These husks are a source of lignin, a substance that gives plants their rigidity. It’s extremely abundant—but often wasted.A new study published in the journal ACS Sustainable Chemistry and Engineering found that the lignin processed from leftover cocoa pod husks could have a new use as an ingredient in flame retardant.“Lignin is pretty special, as it is very soluble in organic solvents,” said study co-author Dr. Nicholas Westwood, a professor of chemistry and chemical biology at St. Andrews University in Scotland, in an email. This means lignin can be chemically manipulated to create a number of useful substances relatively easily.Because of lignin’s malleability, Westwood and his coauthors were able to add a flame-retardant molecule to the processed substance, and found that the modification increased its already naturally high ability to smother flames.That’s just one possible application. While lignin hasn’t found widespread industrial use yet, scientists hold hope for it to become a greener alternative for fuel and a biodegradable plastic instead of just being leftovers. Processing biomass for food or fuel also produces a massive amount of lignin as a byproduct, which has been converted to materials like activated charcoal or carbon foam. “There are endless possibilities,” Westwood said.​​Joining Ira to talk about lignin and its potential uses is Dr. Rigoberto Advincula, a materials scientist with the Oak Ridge National Laboratory and the University of Tennessee in Knoxville.The Oozy Physics Of OobleckYou may be familiar with a common science demonstration done in classrooms: If you mix cornstarch and water together in the right proportions, you create a gooey material that seems to defy the rules of physics. It flows like a liquid, but when you try to handle it quickly, it stiffens up.This kind of material is called an oobleck, and it’s a type of non-Newtonian fluid, meaning its viscosity changes under pressure or stress. Oobleck-like materials include human-made things like Silly Putty and paint, but are also found in nature; blood and quicksand are both non-Newtonian fluids.For a long time, it’s been hard to prove exactly why these materials act the way they do. But recently, scientists developed a better understanding of the underlying physics. A new study conducted in collaboration between the James Franck Institute and Pritzker School of Molecular Engineering at the University of Chicago was able to demonstrate this mechanism.“The findings from this study are important because they provide direct experimental evidence for one of the mechanisms proposed for strong shear thickening,” says Dr. Heinrich Jaeger, professor of physics at the University of Chicago. “Namely, frictional interactions as the particles in the liquid are sheared into contact.” Jaeger is a co-author of the study, which was led by postdoctoral researcher Dr. Hojin Kim.Jaeger and Kim speculate that a better understanding of non-Newtonian fluids could help in the development of new, advanced materials. The potential ranges from flexible speed bumps to impact-resistant clothing. Jaeger joins Ira to talk about it.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Follow our show on Instagram, TikTok, Facebook, and Bluesky @scifri and sign up for our newsletters. Got a science question that’s keeping you up at night? Call us: 877-472-4374 Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Between supplying fuel to military bases, planes, and ships, making and using weapons, and clearing land, militaries around the world account for almost 6% of global greenhouse gas emissions.A new report calculated how much the militaries of the United States and the United Kingdom would hypothetically “owe” if they paid for the damage caused by their carbon emissions. The total came up to $111 billion. So what can the military do about its emissions? And what does militarism in the context of the climate crisis look like?Ira talks with two of the report’s authors, Khem Rogaly, a senior researcher at London-based think tank Common Wealth, and Dr. Patrick Bigger, research director at the Climate and Community Project, a progressive climate policy think tank in the US.Transcripts for each segment will be available the week after the show airs on sciencefriday.com. Subscribe to this podcast. Follow our show on Instagram, TikTok, Facebook, and Bluesky @scifri and sign up for our newsletters. Got a science question that’s keeping you up at night? Call us: 877-472-4374 Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Scientists Report Second Highest-Energy Cosmic Ray Ever DetectedAround 30 years ago, scientists in Utah were monitoring the skies for cosmic rays when they detected a surprising particle. It struck the atmosphere with much more energy than they had previously seen—enough energy to cause the researchers to dub it the “Oh My God Particle.”Over the years, a collaboration of researchers in Utah and Japan has detected other powerful rays—about 30 a year—but none that rival the OMG. In 2021, however, a second particle was detected. It was only slightly less powerful than OMG, but still many times more powerful than can be created on Earth. That 2021 particle was named “Amaterasu,” after a sun goddess from the Japanese Shinto religion. The researchers described their observations in a recent issue of the journal Science.The researchers believe the particle must have come from relatively nearby, cosmically speaking, as otherwise it would likely have collided with something in space and lost its energy. However, when they tried to trace the particle back to its origin in space, they were unsuccessful. Both the OMG particle and the new Amaterasu particle seem to have come from empty regions of space, with no violent events or massive structures to create them.Dr. John Matthews, a research professor in physics and astronomy and manager of the Cosmic Ray Physics Program at the University of Utah, joins Ira to talk about cosmic rays, how they’re detected, and the challenges of finding the origin of particles like Amaterasu.These Penguins Are The Masters Of MicrosleepingDo you know that feeling when you’re just so tired that your head starts to droop? Your eyes feel heavy? And you drift off for just a moment … before snapping back to alertness, wondering what just happened.Sleep comes in a variety of snoozes and sizes. We humans are not going to get a full night’s rest by nodding off here and there, but that’s pretty much what some chinstrap penguins do: They doze off more than 10,000 times a day, for just a few seconds at a time. And when you do the math, it can add up to 11 hours of sleep each day, according to a recent study in the journal Science.Ira talks with study author Dr. Paul-Antoine Libourel, a sleep biologist at the Neurosciences Research Center of Lyon in France, about how the penguins do this and the advantages of microsleeps.Transcripts for each segment will be available the week after the show airs on sciencefriday.com. Subscribe to this podcast. Follow our show on Instagram, TikTok, Facebook, and Bluesky @scifri and sign up for our newsletters. Got a science question that’s keeping you up at night? Call us: 877-472-4374 Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.