The Science of Saliva

A Dying Planet Offers A Peek Into The Future

This week, astronomers reported in the journal Nature that they had spotted a planet approximately the size of Jupiter being swallowed by a star over the course of ten days. The star, called ZTF SLRN-2020, is about 15,000 light-years away from our solar system, but still in our own galaxy. Astronomers had thought this type of planet-engulfing must happen, based on how stars evolve and certain chemical signatures they’ve spotted from inside stars. However, this is the first time the process has actually been observed. Our own sun is predicted to go through a similar expansion in about five billion years, consuming Mercury, Venus, and likely Earth.

Tim Revell, deputy US editor at New Scientist, joins Ira to talk about the fate of the planet and other stories from the week in science, including mapping the trees of Africa, an experimental Alzheimer’s drug showing early promise, and reconstructing a short movie clip based on brain signals recorded in mice.

How good are you at tasting what you eat? Not just gulping food down, but actually savoring the flavor? When you think about how taste works, you may think about your tongue and taste buds, and how they send information about your food info to your brain. But there’s an overlooked—and understudied—hero in this story: saliva. That may sound strange, since part of saliva’s job is to help us chew, swallow, talk, and even digest. But saliva is much more interesting and complicated than that. Ira talks with Chris Gorski, editor at Chemical & Engineering News, who reported this story about taste and saliva for Knowable Magazine earlier this year.

Last fall, New York City’s Sanitation Commissioner Jessica Tisch stood in front of a microphone and announced her plan to deal with NYC’s most hated residents: rats. She went on to make a now-viral declaration: “I want to be clear, the rats are absolutely going to hate this announcement. But the rats don’t run this city: We do.” Soon after, NYC announced its search for a rat czar. Someone who is “highly motivated and somewhat bloodthirsty” with “the drive, determination, and killer instinct needed to fight the real enemy—New York City’s relentless rat population.”

This news—and the memes born from it—put rats in the forefront of city dwellers’ minds. And now, the newly appointed rat czar Kathleen Corradi’s reign has begun. But ridding cities of rats is no easy feat. It requires public participation, new policy, behavioral changes, and an all-hands-on-deck approach from several government departments. So what’s it going to take to rid cities of rats? And is it even possible? In this live call-in, Ira talks with Bethany Brookshire, science journalist and author of Pests: How Humans Create Animal Villains, and Dr. Bobby Corrigan, urban rodentologist and pest consultant. They discuss the history of humans’ relationships with rats, why these critters thrive in cities, and why we’ll need to learn how to live with them.

Transcripts for each segment will be available the week after the show airs on sciencefriday.com.

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