Short Wave

Happy Independence Day, Short Wavers! Do you have plans outdoors this weekend and want to figure out just how swampy it's gonna feel? For that kind of mental preparation, we're revisiting an episode in which some meteorologists are telling us to pay more attention to dew point temperature, not relative humidity. Interested in more weather episodes? Email us your question at shortwave@npr.org [shortwave@npr.org]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave [http://plus.npr.org/shortwave]. Learn more about sponsor message choices: podcastchoices.com/adchoices [https://podcastchoices.com/adchoices] NPR Privacy Policy [https://www.npr.org/about-npr/179878450/privacy-policy]

The Andromeda galaxy [https://www.nasa.gov/image-article/nasas-chandra-shares-a-new-view-of-our-galactic-neighbor/] lies just beyond (...OK, about 2.5 million light-years beyond) our galaxy, the Milky Way. For the past hundred years or so, scientists thought these galaxies existed in a long-term dance of doom — destined to crash into one another and combine into one big galactic soup. But today on the show, Regina [https://www.npr.org/people/1082526815/regina-g-barber] and computational astrophysicist Arpit Arora [https://astro.washington.edu/people/arpit-arora] explain why a recent paper out in the journal Nature Astronomy [https://www.nature.com/articles/s41550-025-02563-1]suggests this cosmic game of bumper cars may never come to a head at all. Interested in more space episodes? Email us your question at shortwave@npr.org [shortwave@npr.org]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave [http://plus.npr.org/shortwave]. Learn more about sponsor message choices: podcastchoices.com/adchoices [https://podcastchoices.com/adchoices] NPR Privacy Policy [https://www.npr.org/about-npr/179878450/privacy-policy]

The Advisory Committee on Immunization Policy, an influential CDC committee that shapes U.S. vaccine policy, has become a flashpoint in recent weeks. Secretary of Health Robert F. Kennedy Jr. fired all 17 members and replaced them with 7 new members — many of whom do not have deep expertise in vaccines, and some of whom have spread vaccine misinformation. NPR public health correspondent Pien Huang [https://www.npr.org/people/729920828/pien-huang] was at the new working group's first meeting last week. This episode, she talks with Emily [https://www.npr.org/people/767284140/emily-kwong] about the sweeping changes they promised to how vaccine policy is made in the U.S. — and resurrected issues that have been advanced by groups that question vaccines. Read more [https://www.npr.org/sections/shots-health-news/2025/06/26/nx-s1-5438485/cdc-acip-rfk-thimerosal-vaccines] of Pien's reporting on this topic. Want us to cover more twists and turns in U.S. health policy? Or less? Either way, tell us by emailing shortwave@npr.org [shortwave@npr.org]! We'd love to know what you're hearing — and want to hear from us! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave [http://plus.npr.org/shortwave]. Learn more about sponsor message choices: podcastchoices.com/adchoices [https://podcastchoices.com/adchoices] NPR Privacy Policy [https://www.npr.org/about-npr/179878450/privacy-policy]

Since 2004, scientific research has shown that a full night of sleep may lend itself to a burst of insight in the morning [https://pubmed.ncbi.nlm.nih.gov/14737168/]. But what about the earlier stages of sleep? And what about just a nap? A research team based in Germany found that even a 20-minute nap could deliver a "eureka" moment, and published their findings in the journal PLOS Biology [https://journals.plos.org/plosbiology/article?id=10.1371%2Fjournal.pbio.3003185&utm_source=pr&utm_medium=email&utm_campaign=plos006] this week. Have a question about sleep? Email us at shortwave@npr.org [shortwave@npr.org] — we'd love to hear from you! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave [http://plus.npr.org/shortwave]. Learn more about sponsor message choices: podcastchoices.com/adchoices [https://podcastchoices.com/adchoices] NPR Privacy Policy [https://www.npr.org/about-npr/179878450/privacy-policy]

Why did the ornithologist strap a taxidermy badger to a remote controlled car and drive it around the prairie? To interrogate the secret world of animal eavesdropping in the grasslands, of course! Today on the show, we travel to the most imperiled ecosystem on the planet to unravel a prairie mystery and find out why prairie dogs are grassland engineers worth keeping tabs on. Special thanks to Andrew Spencer and the Cornell Lab of Ornithology [https://www.birds.cornell.edu/home/] for providing the Long-billed Curlew call recording, and to American Prairie [https://americanprairie.org/] for providing prairie soundscape recordings. Got a question about other animal ecosystem engineers? Email us at shortwave@npr.org [shortwave@npr.org]. Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave [http://plus.npr.org/shortwave]. Learn more about sponsor message choices: podcastchoices.com/adchoices [https://podcastchoices.com/adchoices] NPR Privacy Policy [https://www.npr.org/about-npr/179878450/privacy-policy]