Botanist and founder of <a href="https://blackbotanistsweek.weebly.com/"target="_blank" >#BlackBotanistsWeek</a> Tanisha Williams explains why some leaves change color during fall and what shorter days and colder temperatures have to do with it. Plus, a bit of listener mail from you! (Encore) You can always reach the show by emailing <a href="mailto:shortwave@npr.org"target="_blank" >shortwave@npr.org</a>. We're also on Twitter <a href="https://twitter.com/NPRShortWave"target="_blank" >@NPRShortWave</a>! See <a href="https://pcm.adswizz.com">pcm.adswizz.com</a> for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. <a href="https://www.npr.org/about-npr/179878450/privacy-policy">NPR Privacy Policy</a>

The Tigray Medical System Collapse

New discoveries, everyday mysteries, and the science behind the headlines — in just under 15 minutes. It's science for everyone, using a lot of creativity and a little humor. Join hosts Emily Kwong and Regina Barber for science on a different wavelength. Support public media by joining NPR+ at plus.npr.org. You’ll get perks for over 25 NPR podcasts, including sponsor-free listening for Short Wave.