 If you missed any part of this program or would like to hear it again, subscribe to our podcasts or ask your smart speaker to play Science Friday. Every day now is Science Friday. And you can join us throughout the week on social media or with our newsletters, sciencefriday.com slash newsletters. Or email us. The address is scifri at sciencefriday.com. Ira's back next week. I'm Anna Rothschild.