Seashells may seem like a small topic for a book, or a podcast. But when we look into them deeply, we find that they reveal startling truths about our oceans, our planet, and ourselves. This week Cynthia Barnett joins Adam to talk about the surprising history of seashells and her new book The Sound of The Sea. You can check out her book at factuallypod.com/books. Learn more about your ad choices. Visit megaphone.fm/adchoices