A pair of ghost shoes visit Molly with a message: it's time to think about garbage. They predict that Molly will be visited by three visions of garbage, one from the past, one from the present and one from the future. Today, Producer Sanden Totten takes us on a time traveling journey to see how we started making all this trash in the first place. Plus: the Moment of Um answers the question: Are yawns contagious to animals? Next week, we'll be back with a look at the present and future of garbage. This episode was sponsored by: Mathnasium (<a href="https://www.mathnasium.com/" class="default">Mathnasium.com</a>)

How to conquer Garbage Mountain

Brains On!® is a science podcast for curious kids and adults from American Public Media. Each week, a different kid co-host joins Molly Bloom to find answers to fascinating questions about the world sent in by listeners. Like, do dogs know they’re dogs? Or, why do feet stink? Plus, we have mystery sounds for you to guess, songs for you to dance to, and lots of facts -- all checked by experts.