A long time ago, in a galaxy far far away… we wondered, could you ever build a real lightsaber like the ones in Star Wars? A lightsaber is a glowing sword that can cut through metal – and pretty much anything else you can think of. It’s the favorite tool of heroes like Luke Skywalker and Ahsoka Tano, as well as villains like Darth Vader. That’s just in the movies, but could we make them real? We asked mechanical engineering professor Sayan Biswas to help us find the answer.

Got more questions than Luke when he was training with Yoda? Send them to us at BrainsOn.org/contact, and we’ll help use the force to find an answer!

All different kinds of giant prehistoric creatures used to walk the Earth, from 20-foot-tall sloths to sharks longer than a school bus.. They all seem huge in our imaginations, but were animals in the past actually bigger than animals on Earth now? We asked paleontologist Kristi Curry Rogers to help us find the answer.

Got a BIG question? Send it to us at BrainsOn.org/contact, and we’ll help size up the answer!

If there’s one thing that’s generally known about sharks, it’s that they have sharp teeth. But have you heard they have to keep moving to stay alive? Why is that? In this episode we talk to shark scientist Melissa Cristina Marquez about this very question.

Do you have a Moment of Um question that seems kind of fishy? Send it to us at BrainsOn.org/contact, and we’ll chew on the answer.