As one of the most successful creators on YouTube, Mark Rober doesn’t see what he does as a business. Instead, it’s a way to celebrate science in the most joyful way possible. While working as an engineer at NASA, he made his YouTube debut with a tutorial on how to make a gory Halloween costume with two iPads and a lot of duct tape. Over time, his videos became more elaborate, including a belly flop into a pool full of Jello, and a demo of a glitter-fart bomb to get revenge on porch pirates. Within a few years, Mark was teaching online science classes and selling subscription boxes for kids. Today, his YouTube channel has 5.5 billion views, 48 million subscribers…and–astonishingly, given that audience–less than 150 videos. This episode was produced by J.C. Howard, with music by Ramtin Arablouei Edited by Neva Grant, with research help from Sam Paulson. You can follow HIBT on Twitter & Instagram, and email us at hibt@id.wondery.com. Learn more about your ad choices. Visit podcastchoices.com/adchoices