For the vast majority of international travelers, a passport is a necessity. But why?

 Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

<p>For the vast majority of international travelers, a passport is a necessity. But why?</p><p> </p> Learn more about your ad-choices at <a href="https://www.iheartpodcastnetwork.com">https://www.iheartpodcastnetwork.com</a>

Whether the topic is popcorn or particle physics, you can count on BrainStuff to explore -- and explain -- the everyday science in the world around us.

BrainStuff

For the vast majority of international travelers, a passport is a necessity. But why?

How Does Night Vision Work?

https://api.omny.fm/orgs/e73c998e-6e60-432f-8610-ae210140c5b1/clips/d97527ca-1c68-4f2b-b8d1-ae3200657f10/transcript