In this episode, we find out how a system of cables around the globe (and deep in our oceans) brings websites, songs, videos and podcasts to our phones and computers, almost at the speed of light. The internet can seem vast and intangible but there’s a very physical system of cables, servers and exchange points across the globe (and yes, even under the oceans). We’ll find out how a video shows up nearly instantly on our screens and about insanely thin, clear glass tubes are the key to our digital communication.

You can join the Brains On Fan Club at brainson.org/fanclub. This episode is sponsored by America’s Test Kitchen Kids (atkkids.com/brainson and promo code ATKKIDS10), Bona Hardwood Floor Cleaner (bona.com/brainson), Hello Products (helloproducts.com and promo code HELLOBRAIN), and KiwiCo (kiwico.com/brains). You can support the show at brainson.org/donate.