Are we alone in the universe—or just early to the party? We’ll explore the math, models, and megastructures that might answer how many alien civilizations are out there, and why the night sky remains so quiet.

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Credits:

How Many Alien Civilizations Are There?

Episode 723; June 8, 2025

Written, Produced & Narrated by: Isaac Arthur

Editor: Ludwig Luska

Graphics: Ken York YD Visual

Select imagery/video supplied by Getty Images

Music Courtesy of Epidemic Sound http://epidemicsound.com/creator

Phase Shift, "Forest Night"

Chris Zabriskie, "Unfoldment, Revealment" & "A New Day in a New Sector"

Koalips, "Kvazar"

Stellardrone, "Red Giant" & "Billions and Billions"

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