Galaxy-Scale Megastructures & Kardashev-3 Civilizations

Imagine engineering projects so vast they mold galaxies into new shapes. We’ll explore the staggering feats of Kardashev-3 and beyond civilizations, crafting CARD galaxies, Birch Planets, and even rearranging superclusters.

Watch my exclusive video Dark Biospheres: https://nebula.tv/videos/isaacarthur-dark-biospheres-life-on-worlds-without-sunlight

Get Nebula using my link for 40% off an annual subscription: https://go.nebula.tv/isaacarthur

Get a Lifetime Membership to Nebula for only $300: https://go.nebula.tv/lifetime?ref=isaacarthur

Use the link https://gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $36.

Visit our Website: http://www.isaacarthur.net

Join Nebula: https://go.nebula.tv/isaacarthur

Support us on Patreon: https://www.patreon.com/IsaacArthur

Support us on Subscribestar: https://www.subscribestar.com/isaac-arthur

Facebook Group: https://www.facebook.com/groups/1583992725237264/

Reddit: https://www.reddit.com/r/IsaacArthur/

Twitter: https://twitter.com/Isaac_A_Arthur on Twitter and RT our future content.

SFIA Discord Server: https://discord.gg/53GAShE

Credits:

Spaceport Innovations - Designing the Next Generation of Launch Sites

August 3, 2025; Episode 746

Written, Produced & Narrated by: Isaac Arthur

Galaxy-Scale Megastructures & Kardashev-3 Civilizations

Written by: Isaac Arthur

Editor: Darius Said

Graphics: Jeremy Jozwik, Ken York, Sergio Botero, Steve Bowers

Select imagery/video supplied by Getty Images

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

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

See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.