Uploaded September 2025 | Updated September 2026, 2 weeks ago
From O’Neill cylinders to spiral habitats, discover how humanity might build colossal, interconnected cities high above Earth.
Watch my exclusive video The Economics of Immortality: nebula.tv/videos/isaacarthur-the-economics-of-immortality
Get Nebula using my link for 40% off an annual subscription: go.nebula.tv/isaacarthur
Get a Lifetime Membership to Nebula for only $300: go.nebula.tv/lifetime?ref=isaacarthur
Use the link gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $36.
Visit our Website: isaacarthur.net
Join Nebula: go.nebula.tv/isaacarthur
Support us on Patreon: patreon.com/IsaacArthur
Support us on Subscribestar: subscribestar.com/isaac-arthur
Facebook Group: facebook.com/groups/1583992725237264
Reddit: reddit.com/r/IsaacArthur
Twitter: twitter.com/Isaac_A_Arthur on Twitter and RT our future content.
SFIA Discord Server: discord.gg/53GAShE
Credits:
Orbital Arcologies - Mega Cities in Space
Written, Produced & Narrated by: Isaac Arthur
Graphics: Bryan Versteeg, Jeremy Jozwik, Katie Byrne, Udo Schroeter
Select imagery/video supplied by Getty Images
Music Courtesy of Epidemic Sound epidemicsound.com/creator
Chapters
0:00 Intro - The Conductor’s Tale
4:43 Why Megacities in Space?
6:02 The Four Foundational Assumptions of Space Habitat Design
10:11 Flawed Assumptions & Specialized Habitats
11:28 The Urban Web – Tethered Transit and Megacity Growth
17:14 Nebula
18:24 Spiral Habitats – A Rolled-Up City in Space
20:19 Density and Design – Population Scaling
23:17 Green Limits – CO₂, Heat, and Living Space
26:08 The Future of Orbital Urbanization – Terran Swarms and Beyond
From O’Neill cylinders to spiral habitats, discover how humanity might build colossal, interconnected cities high above Earth.
Watch my exclusive video The Economics of Immortality: nebula.tv/videos/isaacarthur-the-economics-of-immortality
Get Nebula using my link for 40% off an annual subscription: go.nebula.tv/isaacarthur
Get a Lifetime Membership to Nebula for only $300: go.nebula.tv/lifetime?ref=isaacarthur
Use the link gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $36.
Visit our Website: isaacarthur.net
Join Nebula: go.nebula.tv/isaacarthur
Support us on Patreon: patreon.com/IsaacArthur
Support us on Subscribestar: subscribestar.com/isaac-arthur
Facebook Group: facebook.com/groups/1583992725237264
Reddit: reddit.com/r/IsaacArthur
Twitter: twitter.com/Isaac_A_Arthur on Twitter and RT our future content.
SFIA Discord Server: discord.gg/53GAShE
Credits:
Orbital Arcologies - Mega Cities in Space
Written, Produced & Narrated by: Isaac Arthur
Graphics: Bryan Versteeg, Jeremy Jozwik, Katie Byrne, Udo Schroeter
Select imagery/video supplied by Getty Images
Music Courtesy of Epidemic Sound epidemicsound.com/creator
Chapters
0:00 Intro - The Conductor’s Tale
4:43 Why Megacities in Space?
6:02 The Four Foundational Assumptions of Space Habitat Design
10:11 Flawed Assumptions & Specialized Habitats
11:28 The Urban Web – Tethered Transit and Megacity Growth
17:14 Nebula
18:24 Spiral Habitats – A Rolled-Up City in Space
20:19 Density and Design – Population Scaling
23:17 Green Limits – CO₂, Heat, and Living Space
26:08 The Future of Orbital Urbanization – Terran Swarms and Beyond
