In tomorrow’s world, cities may rise into the clouds, dive beneath oceans, or float among the stars—join us as we journey through these radical urban frontiers.

Watch my exclusive video Antimatter Propulsion: Harnessing the Power of Annihilation - https://nebula.tv/videos/isaacarthur-antimatter-propulsion-harnessing-the-power-of-annihilation
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 gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $30.
 
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:
Cities of the Future 
Episode 498; May 8, 2025
Written, Produced & Narrated by: Isaac Arthur
 Edited by: Briana Brownell & Thomas Owens
Graphics: Bryan Versteeg, Ervin Oprea, Ken York YD Visual, Sergio Botero
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
Chris Zabriskie, "Unfoldment, Revealment", "A New Day in a New Sector", "Wonder Cycle"
Taras Harkavyi, "Alpha and..."
Stellardrone, "Red Giant", "Billions and Billions"

498 V Cities of the Future May 8, 2025

Why wait centuries to terraform Mars when you could build a habitable world overnight? In this episode, we explore the concept of Worldhouses—planet-spanning domes that let us colonize hostile worlds by enclosing them beneath engineered skies, one dome at a time.

Watch my exclusive video Antimatter Propulsion: Harnessing the Power of Annihilation - https://nebula.tv/videos/isaacarthur-antimatter-propulsion-harnessing-the-power-of-annihilation
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 gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $30.

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:
Worldhouses
Episode 499; May 15, 2025
Written, Produced & Narrated by: Isaac Arthur
Graphics: Fishy Tree & Ken York YD Visual
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
Chris Zabriskie, "Unfoldment, Revealment", "A New Day in a New Sector"
Taras Harkavyi, "Alpha and..."
Stellardrone, "Red Giant", "Billions and Billions"

Worldhouses & Paraterraforming (Narration Only)

From trench-busting stormtroopers to galaxy-spanning clone legions, we explore the evolution of elite soldiers and how sci-fi reimagines the future of warfare.

Watch my exclusive video Antimatter Propulsion: Harnessing the Power of Annihilation - https://nebula.tv/videos/isaacarthur-antimatter-propulsion-harnessing-the-power-of-annihilation
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 gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $30.

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:
Stormtroopers: Elite Warriors and the Evolution of Future Combat 
Episode 501; May 29, 2025
Written, Produced & Narrated by: Isaac Arthur
Editors: Donagh Broderick
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
Markus Junnikkala, "A Fleet Behind the Moon"
Phase Shift, "Forest Night"
Chris Zabriskie, "Unfoldment, Revealment" & "A New Day in a New Sector"
Stellardrone, "Red Giant"

Stormtroopers: Elite Warriors and the Evolution of Future Combat

Stormtroopers: Elite Warriors and the Evolution of Future Combat (Narration Only)

From Clarke’s Sentinel to deep-space defense systems, this episode dives into the idea of machine monitors—guardians of planets, civilizations, and secrets too ancient to name.

Watch my exclusive video Antimatter Propulsion: Harnessing the Power of Annihilation - nebula.tv/videos/isaacarthur-a…ower-of-annihilation
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 $30.

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: Machine Monitors
Episode 444b; May 1, 2024 
Produced, Written & Narrated by: Isaac Arthur
Music Courtesy of:
Epidemic Sound http://epidemicsound.com/creator

Ancient Machine Monitors: Alien Watchdogs, AI Custodians, and the Fermi Paradox (Narration Only)

Ancient Machine Monitors: Alien Watchdogs, AI Custodians, and the Fermi Paradox

A new industrial revolution is coming—not on Earth, but above it. This episode delves into how orbital shipyards will produce everything from shuttles to megastructures, changing how we explore and inhabit space.

Watch my exclusive video Fishbowl Starships - Water As Shielding - https://nebula.tv/videos/isaacarthur-fishbowl-starships-water-as-shielding
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 gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $30.

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:
Orbital Shipyards: Building Fleets in Space
Episode 722; June 5, 2025; Nebula Exclusive
Written, Produced, & Narrated by: Isaac Arthur
Graphics: 
Anthrofuturism
Bryan Versteeg
Fishy Tree
Jeremy Jozwik
Melanovis
Sergio Botero
SpaceResourcesCGI
Udo Schroeter
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
Phase Shift, "Forest Night"
Kai Engel, "Endless Story of Sun and Moon"
Chris Zabriskie, "Unfoldment, Revealment", "A New Day in a New Sector", "Oxygen Garden"
Stellardrone, "Red Giant", "Billions and Billions"

Chapters
0:00 Intro
0:15 Why Build in Orbit?
1:29 The Gravity Well Problem
3:22 Material Sourcing – The Importance of ISRU
5:44 Early Orbital Shipyards – Existing & Near-Future Projects
6:37 Lessons from Space Stations & Prototypes
8:22 Port George & Linus Scrapyard – Revisiting Fictional Shipyards
13:08 Infrastructure & Logistics of Orbital Shipyards
23:39 Constructing Different Types of Ships
31:58 Challenges of Large-Scale Shipbuilding
34:10 Maintenance, Repairs, and Refits – Sustaining a Spacefaring Fleet
39:25 Salvage and Recycling
40:37 The Future of Orbital Shipyards – Expanding Beyond Earth
43:03 The Rise of Megastructure Shipyards
44:29 Privatization and the Spacefaring Economy
46:12 Shipyards as Strategic Military and Political Assets
47:54 The Role of AI, Automation, and Post-Human Workforces

Orbital Shipyards - Building Fleets in Space (Narration Only)

The Fermi Paradox asks why, in a vast and ancient universe, we see no signs of alien life. In this episode, we explore five explanations that make sense—and seven popular ones that, despite sounding good, fall flat under closer scrutiny.

Join this channel to get access to perks:
https://www.youtube.com/channel/UCZFipeZtQM5CKUjx6grh54g/join
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:
5 Fermi Paradox Explanations I Love, 7 That Fall Flat
Episode 502 / 721; May 31, 2025
Written, Produced & Narrated by: Isaac Arthur
Graphics: Ken York YD Visual
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator

0:00 Intro
1:11 Space Is Too Big
4:46 Rare Earth
6:35 Aliens Signals Just Can’t Be Heard
10:09 Humans Are Boring
11:36 Dark Forest Theory
14:14 Interdiction Bubble Civilizations
16:49 Hermit Hypothesis
19:18 Aestivation Hypothesis and Extragalactic Migration
21:10 Transcendance, Ascension, and Extra-Universe Migration
22:33 Infinite Miniaturization
23:33 Berserkers & Zombie AI
24:53 Aliens Common But Unrecognizable 
26:08 Simulation Hypothesis


5 Fermi Paradox Explanations I Love… and 7 That Fall Flat (Narration Only)

5 Fermi Paradox Explanations I Love… and 7 That Fall Flat

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.

Watch my exclusive video Fishbowl Starships - Water As Shielding - https://nebula.tv/videos/isaacarthur-fishbowl-starships-water-as-shielding

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 gift.nebula.tv/isaacarthur to give a year of Nebula to a friend for just $30.


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:

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"