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"

How Many Alien Civilizations Are There? (Narration Only)

Could we sculpt dead planets into living worlds? From artificial crusts and orbital mirrors to taming tectonics and engineering biospheres, this is your definitive guide to turning alien rocks into second Earths.

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Credits:
Interstellar Travel: Can We Survive The Long Journey?
Episode 725; June 15, 2025
Written, Produced & Narrated by: Isaac Arthur
Graphics:
Jarred Eagley
Jeremy Jozwik
Ken York YD Visual
Mafic Studios
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", "Oxygen Garden", "Wonder Cycle"
Kai Engel, "Endless Story About Sun and Moon"
Taras Harkavyi, "Alpha and..."
Dark Future, "Staring Through" pt1
Miguel Johnson. "The Commanders", "Far From Home"
Lombus, "Hydrogen Sonata", "Cosmic Soup"
Aerium, "Deijocht"
Stellardrone, "Red Giant", "Solar Eclipse", "Billions and Billions"

The Terraforming Compendium - From Barren Rocks to Living Worlds (Narration Only)

Space is big—but could life out there be even bigger? Join us as we ask just how enormous alien life can get—and what it might look like.



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Credits:

Cosmic Megafauna - Could Giant Alien Life Forms Exist?

Episode 727; June 22, 2025

Written, Produced & Narrated by: Isaac Arthur

Select imagery/video supplied by Getty Images 

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

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

Cosmic Megafauna - Could Giant Alien Life Forms Exist? (Narration Only)

Explore the real economics of building and operating a space elevator—from ship-launched ribbons to megaton climbers—and how this infrastructure could change the world.

Watch my exclusive video Fishbowl Starships - Water As Shielding - https://nebula.tv/videos/isaacarthur-fishbowl-starships-water-as-shielding
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Credits:
Space Elevator Economics: Building And Operating A Superhighway To Space 
Episode 726; June 19, 2025
Written, Produced & Narrated by: Isaac Arthur
Edited by:
Adrian Nixon
Ludwig Luska
Peter Swan
Graphics:
Anthrofuturism
Atlantis Project
Katie Byrne
Phil Swan
Sergio Botero
Udo Schroeter
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"
Aerium, "Deijocht"
Stellardrone, "Red Giant", "Billions and Billions"
Lombus, "Hydrogen Sonata", "Cosmic Soup"

Space Elevator Economics - Building And Operating A Superhighway To Space (Narration Only)

Space Elevator Economics - Building And Operating A Superhighway To Space

Space colonization isn't about abandoning Earth—it's about transforming it. Discover how expanding into space can drive innovation, sustainability, and prosperity right here on the ground.

Watch my exclusive video Fishbowl Starships - Water As Shielding - https://nebula.tv/videos/isaacarthur-fishbowl-starships-water-as-shielding
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Credits:
How Colonizing Space Benefits Earth: The Ground-Level Gains of a Galactic Future
Episode 726.1; June 22, 2025
Written, Produced & Narrated by: Isaac Arthur
Graphics: Bryan Versteeg, Jeremy Jozwik, Sergio Botero
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator

How Colonizing Space Benefits Earth - The Ground-Level Gains of a Galactic Future (Narration Only)

How Colonizing Space Benefits Earth - The Ground-Level Gains of a Galactic Future

Everyone talks about terraforming Mars, but Venus might be the real prize. Discover the surprising ways we could cool, reshape, and colonize this hostile world.

Any comments, corrections, or thoughts on the video? email Isaac.Arthur.Utube@gmail.com
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Credits:
How Hard Would It Be to Terraform Venus?
June 17, 2025; Episode 725.1
Written, Produced & Narrated by: Isaac Arthur
Graphics:
Ken York
Mafic Studios
Sergio Botero
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator

How Hard WouldIt Be to Terraform Venus?

This episode explores how spaceports will evolve in design, technology, and purpose—shifting from fuel-thirsty towers to seamless transport hubs for Earth, Moon, Mars, and beyond.
Watch my exclusive video Mass Drivers on the Moon: https://nebula.tv/videos/isaacarthur-mass-drivers-on-the-moon-enabling-a-lunar-economy
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Credits:
Spaceport Innovations - Designing the Next Generation of Launch Sites
July 10, 2025; Episode 731
Written, Produced & Narrated by: Isaac Arthur
Graphics:
Anthrofuturism
Atlantis Project
Jarred Eagley
Katie Byrne
Fishy Tree
Phil Swan
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
Stellardrone, "Red Giant", "Billions and Billions"

Spaceport Innovations: Designing the Next Generation of Launch Sites (Narration Only)

Transhumanism promises a better humanity—or perhaps something no longer human at all. Join us as we explore the moral dilemmas and future paths of human augmentation.

Watch my exclusive video Mass Drivers on the Moon: https://nebula.tv/videos/isaacarthur-mass-drivers-on-the-moon-enabling-a-lunar-economy
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Credits:
How Would Aliens Behave?
July 13, 2025; Episode 732
Written, Produced & Narrated by: Isaac Arthur
Editor: Donagh Broderick
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
Stellardrone, "Red Giant", "Billions and Billions"
Taras Harkavyi, "Alpha and..."

The Ethics of Transhumanism (Narration Only)

Join us as we journey beyond the birth of the universe to unravel the mysteries of what might have preceded the Big Bang—and whether time itself had a beginning.

Watch my exclusive video Mass Drivers on the Moon: https://nebula.tv/videos/isaacarthur-mass-drivers-on-the-moon-enabling-a-lunar-economy
Get Nebula using my link for 40% off an annual subscription: https://go.nebula.tv/isaacarthur
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Credits:
Before the Big Bang - What Came Before Time?
Episode 738; July 20, 2025
Written, Produced & Narrated by: Isaac Arthur
Select imagery/video supplied by Getty Images 
Music Courtesy of Epidemic Sound http://epidemicsound.com/creator
0:00 Intro Asking the Impossible
2:08 The Limits of Time and Spacetime
7:45 Beyond the Big Bang: Alternate Beginnings
14:38 Other Realities: Higher Dimensions and Shadow Universes
18:28 Emergent Time
22:38 Bubble Collisions and Multiverse Scars
24:44 Conclusion: What Came Before Time?