How Many Habitable Planets Are In The Milky Way?

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Why Aliens Can’t Build Rockets – The Oxygen Bottleneck

Why Aliens Can’t Build Rockets – The Oxygen Bottleneck

Why some alien civilizations may never reach space 🚀 Without enough oxygen, fire fails—and without fire, industry, rockets, and stars remain forever out of reach. 🚀 Join this channel to get access to perks:...

The Fermi Paradox: Air — Atmospheres as a Great Filter

The Fermi Paradox: Air — Atmospheres as a Great Filter

Why is air the rarest and most crucial ingredient for life? We explore how atmospheres form, fail, and filter entire worlds—and how this shapes the Fermi Paradox and the search for alien civilizations. Get Nebula using my link for 50% off an annual...

Hidden Alien Empires: Shadow Civilizations & Exostellar Realms

Hidden Alien Empires: Shadow Civilizations & Exostellar Realms

What if alien civilizations exist—but chose to hide? Exploring shadow empires, cosmic silence, and the limits of secrecy in space. Get Nebula using my link for 50% off an annual subscription: https://go.nebula.tv/isaacarthur Check out Mad Kings:...

How Big Could a Space Habitat Get?

How Big Could a Space Habitat Get?

How big could space habitats really get? From O’Neill cylinders to Ringworlds and Topopolises, we explore the true limits of megastructure scale. Get Nebula using my link for 50% off an annual subscription: https://go.nebula.tv/isaacarthur Watch my...

Cryosleep Isn’t About Sleeping — It’s About Time Management

Cryosleep Isn’t About Sleeping — It’s About Time Management

Cryosleep isn’t futuristic napping—it’s pausing biology so the universe can catch up. Time management, not sleep. 🚀 Join this channel to get access to perks: https://www.youtube.com/channel/UCZFipeZtQM5CKUjx6grh54g/join 🛒 SFIA Merchandise:...