Isaac Arthur

Where in the Universe Is Life Most Likely?

Earth may not be the Universe’s best home for life. We compare archipelago worlds, waterworlds, ocean moons, red dwarfs, rogue…

How Do You Defend a Space Colony? | Beyond Space Defense

In space, every ship, tug, mass driver, and power beam can become a weapon. We explore how future stations and…

Beyond Space Defense: War, Sabotage & Survival Beyond Earth

In space, every ship, tug, mass driver, and power beam can become a weapon. We explore how future stations and…

The Fermi Paradox: Civilization Extinction Cycles

What if alien civilizations are common, but keep collapsing before they can spread across the galaxy? We explore civilization extinction…

What Is the Largest Possible Star?

How big can a star actually get before gravity, radiation pressure, and violent mass loss tear it apart? The most…

White Holes: Do They Exist?

White holes are black holes run backward: nothing can enter, but matter and light can escape. We explore whether these…

Why Space Is Not Actually Cold

Space looks freezing, but “cold” works very differently in a vacuum. Without air to carry heat away, objects in space…

Could You Deadlift an Asteroid?

Could you actually deadlift an asteroid in low gravity? It sounds absurd, but depending on the asteroid, your body, and…

How Big Could Human Civilization Get?

How big could human civilization become? From trillion-person worlds to Dyson swarms, galaxy-spanning cultures, and digital minds, we explore just…

Floating Cities Above Gas Giants

Why build floating cities above Jupiter and Saturn? Not for fusion fuel, but for something far more valuable: the staggering…

The First Space Elevator: Where Would We Build It?

If we could build a space elevator tomorrow, where should it go? Earth may be the obvious answer, but the…

What Is the Fastest Thing Humans Have Ever Built?

What’s the fastest object humanity has ever built—and how did we get it moving that fast? The answer involves a…

Ion Drives: The Slow Rockets That Win Space

Ion drives are slow, quiet, and astonishingly efficient. From asteroid freighters and Mars cargo ships to the infrastructure behind future…

The Wow! Signal: Alien Message, Cosmic Fluke, or SETI’s Best False Alarm?

For 72 seconds, the universe seemed to answer SETI. The Wow! Signal was strong, narrowband, and strangely convincing... but it…

Could We Detect Earth From 100 Light Years Away?

Could an alien civilization 100 light-years away tell Earth is inhabited? We explore what our atmosphere, radio signals, city lights,…

Dark Biospheres – Life on Worlds Without Sunlight

Could life thrive without sunlight? Explore dark biospheres on rogue planets, icy moons, and buried oceans, where chemistry, tidal heating,…

What Happens Inside a Black Hole?

What really happens when you fall into a black hole? We explore event horizons, spaghettification, what you’d see inside, possible…

Could a Planet Be Bigger Than Jupiter?

Could a planet grow bigger than Jupiter? Only slightly. Add more mass, and gravity starts crushing it inward instead, leading…

Megacorporations in Space

From company towns in orbit to corporate empires among the stars, could megacorporations build the space frontier... or end up…

Why Aliens Might Use Lasers Instead of Radio

The First Martian Cities: Planning Habitats

Mars won’t get cities because it becomes easy to live there. It gets cities because people stay. We explore how…

What If Aliens Are Watching But Won’t Intervene?

What if advanced aliens are quietly watching Earth but refuse to interfere? Explore the cosmic zoo hypothesis, why silence may…