Micro Planets: Building Artificial Worlds with Black Hole Cores

Isaac Arthur (Science & Futurism)
Isaac Arthur (Science & Futurism)Mar 22, 2026

Why It Matters

Micro planets make space colonization economically scalable, turning planetary‑size ambition into affordable, modular habitats that could accelerate humanity’s expansion beyond Earth.

Key Takeaways

  • Small rotating habitats can provide Earth‑gravity with minimal size.
  • Micro planets use dense cores, like black holes, for gravity.
  • Enclosed shells replace atmosphere retention, decoupling climate from size.
  • Modular micro worlds enable scalable, market‑driven space settlement.
  • Economic shift favors numerous tiny habitats over megastructural megacities.

Summary

The video explores the concept of “Micro Planets,” artificial worlds whose gravity is supplied by ultra‑dense cores—often envisioned as tiny black holes—rather than by planetary mass. It contrasts traditional megastructures like O’Neill cylinders with much smaller, human‑scale habitats that feel planetary despite being only a few hundred meters across.

Key insights include the physics of scaling: a 223‑meter radius rotating ring can generate 1 g, offering a 40‑acre “home” far smaller than a Stanford Torus. Gravity depends on acceleration, not size, so dense cores can replace massive shells. Conventional materials limit the smallest Earth‑gravity planet to moon‑size, but black‑hole or stellar‑core densities break that barrier.

The presenter cites concrete numbers—two revolutions per minute, 733‑foot radius, and a 280‑foot‑wide ring—to illustrate feasibility, then compares it to the 2‑km Stanford Torus and massive O’Neill designs. He notes that osmium or iridium are too rare for bulk mass, while engineered shells can retain atmosphere without thick walls, solving micrometeoroid and radiation issues.

If such micro planets can be mass‑produced, space settlement shifts from a few colossal habitats to millions of modular, tradeable units, aligning with human preferences for smaller, upgradeable property. This could drive a post‑scarcity economy where individuals own entire worlds, fundamentally reshaping real‑estate, infrastructure, and the economics of colonizing the solar system.

Original Description

What if we built entire planets around tiny black holes? Explore engineered micro worlds, artificial gravity, and the future of compact megastructures.
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Credits:
Micro Planets - Building Artificial Worlds with Black Hole Cores
Written, Produced & Narrated by: Isaac Arthur
Graphics from Jeremy Jozwik & Ken York
Music Courtesy of Chris Zabriskie & Stellardrone
Select imagery/video supplied by Getty Images
Chapters
0:00 Intro
1:14 Small Worlds, Big Numbers
7:54 What to make it from?
11:53 What is a Micro Planet, and what is it like?
17:50 So could you go even smaller?
21:20 Nebula

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