Black Hole Spaghetti Mega-Habitat

The Concept — Tidal Gravity

Rotating space stations produce an undesirable side-effect, which is called the Coriolis effect. The effects on human health are not very well-understood, because the studies of continued exposure were very limited and undertaken a long time ago. Because this will very probably be a major problem for future inhabitants of space, we enter into a state of tradeoffs between requiring more material for larger gravity wheels and subjecting inhabitants to greater Coriolis forces, and the health impacts that brings.

Breaking Length and Mass

Building a space station, you are limited by materials. The essence of this reality can be expressed by several parameters, but many of them are very unwieldy to get an intuitive grasp. For the situation I describe here, the notion of breaking length is by far the most fruitful:

Industrially Viable Zone

This constraint allows us to formulate the math for the range of radii that habitats could exist.

Basic Bounding Mathematics
Range where we can put a habitat, in terms of M and r
Small zoom, this shows the neighborhood of the smallest black holes this would be viable for, which starts in the neighborhood of 1.5 x 10²⁸ kilograms. Smaller than that, and the habitat will have a substantial size relative to the event horizon’s size, and that’s anathema to this concept.
You can see that the lower-radius bound is coming from a different constrain now, and this is the event horizon itself, which grows linearly with the mass of the black hole. In actuality, 1e39 is around the size of the largest black hole ever discovered.

The Problem — Escape Velocity

I did a bit of a case-study with a stellar-mass black hole of 5 times the mass of our sun. This yields a radius range that is extremely tight compared to the distance that Earth orbits the sun from. The outer edge of this range (where the habitat would be exactly 300 km in length) would have an escape velocity of 76 km/s. For reference, it takes a little less than 10 km/s to get into orbit from the surface of Earth. Any Delta V of this value would be outright impossible with chemical propulsion, and would require some kind of ion drive.

Habitat Geometry

The habits could be a ring fully encircling the black hole, sure. To me, though, this seems like an irrelevant point. Since the different parts of the ring are self-contained pressurized habitats, and since they are all independently orbiting in a stable orbit, any given section of a ring could be considered its own independently functioning space habitat. Connecting the atmospheres between multiple sections of the ring is possible, physics just doesn’t impose any additional constraints, and this would all be up to the prerogative of the inhabitants.

 by the author.



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store


Obligatory analytical writing, online participation account for Medium. Engineering, software, books, space, constant daydreaming.