A Shellworld is a large artificial planetoid.
They are also known as Shield Worlds, Hollow Worlds, Machine Worlds, Veil Worlds, or Slaughter Worlds.[1]
History
Approximately 4000 Shellworlds were constructed by the Involucra. By the early 20th century CE only 1332 remained, with 110 of those in a collapsed state, and 86 being Dra'Azon Planets of the Dead.[1]
The Iln spent many millions of years destroying Shellworlds before disappearing. No record of their reasons survived into the 20th century CE.[1]
Astronomical Positions
The Shellworlds were placed around stable main-series stars in two and five hundred million kilometre radius orbits. When built they had been placed regularly around the outskirts of the galaxy but had since drifted due gravitational influences.[1]
Construction
They are made of concentric spherical levels supported by one million gigantic towers and their materials are virtually indestructible.
Types
Arithmetic
Arithmetic Shellworlds had 15 levels each regularly spaced levels at 1400 kilometre intervals. They had external diameters of 45000 kilometres.[1]
Incremental
On Incremental, of Exponential, Shellworlds the intervals between levels increased as one became more distant from the core. The intervals were determined by a number of logarithm-based ratios. The size of these worlds varied with the largest examples being almost 80000 kilometres across.[1]
Incremental Shellworlds make up roughly 12% of the surviving population.[1]