The moon Gravelworld orbited past the edge of the giant planet's Roche limit, just outside its sprawling ring system.
The ring debris was steadily disintegrating as it spiraled toward the gas giant's atmosphere, but the moon maintained its precarious orbit through the interplay of tidal forces which also heated its interior.
One billion years from now, when the largest moon came closer, this strange dance would end.
Most of Gravelworld was molten by the changing tides from the other moons. The flooded interior was easy for wormlike creatures to penetrate.
Unlike the universe's edge dwellers, forced to fight their endless wars on sliver-strips of planetary surfaces, the ice worms had an immense volume to evolve in.
For countless millennia they ignored the outside universe. It was heresy to even believe in open space. Reality stopped just below the surface.
The hot planet Redball circled its star in just five days. The sun blazed ominously in the sky, almost close enough to touch. Contraction quakes periodically rocked the surface.
In the past million years, the average temperature had dropped to 1300 degrees, and it began to rain freezing lava. Long ago the surface had become too cold for the original inhabitants, who had retreated into the molten interior.
There their evolution sped up. Chromium worms evolved flexible segments made of strange alloys. Their memories were recorded in zirconium crystals.
The two worlds existed in the same universe at roughly the same time, although they were incalculably far apart. The inhabitants of each world finally deduced their home orbited a much larger sphere, though they got most of the details wrong.
The two species could hardly have been more different in composition, but heat and cold were only relative.
Through an incredibly unlikely yet ultimately inevitable coincidence, their thoughts and perceptions were completely identical, and they would remain that way until the inhabitants finally broke through the surface, or measured certain constants of physics.
Comment Page
The best hard SF novel: Infinite Thunder by Jack Arcalon.
Buy the book
Read chapters