ring world - the world

A millenia ago a rogue planet smashed into one of the moons orbiting our planet. The debris was pulled into orbit around the planet forming the rings. The rogue planet had also come with it's own passengers, small tardigrade like creatures made from part energy. These microscopic creatures had an incredible effect on the rings, once brought from their slumber by the energy from the sun. Through natural by-products and their energy fields, they unwittingly terraformed the rings, allowing life to begin.
The same event which caused the rings to form, caused havoc with the planet below. Massive geothermic events choked the atmosphere and killed off all life. However, the same tardigrade type creatures made it down to the planet too, and who knows how they have changed life down there.
For the peoples who inhabit the rings however, the planet is merely another mysterious object in the night sky, as unreachable as the moon. Not to mention they have more pressing matters to deal with, such as surviving.

The rings are made up of chunks of land, ranging anywhere from a hundred miles to a few feet across. In reality the larger chunks should have fallen into the planet by now, or been broken up into smaller chunks: another side effect of the energy produced by the tardigrades?
Flight is possible between landmasses if or when the means are available, and some are so close it would be possible to bridge them with the right resources.