Fins
The heat exchanger fins, referred to in Titan as "solar absorption sails" and "solar panels", where the fluids carried by the enormous conduits that make up the cable strands are pumped, getting superheated on the sunside or supercooled on the darkside.
By directing the subterranean flow of hot or cold fluids, Gaea is able to maintain a variety of
ecologies; dry deserts, frozen wastelands, marshes, rainforests, fertile plains, glaciers and wide
seas to name a few.
At this point, the fins are the most incongruous part of this model. They do not match any of
the art of the books in size or shape. Symmetry has a big role in Gaean anatomy. Long ago, I
noticed how the shape of the fins could be derived by drawing six circles around the edge of her
circumfrence. The resulting spaces between the circles match the general shape of the fins in the
'official' art, just larger and more curvy. Sacred geometry buffs will recognize the shape, as
will beehive fans.
I tried to make smaller fins, basing their maximum outward extent on the Saturnian moon Rhea,
Gaea's birthplace. Rhea has a mean diameter of 1528 km, radius of 764 km. This would make the
fins extend only 114 km from the rim, making them much smaller than they appear in the book art.
For now I'll keep them the way they are, mostly because of the pretty pretty math. The picture
above shows top and side views, to illustrate how thin they are. On this model, their maximum
thickness, at the rim, is 5 km. If anybody thinks they should be thicker for structural or
functional reasons, feel free to let me know.