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I will call the two circles along the plane of rotation the equators (the inner and outer). As for the poles, they are the circles furthest away fromthe equatorial plane. Hubward is towards the rotation axis, rimward is away from it. Planewards is towards the equatorial plane. North is towards the

closest part of the North Pole circle, south towards the closest part of the South Pole circle.

The dragon has 1.1 G gravity along the poles but just 0.75 G along the rimward equator. The hubward equator has slightly higher gravity, 0.81

G. Note that having a low gravity equator and high gravity poles does not mean stuff will roll or drift towards the poles: as mentioned before, the surface is

an equipotential surface, so gravity (plus the centrifugal correction) is always perpendicular to it.

But an air mass flowing towards the pole will be squeezed together. In fact, the different gravities will create horizontal pressure differences that

are going to interact with temperature differences to set up jet streams in nontrivial ways. The Dragon has a hubward/interior equator 8,633 km from the

center, and a rimward/exterior equator 19,937 km away. The equatorial diameter is 11,304 km.

The Dragon extends 4,070 km from the equatorial plane, with a north-south diameter of 8,141 km. The cross-section has roughly the 4:3 ratio of

an old monitor. The center of mass circle is 14,294 km from the center. The north-south circumference is 30,794 km (0.77 of Earth) while the east-west

circumference is 125,270 km (3.1 times Earth). The total area is 2.5*109km2, 4.9 times Earth, and the total volume 6.5*1012km3, 6 times Earth. The

volume/area = 1500, 70% of Earth. The day is 3.53 hours.

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For zero tilt the hubward side will never get any sunlight: the sun is always hidden below the horizon or by the arc of the world. At t he poles

the sun is moving just along the horizon, and slightly inwards there will be a perennial dawn/dusk. The temperature difference will be big, with the interior

at subarctic temperatures: this is not entirely different from a tidally locked world, and we should expect water (and maybe carbon dioxide) to condense

permanently here. The end result would be an arid (but perhaps not super-hot) outer equator, possibly habitable twilight polar regions, and an iced-over

interior.

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The fast rotation will likely produce a strong magnetic field. In fact, considering how fast these planets are rotating the aurora light over the

hub might be an appreciable fraction of solar insolation. Except that magnetic fields have an effect on cloud formation, so it's likely that the hub will never

receive sunlight anyway. The hub might have a permanent electrical storm, with a constant electric backlight behind the clouds, over a frozen landscape of

mountains twice as steep as any on Earth.

1. The magnetic field doesn't need to hit the surface, it needs to hit the upper atmosphere.

2. We don't need the most intense magnetic field to hit the atmosphere, only a strong part.

3. It's not the magnetic field that causes aurorae, but particles in the magnetic field. There will be particles and they will be spraying imperfectly through the

hole.

4. A toroidal magnetic dynamo is considerably stronger than a spherical one of the same mass.

5. The Dragon has 6 times Earth's mass.

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An even bigger artifact is the Megadisk, a scaled up version of the Alderson Disk.

The radius of the central hole is 1 light-year, and the distance to the outer edge is

10 light-years. The design is that of a floppy disk configuration, as the base

structure is only 100 kilometers thick. The total weight is 11 galactic masses

(1MG= 3 x 1041kg), of which 10 are in the Megadisk frame and 1 is air. This

provides a 1 atm pressure on both sides of the disk. The energy to assemble this

beast is about 1054joules, so a consortium of Type III civilizations could probably

handle the assignment. (There may be political problems in obtaining the 11 MG.

Attempting to exercise eminent domain over eleven galaxies cannot be an easy

job.) The Megadisk would provide a living area equivalent to 1020Earths or nearly

a thousand Big Megarings.

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Ring by Stephen Baxter

Fantastic Ornament: 110 Designs and Motifs

The Night's Dawn Trilogy

Blame!

The Algebraist

Ultraviolet light exposure (a lot of modern paper blocks UV), and acidic chemicals (also eliminated in modern paper manufacturing) cause the cellulose to

oxidize, producing organic compounds which tend to be yellow and brown in color.