Hi.
Sorry if I'm asking a well-known question such as this, but how do you imagine Sigil's ring-like shape?
In the Campaign Setting is says that the ring has 5 miles diameter and 20 miles circumference: does this mean it's a rotational solid made from a 5 mile diameter circle that rotates on a circle of mean circumference 20 miles long? That would mean it's a Very fat ring.... way far from any depiction of the city that you can find.
Also, the city is built on the internal concave surface of the ring, but what's the angular width of the sector? If we take the "wheeltyre" example model, the city should fold over itself (have an angular width > 180°).
In any case, how much of the "nothingness" outside Sigil is visible from the streets?
What's your position about this issue? Is there any canon information that can be used?
Thanks very much.
P.S. Let's ignore the fact that The Lady can shrink or enlarge the city at will.
As a commentary on the dimensions of Sigil - arguably the 5-mile dimension measures the width of the city from rim-to-rim, not the diameter of the ring itself. So it's a rotational solid made from a circle with a (5*2=10) mile cicumference, and a diameter of only about 1.6 miles, rotating around a circle with 20 mile circumference. That's a lot closer to established art.
The angular width of Sigil, meanwhile, is IMHO exactly 180°, with the extreme edges of the city lining up with one another. If any of my players try and prove that that sort of angular width would cause cramping for tall buildings butting tops with one another, I politely ask them for the math book used to back up their notes, then beat them with it.
(This all assumes that Sigil works on pure Euclidean geometry, of course. It probably doesn't, at least a lot of the time.)
As for the "nothingness", some of it can be viewed from the streets of Sigil, but not much. No exact measurements have ever been calculated - though it seems that every generation has one or two ambitious Guvners who want to try. The fortunates among this lot generally get released to the Bleakers' custody two or three months after they start on their work.