Drawing of the space habitat

It appears that a number of people are misunderstanding my description of the space habitat (on the order of the "invasion fleet being swallowed by a small dog" scale).

So here's a picture, approximately to scale:

(Edited to correct drawing the moon orbit too small.)

The large circle is the earth's orbit. The circle in the middle is the Sun. The little circle on the left, that's the Moon's orbit around Earth. (Earth itself is a teensy dot in the middle of that circle, about as big as the line marking the orbit of the Earth around the Sun. I drew the Earth in, but you probably can't see it in the small image). The relatively large circle on the right, that's the space habitat sitting at a Lagrange point (or rather, sitting with a Lagrange point at its centre). It is so phenomenally big it might not actually be stable here (I have not done the calculations to check).

(By comparison, the original Ringworld would be represented by the really big circle. Much larger.)

Now the habitat goes around the Sun in the same orbit as the Earth, offset by 60 degrees. It rotates about its own central axis once every 24 hours, giving it a day-night cycle. The ring would be tilted a little, so it doesn't shade itself most of the time - in fact the ring will precess as it goes. The artificial gravity induced by the rotation would be about 1g (it would, I think, vary somewhat between night and day, because at midnight you're orbiting a fair bit nearer to the Sun than you "should" for the center of mass of the habitat, and midday you're a bit further from the Sun).

Government in SF - a failure of imagination?

(Within this post, I'm going to take the stance that SF stands for "speculative fiction" rather than science fiction. My main reason is that SF these days rarely contains much actual "sciency" stuff, and the category has become so broad that the term "science fiction" is not even vaguely true of most of it. It is also possible that it serves my argument. )

I've long had a problem with how government is represented in SF, particularly film and television, but it also happens in written SF - that the governments almost always seem to be of only two very narrow types:
(i) near-absolute monarchy (though possibly called an emperor or something, often also with a noble class);
(ii) US-style presidential democracy.

I have no doubt that in many stories, these are plausible models. However, I simply cannot fathom why so many writers assume that if it's not the first, it must be the second. Sometimes the US political system is reproduced to an astonishing level of detail, including a near duplicate constitution and everything.

According to wikipedia:
- there are 123 democratic countries
- there are 72 parliamentary democracies
- in addition, there are a large number of "hybrid" models (particularly in Eastern Europe)

That is, a US-style democracy is by far in the minority. On earth, parliamentary-style democracies are the rule. Yet in SF, they're almost unheard of.

So why in visual-media SF (the majority of whose writers are from the US), if you don't have some form of monarchy or monarchy analogue, will it be (apart from a very few exceptions), a US-clone democracy, often down to its boot-buckles? Is this a failure of imagination? Are US film and TV writers largely unable to imagine anything else? Are they unaware of anything else? Or do they imagine that a US audience won't accept anything else (and everyone else will, presumably)? If it's the last, that, too, is a failure of imagination - I certainly don't believe US fans of SF are that unimaginative and unwilling to think about different ideas.

Obviously, people tend to write about what they're familiar with, but if you only ever write about only what's in your back yard, your fiction hardly deserves the name "speculative".

Come on, people, have a look at the world around you. Try a different model for government once in a while!