Mirrors versus diffuse reflection

Dr. Omni wrote:
> I have been thinking about designs for spherical and cylindrical
rotating habitats following what I call "Frazer's
Guidelines" ...because John Frazer was the first one that I saw
mentioning them, in the Space Settlers list...

First on this list, maybe. I cribbed most of it from Andrew
Nowicki's "greenhouse" model habitat, and A.C. Clarke's "Rama"
spacecraft. I did roughly develop most of the rest of it (with some
help from members of the LUF email lists): the "light ducts"
admitting light through the floor of the hab to the opposite side of
the interior, glass block mirrors/deflectors/difusers, etc.
Note that such "light ducts" may also work through very great
thicknesses of floor space, such as under-levels of decks for
machinery or habitation under the inner open volume.
Nowicki has most of the good work on focussed sunlight entry in
print, and Clarke definately originated the "light emmiter" slit or
spot on the opposite landscape floor (albeit using rather "soft" S.F.
artificial energy & light).

> At first, as usual, I thought about mirrors inside the colony to
disperse the incoming sunlight in a useful way. But after a while I
thought: wouldn't simply making the sunlight hit an opaque and purely
white surface be a simpler and cheaper alternative to a mirror system?

How about a polished, but pebbled-textured aluminum surface?
(pebbled texture, to diffuse the light, but polished for efficient
reflection)
Overall, this sounds a little like the "hatbox" design, or
the "sunflower". Redirect the sunlight to the land surface, after
it's already been reflected into the hab volume.

I take it the polished reflecting surface is an end cap? Remember
that dust won't settle onto it: It's vertical with referrence to
local gravity, and the gravity is nil.

With referrence to the light ducts, why not just have a small "Rama"
type hole or spot in the landscape, which shines light onto a broad
area of landscape overhead?
We don't know about the intensity of sunlight needed to be piped in
through a duct, and we don't know about the intensity of convergent
beams of light in the center of the hab.

Any of these design options are high maintenance (but so are the
huge, fragile, rotating exterior mirrors of O'Neill's designs).
The "Island One" Bernal sphere comes closest to any of these ideas:
small window area, with most mirror being non-rotating.