Natural Lighting for Buildings

Mike Fedderson asked me a question about how to light a tunnel with natural sunlight at the Wonders of the Day thread. To prevent things from getting too crowded there I have made a new thread for this topic specifically.

He mentioned the coke bottle sunlight method which is cheap and easy to do as demonstrated in the video below:


So, the main idea is how to get sunlight in buildings and tunnels. Some possible ways of this doing this could include:
-solar light tube (basically a cylindrical shiny piece of metal with glass ontop)


-Fiber optics could be used in similar manner. Essentially, from my understanding, a fiber optic cable is is just a long tube that has light come in one end, and it bounces around inside until it exits the other end, kinda like a solar light tube. According to an article by Building Green, this method of fiber optics for lighting deep down is more expensive than the tubular skylight method which may be a hinderance.

here is a look at how fiber optics work:


What do you all think are good ways to light a building naturally, or as Mike was wondering, a tunnel?

I've been fascinated with this idea for a long time, I pictured a glass ball in a sunny spot connected by fiber optic cord (the kind used for LED lighting, not digital) to a light diffusing fixture inside a building. Reading the descriptions of cordage, some of them come with plastic sheathing to protect them from... guess what... UV radiation. So I'm thinking that if used to transmit sunlight this cordage would quickly deteriorate and lose its usefulness/ability to transmit light. Perhaps it would be possible to coat the light collector with UV blocking film, but I'm not sure how much useful light would make it to the destination after that. I really want to figure out a way to use this principle to move natural light to where it's needed.
Maybe it would be possible to substitute pipes or UV resistant tubes filled with water and/or propylene glycol for the cord? It makes it sound too complicated to me but it's an idea. Supposedly propylene glycol is safe, but that doesn't make me want to chug a gallon of it, plus I don't know how stable it is.
I'm kinda frustrated because this threw a monkey wrench into my fantasies of how I will build my until-I-die house.

Hmmm... yeah, that is a tricky issue. Considering the manufacturing involved, a very low-tech solution to me that comes to mind is maybe just understanding that things don't have to last forever and will have to be replaced eventually.

And a lower processed (or more lcoally sourced option) could be jerry-rigging the above idea of a roof light and sun tube with mirrors to instead use:

-to replace the clear plastic roof light:
*transparent or translucent cloth (could make yourself, source it locally, etc etc)
*paper like those shoji doors (except on the roof instead) (maybe a very very thin peice of wood could work)


-to replace the sun mirror tubing
*maybe polished ceramics
*maybe polished stones from your region
*um, maybe polished anything that reflects light (make some turds shine, too! why not?!)