Long time forgotten

[JoJo]

 I remember reading a story about people in a very poor country using this method to light their windowless shack during daylight hours. I couldn't find it but here is the idea. 

https://i.pinimg.com/originals/7a/9d/73/7a9d7311ed59a47bb00f56ece565a274.jpg

[Jackalope]

Yes, those bottles work reasonably well. I've seen them in operation in a few places.  In places where they get monsoons, the bottles aren't real effective because of low, heavy cloud cover, and they're prone to leaks around them.   I usually try to bring small solar powered lights, because either there's no electricity, or the electricity is intermittent.

[Kbop]

did i ever mention i have a fondness for old sailing ships?  they often used a deck prism to pipe light below decks.  same idea new materials.  The coke bottle idea is cool but won't it turn green in a week or two?


https://www.flickr.com/photos/alohadave/51443015

http://www.youtube.com/watch?v=bLg-K97sWxA

[Jackalope]

That's why they put a little bleach in the water in the bottle.  The bleach keeps the algae from growing.

[Kbop]

cool, that would fix it.