Brr. It's cold out.
OK, so it's not all that cold here, but I came up with this idea when it was, forgot what I was going to post the minute I came on HB, and just now recalled it.
In cold weather, the window presents a double-edged sword. (Obviously a sharp one, since it's made of glass...)
If I open the curtains, blinds, storm panes, or whatever else is there to let the sparse sunlight flow in to warm my house, I also will increase the circulation of air around the windows, thereby allowing convection to present my warm house air to the cold windows, and increase heat loss that way. Yet, if I do not open the curtains, etc. the solar radiation stops at one of these obstructions, and fails to beam itself into my home, thereby reducing warming.
Oh, if only there were a way to... TWO! There are two ways! If only there was a way to get that light down to the floor without moving the curtains... and there is.
1: We may adapt traditional periscope technology to the window. Using a system of mirrors cleverly built into an easily placed boxy device that rests on the floor, and extends under the curtains to fit on the window sill. This portiscope reflects the sunlight that normally would enter the window down below the curtains, and radiates it out onto the floor. (Careful manipulation of this system may also allow it to function somewhat like a camera obscura projector, but we haven't got the kinks worked out of that yet.) Your sunbeam is now on the floor, heating the room as it should, even with a closed curtain.
2: Fiberoptic material (Oh no, I see the MFD tags at the ready now!) is woven into the fabric of a matching set of curtains and rugs. On the window-most side of the curtain, these fiberoptics stick out, and can collect the sunlight. The fiberoptics are then bunched together at the outer corner of the curtain, where they form a braided cable. This cable extends into the rug, where the ends again are spread out across the material, thereby allowing the sunlight to be collected evenly from the curtain, and deposited evenly in the carpet.
*Due to complaints of stabbing pain in the feet of our curtain and carpet users, the fiberoptic curtain design has been recalled. Our materials engineers are feverishly working out a new design that will be safer.