Effective use of natural sunlight in a habitat.

--- In spacesettlers, "Ian Woollard" wrote:

> On 24/07/07, Xenophile wrote:

>> And remember, I was suggesting using mostly infrared for cooking,
>> with a little red thrown in to indicate when the fibers are "on."

> Yes, I used to work with Infrared that's what's used for
> telecommunications; it's worse because you can't see it, so it
> doesn't trigger the blink reflex, while still destroying your retina
> just fine. I think the red would be a waste of time, you'd never see
> it because the infrared would destroy that bit of the retina that
> the red and infrared would both shine upon so quickly.

Well if it's enclosed and used to heat a hob, like you suggested, this
shouldn't come up. I'd be happy to use green or yellow or purple, if
that's better.

>> Also, I'm not talking lasers, just so there's no confusion.

> You are, because there's NO optical way to turn ~1kW/m^2 into
> 8MW/m^2 using mirrors or lenses; there's an optics theorem that
> states that.

I'm not sure we're on the same page. When the Israelis shove 8 watts
down a millimetre fiber, they aren't using lasers. They use mirrors.

||At the heart of their experimental system is a parabolic mirror that
measures about 8 inches in diameter. The dish-shaped mirror collects
sunlight and concentrates the beams onto a small flat mirror suspended
above the center of the dish.

The flat mirror reflects the concentrated light energy into a
1-millimeter wide fiber optic cable, which can carry the light up to
100 meters away with very little loss of energy. At the other end of
the fiber optic cable, the light can be directed onto any target -
against a cancerous section of a patient's kidney, for example.||

http://www.israel21c.org/bin/en.jsp?enDispWho=Articles%5El205&enPage=BlankPage&enDisplay=view&enDispWhat=object&enVersion=0&enZone=Health&

> In this case they would be using sunlight to pump up a lasing
> material; that's where the IR comes from.

I was thinking a prism to separate the different colors. And again,
I've got nothing against using it to heat a fob.