Re: Uses of Bulk Nano Materials (was beanstalks)
From: Sander Vesik (sander_at_haldjas.folklore.ee)
Date: 06/17/04
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Date: Thu, 17 Jun 2004 10:10:39 +0000 (UTC)
In sci.space.policy Keith F. Lynch <kfl@keithlynch.net> wrote:
> Henry Spencer <henry@spsystems.net> wrote:
> > In that context, you do need a wavelength that will penetrate
> > atmosphere.
>
> > Note that it's perfectly possible to build eye-safe lasers that will
> > do so. At wavelengths longer than (if memory serves) about 1400nm,
> > the eyeball is essentially opaque, so you no longer get that nasty
> > focused spot on the retina. There's no problem in principle with
> > picking a wavelength that fits in one of the atmospheric transmission
> > "windows" beyond there. Unfortunately, (a) there's somewhat of a
> > shortage of good lasers at such wavelengths, and (b) I'm not sure
> > there are any good solar cells that far down either.
>
> Why not take the opposite approach: Ultraviolet rather than infrared?
i think you would have similar laser problem, probably also laser
efficency problems and I'm not sure any UV wavelength is "safe".
-- Sander +++ Out of cheese error +++
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