[BC] Your friend, the Ionosphere

[Rik van Riel]

On Mon, 22 Oct 2007 08:33:33 -0700
Cowboy <curt at spam-o-matic.net> wrote:

>   How about blocking the deadly cosmic radiation that causes the
> existence of the layers in the first place ?

The ionosphere only holds out radiation on the frequencies that
it reflects RF. That is, from 100kHz to about 10-70MHz depending
on conditions.

The dangerous radiation is ultraviolet and up.  That radiation
gets blocked by the ozone layer and other gasses in the atmosphere.