Re: [SG,DS, Colonial] Invasive Species

On Fri, Feb 05, 1999 at 12:18:43PM +1300, Andrew & Alex wrote:
>     Actually, I was under the impression that anything that grows
_doesn't_
> need UV light. Which is why humans have melanin and why we burn under
> sunlight with UV in it. UV light tends to sterilise and destroy
organic
> molecules, like DNA and so on. Remember the hole in the ozone layer?
The
> ozone layer filters out UV light, except where the hole is.

	Well... the ozone layer doesn't get _all_ UV, and it only
works in a specific band. Some UV _is_ necessary for plants, and for
people. Isn't vitamin D formed in skin by UV light?

	Too much of a good thing is bad, but having none of it would
be worse. Planetary colonies in shirt-sleeve climates probably won't
have any problems, but colonies in pressurized environments will
probably have lots of flourescent lights to help with the _lack_
of natural UV.

-- 
						crawford@iac.net
"the feeling was exhilarating and addictive"
	-- Microsoft employee Vinod Valloppillil, on his first exposure
	to Linux development