[TML] Alien ecologies

[Bruce Johnson]

On Aug 28, 2008, at 5:14 PM, Jerry W Barrington wrote:

> On 8/28/08 5:42 AM, "Robert O'Connor" <robocon at ozemail.com.au> wrote:
>
>> Jerry Barrington wrote:
>>> No, it is not.  Did you look at the link I mentioned for  
>>> chlorophyll's
>>> absorption spectra?
>>
>> No. I used graphs like these:
>> http://www.mbari.org/staff/ryjo/cosmos/Cabs.gif
>> http://upload.wikimedia.org/wikipedia/commons/4/4c/Solar_Spectrum.png
>
> The chlorophyll one looks near enough like the one in the wiki.  So  
> I took
> your 2 pics and scaled them the the same scale on the wavelengths,  
> and put
> them in 1 pic.
>
> <http://www.geocities.com/jursamaj/MergedGraphs.png>
>
> Remember that the height of the solar spectrum has been squished by  
> a factor
> of 10.55, so differences are way more then this makes clear.  Note  
> the the
> blue peak of chlorophyll a (the most common form, considered  
> "universal") is
> well down from the peak of sunlight, by about 30-38%.

That's because the absorbtion peak does not depend on the protein  
(which can change via evolution) but the captive metal atoms chemistry  
(which cannot)



-- 
Bruce Johnson
University of Arizona
College of Pharmacy
Information Technology Group

Institutions do not have opinions, merely customs