[Greenbuilding] Beer bottles as modular building materials (was re: Block Wall Insulation)

[Lance Collins]

Rob wrote:


>On a somewhat related note, (having a vague recollection that Heiny
>bottles might be green-hued) I have memories of something being written
>(also from Dinosaur Days) that green painted absorption plates on solar
>hot water panels were as effective or more effective than black painted
>ones, which according to the writer, didn't surprise him at all since
>Nature chose green as the colour for her solar collectors (leaves).

It's not often that Rob writes something so wrong!  Leaves are green 
because chlorophyll rejects green light.   The physics behind this 
are pretty difficult (the wikipedia entry needs some work).  It's 
something to do with a single sort of molecule being only able to 
capture photons in a narrow frequency range. Chlorophyll responds to 
photons in the yellow band and not green.

As to absorption plates 'black' in physics is not quite the same as 
'black' in 'black paint'.  I still recall an experiment in my first 
high school science class (also Dinosaur days) where a matt aluminium 
surface absorbed more heat than the same material painted black.  The 
reflected spectrum you see is not a good indication of the absorption 
spectrum of a surface.

Lance


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