[Rockhounds] colour perception, organic fluorescence, etc

[Kitty & Bill Heacox]

Axel Emmermann wrote:
> I think it may be related
> to peripheral vision and after -images (suppose you're driving a car on a
> coast way while the person in the passenger seat is wearing red. Sea is on
> your left. After a short time the blue of the sea may cause your left eye to
> see a slightly yellow overtone while the red sweater causes you right eye to
> see a litter greener. Just a theory)
>   
_RE color perception:_
When I was in college (half a century ago) there was a party with a 
theme from "The Wizard of Oz" where all the lights in the room were 
green, to suggest the Emerald City.  When we left the party the whole 
visible world seemed bathed in red for several minutes.   Then another 
group put on a party at Christmas where the tree and all the lights in 
the room were red, and of course when we left everything appeared green.

Movie directors use this "hunger" of the eyes for the complementary 
color to direct the viewers' attentions to important people or items.  I 
recall in one of Alfred Hitchock's movies he wanted us to notice Grace 
Kelly entering a large room full of people without making it obvious.  
So he staged the room in warm colors and had all the people costumed in 
the same (red, brown, orange, dark yellow).  Grace Kelly entered far in 
the background and to one side, slowly and with lots of people around so 
that she was only gradually revealed;  the camera remained steady and 
did not zoom in on her, and she did the opposite of a Grand Entrance:  
she kept her eyes down or looking away from the camera.  But she was 
dressed in green and our "green-starved" eyes picked her up right away.  
It made us want to whisper to our hero (maybe Cary Grant): "Look over 
there!  See that woman---no, wait, someone stepped in front of 
her...there she is! Can't you see her?"

You can test this by holding a small red card on a white or gray 
background and staring at it for several seconds, then remove the card 
and you will see the image of the card in green and vice versa.  Same 
with orange and blue, or yellow and purple, though red and green is most 
obvious.

_RE organic fluorescence:_
I know much petrified wood is fluorescent.  Is this related to the 
organic origins of the wood? 

And I recall seeing some kind of fungus that glowed in the dark in the 
woods in New Jersey when I was a child, and this was without a UV lamp.

And I think we discussed some years ago on this List the white glow 
sometimes seen in ocean water.  Some have said that this coincides with 
a "Red Tide" of algae bloom, but I have seen it on two occasions when 
there was no coloration in the water.  I think it still is some kind of 
ocean mini-critter, but perhaps not the "Red Tide" stuff.  The effect is 
called "Phosphorescent," but that would seem a misnomer to me, at least 
compared to phosphorescence in minerals.  One time I saw it in Puget 
Sound when my family was digging for clams, especially the one 
pronounced "/gooey-duck/" and is variously spelled geoduck, goeduck, 
goiduck, or gweduck. (I like "geoduck" best;  it looks like it has 
something to do with rocks!)  Anyway, we went out to the beach in the 
dark, and when we shoved a spade into the sand it sparkled and flashed 
white for several seconds.  As you tossed a spadeful of sand aside it 
glowed as it hit the sand.  Our footprints glowed as we walked.  The 
second time was when Bill and I were camping at Manele Bay on the island 
of Lanai (this was before the luxury Four Seasons Manele Bay Resort  
resort was built there).  We watched ocean waves crash making white glow 
and spray, and then a glistening sheet of white was left in the sand as 
the waves receded.  At first Bill thought it was just moonlight 
reflected off the water, but then a cloud came over to darken the moon, 
and the glow showed even brighter.  I can't be positive that there was 
no red in the water on either of these occasions because they occurred 
at night.  But there was no sign of red the day before or after, and no 
reporst from residents.  But red or not, I assume it was cause by some 
microorganism.

Aloha, Kitty