[Rockhounds] colour perception, organic fluorescence, etc

[Jim Daly]

In those weather conditions (I assume it was pretty cold) I'm surprised the fungi glowed very strongly. Makes me suspect the mechanism for foxfire isn't the same as Cyalume.
When the Cyalume lightsticks were first developed all sales people for American Cyananid were issued a bunch of them to hand out to customers, since it was a product in search of a market. Our sales person for New England, on a cold and snowy night got stuck in a snowbank. She had no flashlight, so she grabbed some lightsticks from the trunk. When she cracked it to activate it-- nothing! Seems that the rate of the light-producing reaction is strongly affected by temperature ( as are most chemical reactions). 
If the foxfire reaction isn't dependent on temperature, I don't know what it is!
Jim

--- On Sat, 12/13/08, J. R. Hodel <jr50wv at yahoo.com> wrote:

From: J. R. Hodel <jr50wv at yahoo.com>
Subject: Re: [Rockhounds] colour perception, organic fluorescence, etc
To: sauktown1 at yahoo.com, rockhounds at lists.drizzle.com
Date: Saturday, December 13, 2008, 2:10 PM

Hi Jim,

Years ago a cousin and I were - not lost, just temporarily misplaced, and wound
up walking a long way around in the woods of Raleigh county, WV, the Friday
after Thanksgiving (late November, into early wintery weather for those not
familiar with USA weather patterns) and we got out of the woods onto a country
road around 10 pm, after 3 or 4 hours in the woods after dark, in sleety
weather.  My cousin was from the city, and pretty upset, but I kept him with
me, and we made it out of the woods OK, following the "go downstream"
rule.

I noticed in the middle of that walk in nearly pitch dark some glowing
fragments on the ground, and called my cousin over.  We picked up some
fragments of a stump, and wondered over the glowing dim green light.

There are a lot of "fireflies" in WV too, little bugs that fly and
blink in the early evening, one sex is glowworms in the grassy lawns, the other
blinks in species-based patterns.  I understand that there's one species of
glowworm that is carnivorous, and blinks fake signals of other species to lure
in and eat lovelorn fireflies.  So sad!

JR in WV  

--- On Sat, 12/13/08, Jim Daly <sauktown1 at yahoo.com> wrote:
From: Jim Daly <sauktown1 at yahoo.com>
Subject: Re: [Rockhounds] colour perception, organic fluorescence, etc
To: jr50wv at yahoo.com
Date: Saturday, December 13, 2008, 10:41 AM

There's also phosphorescence of organic compounds in the woods at night.
Fungi that glow a light blue grow on dead and rotting tree trunks. In the east
we called it "foxfire".
This is very likely the same mechanism as the firefly's light and the
synthetic equivalentof the Cyalume light sticks.
UV fluorescence is probably the same mechanism- just a different activation
wavelength.
Jim Daly

Axel, here in the North American forests we have several woods that fluoresce
under the right stimulation.  Locust (I think the black locust variety native
to the WV forest) glows, as does the shrub sumac.  This isn't the poison
sumac which I think is a western shrub, this is a shrub which bears bright red
fruit clusters with which you can make a pleasent non-intoxicating beverage. 
It glows best in long-wave "black light".  I don't remember
which
spectrum locust responds to best.

Do we know what mechanism might cause the fluorescent reaction in organic
materials?

Just wondering, sorry if we're off topic, but it is related to black light,
etc.

Merry Christmas, everyone!

JR





--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
 
 text/html
---
--
_______________________________________________
Rockhounds at drizzle Mailing List
Subscription Services:
http://lists.drizzle.com/mailman/listinfo/rockhounds
List Home Page, with a link to the List Usage Policy:
http://www.eclecticlapidary.com/Rockhounds/index.html



      




--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
---
--
_______________________________________________
Rockhounds at drizzle Mailing List
Subscription Services:
http://lists.drizzle.com/mailman/listinfo/rockhounds
List Home Page, with a link to the List Usage Policy:
http://www.eclecticlapidary.com/Rockhounds/index.html



      

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
---