X-Message-Number: 17003
From: 
Date: Tue, 17 Jul 2001 02:35:46 EDT
Subject: More fire fly results...

Cryonet:

Results from experiments outlined in my previous post on the fire fly 
experiments (post #16965; 7/12/2001) are as follows:

* The fire fly frozen in a standard kitchen freezer with its ampoule full of 
water did not glow at all ever on retrieval, not even after the ice melted.  
I did not check to see if sectioning the abdomen would have worked.

* The similarly prepared fire fly (with water) in liquid nitrogen did not 
glow either.

* A fire fly who's lid (on the ampoule) was intentionally left loose such 
that LN2 might seep in to replace some air, did glow.  It did not however 
seem to demonstrate the earlier described initial "black out" before its 
sustained glowing  I was unable to determine how much LN2 replacement had 
occurred, while there certainly was some.  I would categorize this test as 
"inconclusive" as there were too many variables including the likelihood of 
the fly being partially submerged in LN2 as well as a back and forth 
"washing" on removal creating greatly differing temperatures and uneven 
thawing.  A better experiment will be to drill numerous tiny holes in such an 
ampoule with a fine drill bit (which will be very easy to do) or to use the 
sock method previously cited.

* While fire flies frozen with water or submerged in LN2 with water never 
glowed at all on retrieval, I did find that the fly from the experiment 
described above continued to glow when submerged in water--until I got tired 
of watching it.  I believe it would have done the entire 90 minutes.  This 
tends to rule out the previously described potentiality of oxygen usage by 
passive diffusion from the flies abdomen area.

I had planned to do a couple other experiments including placing a fly back 
in LN2 after it had been retrieved and was glowing to retrieve it again after 
a few minutes to see what effect there may have been.  Would it have 
continued to glow or would the "double whammy" disable the reaction?  I was 
also going to put such a glowing fly from the LN2 into the freezer in its 
open ampoule with the "outside temperature lead" of a standard indoor/outdoor 
thermometer inserted in with the fly to see when and how (i.e., what 
temperatures) and if the glowing ceased--and then remove it and see if it 
would resume.

Early on the problem was that two ampouled flies came loose from their 
mountings and are now floating at the bottom of the dewar.  Well, that fairly 
well guarantees that a couple of flies will get a several month long trial 
because I do not believe I am going to attempt to remove them for quite a 
while as I recently filled the tank to the top. In fact, it was the filling 
of the tank with LN2 that likely knocked the ampoules loose from their 
bindings on the string.

I may do a few more with enough specimens for each experiment to get a decent 
level of confidence in the reliability of each experiment.  We will see.

Sorry.  Kind of unfulfilling this time around.  As some great early American 
writer one penned: "Such is the nature with the best laid plans of mice and 
flies" (or something kind of like that).

Regards,

David C. Johnson, Raleigh

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