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Glow in the dark envelopes

mummymonkey

Did you spill my pint?
mummymonkey
Joined
Dec 3, 2002
Messages
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Location
Scotland
What causes the violet light you get when you open a self adhesive envelope in the dark?

Noticed this today when I opened an envelope in the gloomy front hall. It only works on some, so it must be a propety of a particular kind of adhesive I assume.
 
Where does the light come from? Stamps and pre-printed envelopes have phosphor or fluorescent inks for use by the sorting machines.
 
Nick Bogaerts said:
Where does the light come from? Stamps and pre-printed envelopes have phosphor or fluorescent inks for use by the sorting machines.
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There is a momentary purple light emited from the seperation point as you pull the two glued surfaces of the envelope apart.
 
mummymonkey said:
There is a momentary purple light emited from the seperation point as you pull the two glued surfaces of the envelope apart.
Click to expand...
Can't remember the specifics, but you can get the same when you crush a suger cube. And, i believe, in earthquakes....
 
I believe the sugar cube is from piezoelectricity - the tendency of some crystals to generate a voltage when compressed.

I don't believe this would explain the envelopes. My guess - it was licked closed by a reptiod from Planet X.
 
Ryan O'Dine said:
I believe the sugar cube is from piezoelectricity - the tendency of some crystals to generate a voltage when compressed.

I don't believe this would explain the envelopes. My guess - it was licked closed by a reptiod from Planet X.
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Yeah, that's the thing, and i believe it is the same with the envolope, atleast i think Discovery Channel told me that.. But then again, Discovery Channel told me that aliens were living in the US and liked strawberry icecream.... i **** you not.
 
This is interesting.

Now, if only we could figure out how to power our cars using self-sealed envelopes. :)

Do you suppose God allows some of this wild and crazy stuff, like half the stuff we debate around here, just to keep man from being bored while being on earth? That there is more to life than sleeping, eating, shelter and that other thing that we do to occupy our time? :)

Then again, someone might be laughing, knowing they are going to cause millions of people to take envelopes into a dark room and try this. Could be a conspiracy by the Company making envelopes. Maybe the Mead company is behind this. :)
 
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This reminds me of a "puzzler" that began every chapter in my physics book in college. The particular puzzler referred to the spark that occurs when chewing a wintergreen Life-Saver.

Here is the explanation of the effect.

"The graininess of electricity is responsible for the blue glow that is emitted by a wintergreen Life-Saver while it is being crushed. When the sugar (sucrose) crystals in the candy rupture, one part of each ruptured crystal has excess electrons while the other part has excess positive ions. (A positive ion is an atom or molecule that has lost one or more electrons.) Almost immediately, electrons and positive ions jump across the gap of the rupture to neutralize the two sides. During the jumps, the electrons and positive ions collide with nitrogen molecules in the air that is then flowing into the gap.

The collisions cause the nitrogen to emit ultraviolet light that you cannot see and blue light that is too dim to see. Oil of wintergreen in the crystals absorbs the ultraviolet light and immediately emits enough blue light to light up a mouth or a pair of pliers. However, if the candy is wet with saliva, the demonstration fails, because the conducting saliva neutralized the two parts of a fracture crystal before sparking can occur."
 
I found a german webpage referring to this phenomenon. It looks like this:
http://www.kopfball.de/filme/img/040425_a_01.jpg

I try to translate the explaination:
These envelopes use a syntetic glue. When you close the envelope, electrons travel from one surface to the other. You end up having two areas with two different electric charges.
If you open the envelope you tear these two charges apart and end up with an electric field between them. The electrons "want to equalise" the charge and by doing so, they hit nitrogen molecules in the air which get charged by them. As soon as they loose this charge again, they emmtt light.

Please don't ask me anything about this, I just tried too translate... ;)

FR

ETA: It's apparently called "tribolumeniscence"
http://en.wikipedia.org/wiki/Triboluminescence
 
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You can also get the same effect with Breathe-Right nasal strip packages. Occasionally I find I need to put one on after having been in bed for a while, so I open it in the dim light. I'm almost always surprised by the light show.

Then I rub my cat on the wool blanket for some real fireworks. From the blanket, I mean.
 
apocalypse said:
This reminds me of a "puzzler" that began every chapter in my physics book in college. The particular puzzler referred to the spark that occurs when chewing a wintergreen Life-Saver.

Here is the explanation of the effect.

"The graininess of electricity is responsible for the blue glow that is emitted by a wintergreen Life-Saver while it is being crushed. When the sugar (sucrose) crystals in the candy rupture, one part of each ruptured crystal has excess electrons while the other part has excess positive ions. (A positive ion is an atom or molecule that has lost one or more electrons.) Almost immediately, electrons and positive ions jump across the gap of the rupture to neutralize the two sides. During the jumps, the electrons and positive ions collide with nitrogen molecules in the air that is then flowing into the gap.

The collisions cause the nitrogen to emit ultraviolet light that you cannot see and blue light that is too dim to see. Oil of wintergreen in the crystals absorbs the ultraviolet light and immediately emits enough blue light to light up a mouth or a pair of pliers. However, if the candy is wet with saliva, the demonstration fails, because the conducting saliva neutralized the two parts of a fracture crystal before sparking can occur."
Click to expand...

What then might happen if one chewed on these AND pop rocks at the same time with a mouthful of metal fillings? Can you imagine. It could be like the Fourth of July...and the person might even hear songs by John Phillip Sousa.
 
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