The paint in this spray can, when released from the container, immediately oxidizes in the air via an exothermic reaction to (temporarily) produce visible light. The effect eventually fades, as the paint dries invisibly, leaving no trace in daylight, or evermore.

The paint or ink could also be used in pens for writing (much smaller) ephemeral messages in the dark.

Useful for one-night communiqués, potential nocturnal trysts in back alleys or whatnot.
-- nihilo, May 18 2006

Chemiluminescence http://www.lumigen....chemexplained.shtml
Chemical light without heat [nihilo, May 18 2006, last modified May 20 2006]

I think you mean Exothermic reaction. The process would give off both light and heat. The chemicals would have to mix as they spray from the can, forcing the reaction. If they were premixed in the can you'd obviously have the reaction going on inside, and the pressure would heighten the reaction, and spray cans have to be pressurized anyway.
-- kuupuuluu, May 18 2006


Whoops. I didn't earn a "D" in O Chem for nothin'.

But this particular reaction releases energy primarily electromagnetically, rather than thermally. The precise reaction to be utilized remains to be specified.
-- nihilo, May 18 2006


Which makes it...magic.
-- normzone, May 18 2006


It's not magic. Chemical reactions that produce light and not heat are well known. See link.
-- nihilo, May 18 2006


I prefer "witchcraftiness."
-- nihilo, May 18 2006


//this particular reaction releases energy primarily electromagneticall//

Why? Wouldn't a thermal release be just as effective, or am I missing your point?

Even so, the idea is nice [+]. The spray could be utilized by motorway/transport/ emergency services as a temporary safety measure at night.
-- kuupuuluu, May 18 2006


No sense in losing valuable chemical energy through heat. There isn't any need to either; just look at glow worms.

And the product would be ideally suited to precisely some sort of motorway/transport utilization. That's probably just one of its many potential uses.
-- nihilo, May 18 2006


temporary glow in the dark grafiti. Cool. i think you could use the same reaction as is used in glow sticks, just mix the chemicals in the spray head and you get a few hours of light. They are already non toxic and i believe non staining, though they may be water soluable which could be good or bad depending on the application.
-- jhomrighaus, May 18 2006


those glowsticks stain, and only pretend to be non-toxic. they burn when they touch skin.
-- tcarson, May 26 2006



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