I first heard about this on the radio during Halloween and finally looked into it.
Believe it or not, this jello is “glowing”. The reason you can’t see the glow is because there is too much normal or visible light.
Now the science. Technically the jello is not glowing in the dark. The term is fluorescence.
Fluorescence means that the object is reflecting back visible light when it is hit with ultraviolet light (UV). It takes light we can’t see and gives back light we can see.
All florescent objects “glow” in the light. We just can’t see it because of all the visible light….(We get a little of the glowing effect which is why fluorescent orange and green is so easy to spot from a distance.) If we use a “black light” you really see what is going on. A black light gives off about the same amount of UV light as any light bulb but very little visible light so the effects of the UV light can be seen.
How do you get the jello to glow? Use tonic water instead of normal water.
Tonic water contains quinine which is a fluorescent molecule.
What are other uses of quinine? You may have heard about it being used as a treatment for malaria. Better meds are being used today, but for many years it was the only treatment for the disease. History of Quinine
Quinine has a bitter taste and some that were taking quinine water would mix it with gin. A mixture that is still popular today.
Never tasted it? The jello I made tasted like it was mixed with old grapefruit juice that left an aftertaste. It is now out in the corn field where I doubt if any creature will consume it.
More tonic water treats…
I tried to freeze it for glowing ice cubes.
The tonic water did not freeze well. Still slushy even after over night.
By the way, I was also disappointed by the lack of glow with my jello. Why….
Perhaps the yellow jello is interfering with the bluish light. In the fridge now is a batch of BLUE TONIC JELLO.