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Light up your night with a little sugar.
Dr Yan uses some very sweet science to make sugar glow in the dark.
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Join Dr Yan in lighting up the dark with just a little sugar.
| Difficulty: medium | Make the room really dark (and practise crushing sugar cubes beforehand) |
| Time/effort: low | Once you've finessed the sugar-cube-crush, you're sweet to go |
| Hazard level: low | Careful when crushing the sugar - gentle gentle! |
SAFETY: Be careful when crushing the sugar cubes with a glass - especially in the pitch black. Adults might want to supervise young children.
Some white sugar cubes
Loose sugar
A flat bottomed glass
A white plate
Crush a sugar cube with a flat-bottomed glass.
Wait for it to get dark outside.
Practise sitting in the room with the lights out and letting your eyes adjust.
Place a few sugar cubes on a white plate.
Sprinkle some loose sugar onto the same plate.
Take a glass and have a practise crushing the cubes and the loose sugar.
Now do it with the lights off!
Triboluminescence from crushing sugar.
You should see flashes of luminous blue light.
Your eyes need to be adjusted to the darkness in order to really see these lights. So, try and wait until night-time to give this a go. Practise sitting in a room with the lights out so your eyes are able to adjust. If your room doesn't get dark enough, climb under a duvet and have another go.
If you're just using loose sugar, try and find some with large crystals. Demerara worked for us.
If this method really doesn't light up your life, then read further down and see what else you can try.
There's a variety of ways triboluminescence can work.
A light stretch:
Take a brand new rubber band and in a very dark room (maybe even under a duvet) stretch it. The whole band should, very briefly, glow.
Sealed with a glow:
Take a self-sealable envelope and seal it. Then rip the seal open. You should see sparkles of light as the seal comes apart.
Pulling duct tape apart may produce light.
The duct tape challenge:
This one is particularly difficult but if you're on a luminescent roll then give it a go! Take a roll of duct tape and tear off a long strip. Fold the strip in half, leaving enough tape at the top to fold over (see image) so they can be ripped apart. Turn the lights off - and rip. If you're very lucky you just might see a line of blue light as the tape is torn.
The glowing blue lights that we can see from this experiment are part of the science of triboluminescence. It sounds complicated, but it really just means 'rubbing light, which is what it is: the light you see when you tear, crush or rub certain materials.
Dr Yan's demonstration involved the crushing of sugar. The act of crushing sugar involves energy and it seems that some of that energy is being converted into light. It is thought that this is probably because the splitting/ripping of materials causes a separation of positive and negative charges.
As you might know, opposite charges attract. So the mere act of separating them takes a fair amount of energy. Scientists think that when these charges shoot back together again, some of that energy used to separate them is converted into visible light. Believe it or not, beyond that very little is known or understood about triboluminescence. All the more reason to keep practising it and see what else you can uncover!
The Uncompahgre Ute Indians from Central Colorado were one of the first people in the world known to use tribolunminescence, due to the lights they created from quartz crystals. The Ute made ceremonial rattles from buffalo rawhide filled with clear quartz crystals. When the rattles were shaken at night during ceremonies, light would flash through the buffalo hide.
Finley from Huddersfield wrote an 'Ask Yan' about this very subject. Read the answer here.
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