2 packs of jelly (85 g each)
1 red laser pointer
1 empty plastic bottle + lid
1 UV LED (light emitting diode)
1 button battery
1 Berocca tablet*
*To find out where to get these supplies, click here
Experiment 1: Jelly Fibre Optics
Make your jelly
- Find a big flat-bottomed container that is at least 2.5 cm deep and can go in the refrigerator. This is your jelly mould.
- Add 1 packet (85 g) of jelly to your mould.
- Add 250 mL of boiling water to the dry jelly in your mould
- Stir until the contents of our mould are dissolved and uniform
- Let set in your refrigerator over night
Jelly fibre optics: The next morning, take the jelly out of your mould and cut it into strips with a sharp knife. Experiment with how you cut to get a smooth edge. Try not to break the jelly.
Lay your strip of jelly flat. Shine your red laser pointer into your jelly along its length. What do you see? Does the light bounce around inside your piece of edible fibre optics? Play with the angle your laser points – what happens? Bend your jelly – now what happens? Now, have a taste – yum!
Experiment 2: Glowing Jelly
Make your jelly
- You can make this jelly in clear container. We recommend a thin plastic cup. It makes eating the results easier!
- Add 250 mL of boiling water and 1 Berocca tablet to 1 packet (85 g) of jelly.
- Stir until all solids are dissolved and the solution is uniform.
- Pour into your mould(s) and let set in the refrigerator overnight.
Jelly fibre optics: The next morning, connect your UV LED to the button battery by making the legs of the LED straddle the battery. If it doesn’t turn on, flip the battery over and try again. Direct your UV LED towards your jelly. What happens? What if you use your red laser pointer?
The Berocca jelly absorbs UV light (high energy) and turns it into lower energy (visible) light. What happens if you put sunscreen on your container and then shine your red or UV light? What kind of light does sunscreen block?
Keen to know more: Try looking up fluorescence. And do your own experiments!! What else in your kitchen can make jelly glow (hint: try tonic water)? Never stop asking and answering questions!!
Real scientists tell other people what they have found, and discuss what it might mean. You can do this below. Enter what you found as text, photos or video. Chat with others doing this experiment. Compare results. Learn stuff!