If you’ve ever seen objects under a blacklight – like clothes or highlighters – you may have noticed that some things glow when they’re hit by that kind of light, and others don’t. The things that are glowing are fluorescing! Fluorescence in this case is caused by an interaction between high energy UV light (from the blacklight) and some of the electrons in that object. When that high energy light strikes the object, those electrons are able to absorb the energy from the light for a short period of time. However, the electrons soon let go of that energy, emitting it as a slightly lower energy light. The light that they release is the glowing that we see!
Today at Astrocamp, we wanted to see if we could make fluorescent soap-bubbles. It not only worked, but also turned out to be pretty easy and something you can do at home! We’ll show what we did, step by step, so that you might be able to recreate this experiment yourself!
Making the Fluorescent bubble mixture:
- Bubble Solution. We made our own with dish soap and water. If starting with bubble solution, skip steps 1 & 3!
- Fluorescent Highlighters. Yellow tends to work best!
- Bubble Wand
- A knife or scissors
First, add a bit of dish-soap so a container. We used a small styrofoam bowl, but you can use whatever you like.. A tablespoon of soap should be enough, but you may need more depending on the amount of water you add later.
Second, carefully cut the back-end off of a highlighter and remove the inkpad. You will need an adult for this part! Then do your best to squeeze as much highlighter-ink as you can into the bowl. In our experiment, we used a yellow highlighter. To cut our highlighter, we used a pair of scissors. For brighter bubbles, add more ink to your mixture by removing the inkpad from more highlighters! You will probably get a bunch of ink on your hands. Don’t worry! It is non-toxic, and will make you look very cool with the blacklight!
Finish up your bubble mixture by adding water. Your bubble mixture should appear still appear “soapy” after adding water. If you think you added too much water, add more soap!
Lastly, to make the mixture fluoresce, you’ll need a black light and a dark room. To make the bubbles, you’ll need a bubble wand. If your bubbles aren’t working well, add more soap or water. If they aren’t very bright, you can add more highlighter. One was enough for this video, but your blacklight may not be as bright.
What you’re seeing
When you’re blowing your bubbles and seeing them glow under the blacklight, you’re seeing fluorescence! The electrons from the atoms in the highlighter-ink are absorbing the high-energy, invisible UV light from the blacklight and emitting it as a slightly lower energy light that we can see – as a bright glowing.