Written by Michele Wheat
Have you ever wondered what makes things glow in the dark? With so many cool items that glow, from stars on your ceiling to glow sticks at a concert, you might be surprised to know that there's some real science behind it. Each item you own that glows uses a special process that helps to create its awesome glowing effect. You've probably had some fun with glow sticks at Halloween or worn a wristband during an event that helped to light up the night. This amazing glow is due to a scientific process called luminescence. Even some animals have these properties and glow in the dark.
What Makes Things Glow?
Luminescence is what causes items to glow brightly when it's dark. Unlike charcoal, wood, or paper, which can all give off light when they burn hot, things that use luminescence emit light without needing heat. When you have something like a toy that glows in the dark, it can glow because it contains materials called phosphors. Phosphors can radiate light after they have gotten energy from the sun or another source of bright light. The phosphors soak up the energy from the light, and then they radiate this energy as light.
Luminescence comes in several different forms, including chemiluminescence, radioluminescence, phosphorescence, and bioluminescence. Each type of luminescence is created in a different way. Phosphorescence is the kind of luminescence that uses phosphors to make something glow in the dark. Some examples of this type of luminescence include items like a computer screen and white LED lights. Chemiluminescence makes things glow by creating a chemical reaction. The electrons within the object become excited because of the reaction between two chemicals, and the electrons give off energy by glowing. Glow sticks are a good example of this process, since they require you to mix the chemicals inside to make the stick light up.
You likely won't see many things sold at the store using radioluminescence, but it is another form of luminescence that can cause things to glow. This type of luminescence refers to items that glow due to nuclear radiation. One of the coolest forms of luminescence is called bioluminescence, which refers to living things that glow in the dark. These creatures have an internal process that causes a chemical reaction and creates a bright light. Some examples of animals that use bioluminescence include fireflies, some species of deep-sea fish, jellyfish, certain algae, and even a few species of plants like mushrooms.
What Are Common Things That Glow in the Dark?
There are lots of amazing things you can buy that glow in the dark. Some of these items include:
- A wristband you might wear at a parade or a concert
- Stick-on stars and other shapes for your room
- Glow sticks
If you're curious about things that glow in the dark and want to play around with glowing things and learn more about how they work, check out these amazing resources.