Come along with me on this next tour, as we explore the world of florescence. Today’s featured museum is the only one of its kind in the world: The Electric Ladyland Fluorescent Museum, in Amsterdam, Netherlands, is an interactive “participatory art” museum; visitors can get creatively involved in the artwork, see fluorescent minerals light up, and can have their eyes opened to just how many common objects around us fluoresce. When was the last time you looked through your vegetable drawer with a UV light? Tomatoes, lettuce, cucumbers, bell peppers, coconuts… they all emit UV light waves.
First, what is fluorescence? It is also known as “black-light” glow; in other words, it shows up under UV (ultraviolet) wavelengths. Man-made fluorescence differs from nature’s spectacles of bioluminescence in that the latter doesn’t require external light – it is generated by an internal chemical energy in the organism. There are also examples of fluorescence occurring in nature: Syenite, also known as yooperlite or sodalite-syenite, is not a common rock, but does appear all over the world in pockets; in fact, about 15% of all minerals fluoresce. Check out this link to see where syenite can be found near you. Take a UV torch (flash light), and hunt for them at night. They look like plain rocks under normal lighting conditions, but glow under UV. There are also animals that don’t have bioluminescence, but do glow under UV lights, such as scorpions. To watch a short video about hunting along Lake Michigan for yooperlites (these start at 8:00), and see a glowing spider (19:23), click here. At 18:43, you can also see an example of phosphorescence.
Phosphorescence is what we also know as “glow-in-the-dark” when it comes in a paint form. The emission of visible light persists after this substance has been exposed to a light source; it fades over time, but the light “charges” the phosphorescent material, such as stars on a child’s ceiling, and glows for a time. This is the paint you also see marking airplane’s escape routes (I hope you never need them!).
Radioluminescence is, as its ominous name implies, a result of the decaying of radioactive isotopes; when mixed with a radioluminescent phosphorous chemical, the decaying radiation particles agitate the phosphor into emitting visible light. Believe it or not, Radium paint was used for over 40 years on the faces of watches, compasses, and aircraft instruments; if you are in possession of your great-grandfather’s or grandfather’s glowing watch, you might want to reconsider that. Radium emits gamma rays… think “Incredible Hulk”. Joking aside, the reality was far grimmer: The episode of history that became known as the “Radium Girls” and the impact it had on industrial safety standards deserves an article all of its own. Shockingly, radioluminescent paint may still be used in specialised applications, such as diving watches.
I hope you enjoyed this short tour through all things glowing. What do you have around your house that either glows in the dark, or emits light under a UV light? If you don’t already have a UV torch (flash light), you can buy one fairly easily online. If you’re brave enough, take a tour of your home in the dark – UV is known to show up things that have perhaps been missed in your cleaning routine; they will show you what foods you eat that fluoresce; and you’ll most likely learn a few things along the way! Have fun!
Stephanie Huesler 