Black+Lights

I think the black light was a very important and useful invention. Have you ever seen a black light? Have you ever wondered "Why is my white shirt glowing" while standing under one? I have some questions of my own. What causes things to glow in the presence of a black light? What use, practical or not, do they have? Why were they invented and by who, and what the heck is black light anyway? Well I think they are an important (not to mention fun) part of modern life. But before I explain how they are in any way useful in our world, I think we should first know what exactly black light really is. In order to understand black light, we need to know about the magical thing we call the Electromagnetic spectrum. What the Electromagnetic Spectrum tells us is the wavelengths of the various types of electromagnetic radiation. Radio waves are first in the spectrum because they have the longest wavelength. This means that the size of the radio waves is larger than that of any kind of EM radiation with a smaller wavelength. Radio waves are used for, you guessed it, Radio and T.V. transmissions. The next type of EM radiation is microwaves, and yes, these are the same kind of microwaves that reheat your food in a microwave oven. Microwaves have the second largest wavelength in the spectrum. Did you know that microwaves are used in the Wi-Fi system? No joke. Next up is Infrared radiation. This is just below red in the visible spectrum of light hence the name infrared. I believe this is used in security systems with the trip lasers. After infrared radiation we have the visible light spectrum which, believe it or not, is actually electromagnetic radiation. The colors have different wavelengths and above infrared is regular visible red. Then the colors go in the order of the rainbow until we get to violet which has the shortest wavelength in the visible spectrum. This means anything above violet or below red is invisible to us humans. Then above violet we get something I'm sure you've heard of, Ultraviolet radiation. There are three types of UV radiation: UVa UVb and UVc. UVa is the safest of the three with the wavelength closest to visible light, with UVc being the most dangerous. Black lights Are basically UV light producers and are of the UVa type. Now that we've finally gotten to black light on the EM spectrum I can tell you all how it works. We all probably know how black lights cause some objects to glow, But why do some things glow and why do other things not? It has something to do with these things scientists call phosphors. Black lights produce very little visible light as most of the light is released in the form of invisible UV light. When UV light come into contact with these phosphors the UV light is absorbed and released as visible light which makes the object appear to glow or as scientists say "fluoresce". This was and is used in many cool ways. Black lights were used as a way for fighter pilots to see the controls of his or her plane while not giving of visible white light to give him/her away to the enemy. The US dollar bill has an invisible strip that only appears under a black light and most commercial paper has phosphors added which makes discovering counterfeit money easier. Black lights are also used in medicine to help find and kill bacteria and other contaminants that could cause sickness. CSI agents use black lights to check a crime scene and dust for fingerprints and look for other evidence. For example, most body fluids like saliva or sweat contain phosphors. A more practical use of black lights is in bowling alleys or laser tag arenas where they use special paint designed to glow when under black lights and make the place look cooler, or in a reptile exhibit for reasons I don't actually know to be honest.

With all these uses for black lights, the man who invented them must have had a reason to do so. Well there was a reason and that reason is actually listed above. The Man who Invented the black light was a man named Will Byler in 1935 while he was working at the general electric labs researching how electricity could be used to help cure disease. He invented the "Ultraviolet Black light Bulb" using Woods glass, invented 27 years prior by a man named Robert Will Wood, and called his new invention the "Woods Lamp". 5 yearslater he suggested the use of theses black lights for fighter pilots in WW2, as listed above.

Do we all agree that black lights are really cool and really useful? Good. Lets go through a brief overview of what we've learned today. We've learned what a black light is, how it works, who invented it and why and how they were and are used. I'd say thats a lot of learning in such a short time( It took me almost 6 days! ). Next time you see a black light, maybe now you'll take a sec to remember whats really going on and why the person next to you is glowing blue and think about what an amazing invention it is.