Because the coating stops the UV light, it also keeps the bulbs from giving you cancer- unless that's what you want, in which case you use a tanning bulb with a different kind of coding. This process is called fluorescence and is the namesake of the bulbs. The white coating on the inside of the glass absorbs the ultraviolet light and re-emits it as more visible light. And the atoms then emit visible and ultraviolet light. Electrical current flows from one electrode to the other, and when the electrons that make up the current bump into mercury atoms in the gas, the energy of the collision makes the atoms get excited. Fluorescent bulbs are basically gas-filled tubes with electrodes at both ends. The chemistry of the halogen gas allows it to capture stray tungsten atoms that evaporated off the filament and shepherd them back to where they belong, which both prolongs the life of the filament as well as keeps the inside of the ball clean and clear. Halogen bulbs have the same tungsten metal filament as typical incandescent light bulbs, but they contain a little bit of halogen-based gas in the bulb, as well. Each one makes its own clever use of physics to achieve the life goal of a light bulb- converting electrical current into visible light. So the incandescent light bulb is 19th-century technology, and by now, there's a blinding array of electric lamps- halogen light bulbs, fluorescence, mercury and sodium vapor lamps, LEDs, and so on. Bare filament electric lamps were first demonstrated around 1800 by Humphry Davy, and the glass bulb was added later to keep oxygen away from the wire so it could glow for a long time without actually burning up. Just run a bunch of electrical current through a thin wire until it heats up enough to start glowing. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.From tech to household and wellness products. Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.
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