Speaker 1: I'm at, I'm null, I'm Ben, and we are stuff
Speaker 1: they don't want you to know. Each week we cover
Speaker 1: the latest and strangest in fringe science, government cover ups,
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Speaker 1: you get your podcasts. Welcome to brain Stuff from How
Speaker 1: Stuff Works. Hey, I'm Christian Seger, and this is brain Stuff.
Speaker 1: It's fair to say that light bulbs their revolutionary invention,
Speaker 1: and it's tough to imagine the modern world without them.
Speaker 1: But they're not perfect. Incandescent bulbs produce way more heat
Speaker 1: than they do light, and their successors, compact fluorescent lamps
Speaker 1: hereafter referred to as CFLs, Well, those have their own disadvantages.
Speaker 1: In office buildings around the world, the weird buzz of
Speaker 1: CFL is slowly driving people into madness. So what is
Speaker 1: going on with this weird noise? Anyhow, The buzz itself
Speaker 1: is a product of magnet restriction, but for that to
Speaker 1: make sense, we're going to need to look at how
Speaker 1: these things actually work. The central element in a CFL
Speaker 1: is a glass tube filled with an inert gas usually
Speaker 1: are gone and mercury. The inside of the tube is
Speaker 1: coated with a phosphor powder, which influences the ultimate color
Speaker 1: of the light. There are electrodes at either end of
Speaker 1: the tube and they're wired to an electrical circuit. And
Speaker 1: still with me. When you activate the lamp, a current
Speaker 1: moves through the electrodes. There's considerable voltage across the electrodes,
Speaker 1: so electrons move from one end of the tube to
Speaker 1: the other. This vaporizes the mercury, changing some of it
Speaker 1: from a liquid to a gas. As the electrons and
Speaker 1: other charged atoms move across the tube, some of them
Speaker 1: collide with gaseous mercury atoms. These visions excite the atoms,
Speaker 1: bumping the electrons up to higher energy levels, and when
Speaker 1: the electrons return to their original energy level, they release
Speaker 1: light photons. However, most of this is ultraviolet light. Before
Speaker 1: it becomes useful to us, it needs to be converted
Speaker 1: to visible light. This is where that phosphor powder comes in.
Speaker 1: The ultraviolet light causes phosphor to fluoresce or produce visible light.
Speaker 1: Manufacturers can change the color of visible light emitted by
Speaker 1: using different combinations of phosphors. Here's where it gets a
Speaker 1: little tricky. The current inside the tube has to be
Speaker 1: limited so that it doesn't rise precipitously and trip the
Speaker 1: local circuit breaker. Fluorescent lights use ballasts to keep the
Speaker 1: current in check. The original ballasts for fluorescent bulbs are
Speaker 1: electromagnetic devices similar to inductors. Imagine a bunch of wire
Speaker 1: wound around an iron core. A change in the flow
Speaker 1: of alternate currents through the inductor creates a magnetic field.
Speaker 1: This field also changes, creating a changing voltage in the wire,
Speaker 1: slowing the currents flow. So a ballast is useful because
Speaker 1: it prevents fluorescent lights from well blowing things up. Think
Speaker 1: of it like a break in a car, except well,
Speaker 1: I guess okay, it can stop small explosions. Breaks and
Speaker 1: cars can also stop small explosions. Never mind. The point
Speaker 1: is that the ballast can also make that buzzing noise
Speaker 1: through an effect called magnetostriction. This happens when the magnetic
Speaker 1: field produced by the ballast physically squeezes that iron core.
Speaker 1: In the United States, the light is operating at sixty hurts.
Speaker 1: Thanks to magnetostriction, the core can be squeezed and released
Speaker 1: at twice that rate. A hundred and twenty hurts, creating
Speaker 1: the buzz, known and often hated by office workers around
Speaker 1: the world. Now for the next question, how do you
Speaker 1: get rid of the buzz? Well, one of the simplest
Speaker 1: solutions can be to replace the bulb itself. If you
Speaker 1: have an older fluorescent light, you may want to replace
Speaker 1: the ballast, But keep in mind that if the device
Speaker 1: begins to fail again, the buzz is going to return.
Speaker 1: And that annoying buzz is not the only thing people
Speaker 1: hate about compact fluorescence. The odd colors can give people headaches,
Speaker 1: and the mercury inside can pose some serious health risks. Luckily,
Speaker 1: there's some good news. We're not stuck choosing between inefficient
Speaker 1: incandescent bulbs and humming fluorescent ones. Instead, we can use
Speaker 1: l E ED bulbs. L E D bulbs may well
Speaker 1: be the light bulbs of the future, but that's a
Speaker 1: story for a different thing. Check out the brain stuff
Speaker 1: channel on YouTube, and for more on this and thousands
Speaker 1: of other topics, visit how stuff works dot com.