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Speaker 1: Welcome to Brainstuff from house stuff works dot com where

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Speaker 1: smart happens. Hi Am Marshall Brain with today's question, what

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Speaker 1: is the difference between a fluorescent light and a neon light?

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Speaker 1: A neon light is the sort of light you see

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Speaker 1: used in advertising signs. These signs are made of long,

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Speaker 1: narrow glass tubes, and these tubes are often bent into

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Speaker 1: all sorts of shapes. The tube of a neon light

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Speaker 1: can spell out a word, for example. These tubes emit

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Speaker 1: light in different colors. A fluorescent light, on the other hand,

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Speaker 1: is most often a long, straight tube that produces white light.

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Speaker 1: You see fluorescent lights and offices, stores, and some home fixtures.

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Speaker 1: The idea behind a neon light is simple. Inside the

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Speaker 1: glass tube, there is a gas like neon, argon or

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Speaker 1: crypton at low pressure. At both ends of the tube,

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Speaker 1: there are a metal electrodes. When you apply high voltage

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Speaker 1: to the electrodes, the neon gas ionizes and electrons flow

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Speaker 1: through the gas. These electrons excite the neon atoms and

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Speaker 1: cause them to emit light that we see. Neon emits

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Speaker 1: red light when energized in this way. Other gases emit

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Speaker 1: other colors. A fluorescent light works on a similar idea,

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Speaker 1: but it has an extra step. Inside a fluorescent light

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Speaker 1: is low pressure mercury vapor. When ionized, mercury vapor emits

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Speaker 1: ultraviolet light. Human eyes are not sensitive to ultraviolet light,

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Speaker 1: although human skin is. That's how we get sunburns and

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Speaker 1: sun tans. Therefore, the inside of a fluorescent light is

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Speaker 1: coated with a phosphor. A phosphor is a substance that

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Speaker 1: can accept energy in one form and emit energy in

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Speaker 1: the form of visible light. In a fluorescent lamp, the

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Speaker 1: phosphor accepts the energy of ultra violet photons and emits

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Speaker 1: visible photons. The light we see from a fluorescent tube

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Speaker 1: is the light given off by this phosphor that coats

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Speaker 1: the inside of the tube. The light of a neon

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Speaker 1: tube is the colored light that the neon adams give

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Speaker 1: off directly. Do you have any ideas or suggestions for

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Speaker 1: this podcast? If so, please send me an email at

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Speaker 1: podcast at how stuff works dot com. For more on

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Speaker 1: this and thousands of other topics, go to how stuff

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Speaker 1: works dot com and be sure to check out the

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Speaker 1: brain stuff blog on the how stuff works dot com

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Speaker 1: home page.