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When the Hoover Dam was
completed in 1936,
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it created a huge source of
hydroelectric power
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and zapped a sleepy desert town to life:
Las Vegas, Nevada.
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With the power supply from the dam,
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Las Vegas soon exploded
with vibrant displays.
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The source of these dazzling lights was
electrified neon gas.
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There are two tricky obstacles
to making lighted signs
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out of this naturally clear,
odorless gas:
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capturing it and making it glow.
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French inventor Georges Claude came up
with techniques to do both.
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In 1902,
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he developed a way of liquefying and
separating specific gases from the air,
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producing neon on an industrial
scale for the first time.
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By 1910, he had come up with a way
to trap the gas in a glass tube
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with a special electrode at either end,
and neon lighting was born.
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In workshops like Claude's,
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artisans known as tube-benders
made neon signs by hand.
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The tube-benders heated small sections
of a long, hollow glass tube
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and quickly bent them into shape.
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After the glass cooled, they attached
electrodes to each end
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and removed the air with a vacuum pump.
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Then, they passed a high voltage
current through the tube
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to remove any impurities on the
inside of the glass.
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Finally, they pumped the neon gas in
and sealed off the electrodes.
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When a neon sign is turned on,
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the electric current causes some of
the neon atoms' electrons to accelerate
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and break free of their orbits, leaving
behind positively charged ions.
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As these free electrons rush from
one electrode to the other,
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they collide with more neon atoms,
causing them to ionize as well.
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When these excited electrons fall back
to their normal energy levels,
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their excess energy is carried away
by photons, or particles of light.
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All this happens in an instant,
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and the glow from the photons is what
we see when we switch on a neon sign.
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Though it's common to call any
gas-filled sign a "neon" sign,
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there are actually 5 different
gases used in production.
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Each gas emits photons of a different
wavelength when electrified,
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which correspond to different
colors of light.
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Neon gives off an orange-red glow, argon
glows a pale lavender,
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helium a dusty pink, krypton a silver-
white, and xenon a light purple.
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These 5 gases can be combined
with color-coated tubing
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to create an electrified rainbow of
text and images.
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Business owners soon realized how
effective these colorful beacons
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were for attracting customers.
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And unlike a light bulb, a neon sign has
no incandescent filaments to burn out,
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and can shine continuously for 40 years
before the gas depletes.
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By the 1930s, neon signs were lighting
up storefronts all over the world.
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Because of the glass tubes'
fragile nature,
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it usually wasn't feasible to ship
them over long distances.
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Instead, most neon signs were created by
local neon shops
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and then installed nearby.
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Signs with humor, personality, and
intricate designs proliferated,
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no two exactly alike.
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But by the end of World War II,
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plastics had become widely
available and inexpensive,
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and plastic signs supplanted neon
as messengers of modernity.
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Many towns removed neon signs they
viewed as old-fashioned.
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Today, neon sign production is only
a fraction of what it was at its peak,
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but the craft of tube bending lives
on relatively unchanged.
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New creations hand-crafted
by local artisans
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join survivors from the heyday of neon,
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hiding in plain sight in city streets
around the world.