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If a vibrating atom can produce light why can't an alternating current of electrons do the same?

EDIT: When I use the term "light" I mean all EMR

SlightlyCyborg
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2 Answers2

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Yes, alternating current will radiate electromagnetic waves. For example, in telecommunication, the transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the antenna radiates radio waves.

The usual "pick up" that we get from electric currents in the circuits in the walls of a building have a frequency of about one hundred cycles per second. If we increase the frequency to $500$ or $1000$ kilocycles ($1$ kilocycles = $1000$ cycles) per second, we are
"on the air", for this is the frequency range which is used for radio broadcasts. (of course it has nothing to do with the air! we can have radio broadcasts without any air.)$^{*}$

$*$Extracted from the Feynman's lectures on Physics-Volume one.

Sensebe
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    doggone, and here I was about to point out that an incandescent bulb produces light when stimulated w/ AC :-) – Carl Witthoft Mar 06 '14 at 18:47
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    @CarlWitthoft, that's not the same thing. Incandescence is black body radiation and has nothing to do with the fact that the current source is alternating. You can light up an incandescent bulb with DC too. –  Mar 06 '14 at 19:24
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    @dgh I know that -- hence the smiley in my comment. Sorry for not making it clear it was a "lateral thinking" joke, albeit lame. – Carl Witthoft Mar 06 '14 at 20:12
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Although GODPARTICLE gives a "valid" answer by concentrating on the electromagnetic properties of light and radio waves, I believe this question refers to the visible aspect of light. If this is the case, then the answer is that the comparison is not valid. The best analogy I can come up with is like asking, why can't a truck pass through the same slot a motorcycle can? The answer is, it can, if the truck is "reduced" to the same size as the motorcycle. Likewise, if an electron is made to vibrate at a visible light frequency, it would produce visible light!

Guill
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