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Q & A: Can light get through an atom-size hole?

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Most recent answer: 05/26/2012
Q:
Can light get through a whole the size of an atom?
- Robert (age 57)
Kansas City, MO
A:
In one sense, hardly at all. Say you were to make a sheet of some metal, thick enough to block light. Then, maybe using a particle beam, you drill a hole in it just a few atoms in diameter. You wont notice any light getting through the hole. Light propagates very poorly through holes smaller than the wavelength of the light, and the wavelength of visible light  is several thousand times the size of an atom.

In another sense, yes. An atom in a high-energy state can fall down to a lower-energy state, emitting light. (That's precisely how certain lamps work.) The light starts out in an atom-sized region, and escapes.

Mike W.

(published on 05/26/2012)

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