speed of light


by benzun_1999
Tags: light, speed
mormonator_rm
mormonator_rm is offline
#19
Dec30-03, 10:53 PM
P: 209
If you leave light alone it acts very clearly as a wave, as in diffraction and interference experiments. But as soon as you do something to detect or deflect it, it makes a decided choice on its quantum state, and acts like a particle. This is clearly demonstrated in diffraction experiments where the photons passing through a grating trigger a detector; resulting in the total breakdown of the diffraction pattern (as if it were no longer a wave).
Adrian Baker
Adrian Baker is offline
#20
Dec31-03, 07:38 AM
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P: 419
Originally posted by mormonator_rm
If you leave light alone it acts very clearly as a wave
Your example is a good one, but the wording quoted above is a little imprecise. For example, the Photoelectric effect can ONLY be explained by considering light as a particle. It does not need to be 'left alone' to do this.
It is perhaps best to say that light can ACT like a particle, or like a wave but is neither.

Benzun_1999 - if this leaves you asking, "How is it possible to visualise this?" then join the queue with the rest of us.......
mormonator_rm
mormonator_rm is offline
#21
Dec31-03, 05:28 PM
P: 209
"Detected or deflected". If a photon is deflected, then it is clearly NOT left alone (though the experimenter has done nothing directly, an interaction has). "Deflected" includes the Photoelectric effect. If a photon strikes something, such as an electron on the surface of a metal, then it is forced to chose a quantum state, and hence act as a particle. Until it strikes the object, though, it is still in wonderful wavefunction limbo-land.


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