In reply to David Roberson's message of Sun, 14 Apr 2013 18:37:33 -0400 (EDT): Hi, [snip] >I have always been suspicious of why a photon of light interacts with only one >electron when the wavelength of the light is many times larger than the atom >that contains that electron in orbit. Why is there little response from the >nearby atoms that have resonances at the same frequency?
The difference in angular momentum for an electron for allowed transitions is always h_bar, and a photon only has 1 h_bar to give, so only 1 electron can absorb it. (I'm just dying for someone to contradict me here! :) > > >One might be able to raise an argument concerning reciprocal behavior to >explain why only one atom responds to the incoming photon. In this case, only >a single photon is released by the change in orbital of a single electron. >Why the enormous size question arises is beyond my understanding. I don't see the size as a problem, do you? > > >A low frequency waveform such at the ones we are discussing can be polarized >in any dimension right angled to the forward travel path and is not typically >helical when man made. You can generally find a null direction to either the >electric field or magnetic field of the traveling wave. The antennae that we make are typically either vertical or horizontal, and as such generate either vertically or horizontally polarized waves. You can view a polarized wave as a slinky that has been squashed flat. IOW the axis of the coils of the helix is perpendicular to the direction of travel, whereas for a circularly polarized beam, it lies along the direction of travel. (Slinky not squashed.) (Once again, I would love to be shown to be wrong here. I would learn something new. :) Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
