Thanks for the warm welcomming. And as an added bonus, I still have all my ranking stars. Silence is golden, as usual...
Sorry for the brevity, but I am still swimming in it thick until the end of this month. Anyway, folks, feel free to email me to take it where we left it, and I will get to it sooner or later.
jjw, the issue that is puzzling you has nothing to do with the size of the photon, neither as what we commonly percive as size, nor with the wavelength.
The answer to your question is simply kmown as the intensity law. The intensity of light (i.e. the number of photons per unit time) incident on a transversal surface varies with the inverse squared distance to th4e surface (neglecting scattering and absorption).I~I0/r^2, where I0 is the intensity of the source. Replace intensity with the photon rate, and you got your answer.
If you want to see where this law comes from, there is a nice way to do it. Take a piece of paper, and in its center draw a small blob. that is your source. Take a protractor, and now from your blob draw outwardly every say, 5 degrees, straight lines. Those are your photons emitted by the source. Now, using the blob as the center, take a compass (geometrical copmpass and not a navigational one) and draw concentric circles with radii 1 cm, 2cm, 3cm, 4cm, etc. If you use a letter sized paper, you should get quite a few such concentric circles.
Here is where your imagination must come into place. Imagine these circles as the intersection of concentric spheres with the plane of your paper, and now you have a source of light illuminating the space.
Take now your 1cm radius circle, and chose an arbitrary semicircle out of it. Count how many lines go through this semicircle. If you drew the lines every 5 degrees, you will have 36 lines going through this semicircle.
Now, the length of the semicircle is pi*1cm=3.14 cm. On each of the remaining concentric circles (of increasing radius) measure a length along the circumference equal to 3.14cm, and count how many lines go through this length for each of the circles. Plot the number of lines through this portion of the circumference as a function of the radius, and as a function of the inverse squared radius. Let me know what you get.
Hope this helps.
Cheers.
