已知天空是蓝色的，请推导出“阿伏加德罗常数”?

看看这里面。据说是爱因斯坦干的：

Original by Philip Gibbs May 1997.

Why is the sky blue?
A clear cloudless day-time sky is blue because molecules in the air scatter
blue light from the sun more than they scatter red light. When we look
towards the sun at sunset, we see red and orange colours because the blue
light has been scattered out and away from the line of sight.

The white light from the sun is a mixture of all colours of the rainbow.
This was demonstrated by Isaac Newton, who used a prism to separate the
different colours and so form a spectrum. The colours of light are
distinguished by their different wavelengths. The visible part of the
spectrum ranges from red light with a wavelength of about 720 nm, to violet
with a wavelength of about 380 nm, with orange, yellow, green, blue and
indigo between. The three different types of colour receptors in the retina
of the human eye respond most st