How would you explain second law of thermodynamics in light of entropy change??

Question

anonymous · Answer

Why the sky is blue. Similarly, you can trust with complete certainty that the spontaneous movement of half the molecules of the air to one side of the room you now occupy will not occur, even though the molecules are moving randomly and independently. On the other hand, if we consider a box whose dimensions are only a few molecular diameters, then we would expect that the random and short-term displacement of the small number of particles it contains to one side of the box would occur quite frequently. This is, in fact, the cause of the blueness of the sky: random fluctuations in the air density over tiny volumes of space whose dimensions are comparable with the wavelength of light results in selective scattering of the shorter wavelengths, so that blue light is scattered out, leaving the red light for the enjoyment of sunset-watchers to the east.

anonymous · Answer

it's taken from this page(2nd law of therm.) - http://www.chem1.com/acad/webtext/thermeq/TE3.html

ujjwal · Answer

thanks for trying but my question was not "why is the sky blue?" @beknazar23

anonymous · Answer

An quick summary of the second law is: in any spontaneous process the total entropy of the universe increases.

ujjwal · Answer

can you explain 2nd law a bit more with reference to entropy change?