Explain the scientific causes of under eye dark circles.?

The official cause is genetic (although some skin irritants may cause a temporary black mark).

Simply put its due to poor circulation of blood in that area. I'm sure other will have better detailed answer.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.