They result from the decomposition of light as it passes through the pearl layers, which act as a prism. The layers break up the light the same way a raindrop does when light passes through it creating a rainbow. More.
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.