From your error message it seems like $latitude and $longitude does not contain any values. You probably want to check that $start is properly set. This is all I can help you with since I do not know what $start is and how you're getting it.
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.