Meta-comment: I know that the question is trivial and this isn't a physics discussion board, but still am surprised by the number of downvotes. I am interested in the voters' reasons. Is it OK to ask for an advice concerning diet, headaches or car purchase, but not physics? Why is that?

Notice: The post has been at -5 at one moment, the comment reflects that state. If its long-term karma is positive or zero, the implicit hypothesis in my question - i.e. that people are downvoting questions about physics more than questions about headaches - may not be true.