The "faith" of an atheist is not the same as the faith of a theist. You're conflating two different uses of the word. I have faith that there is no god in exactly the same way that I have faith that there is no Flying Spaghetti Monster, or that I have faith that Russel's teapot does not, in fact, exist. If you want to call that "faith," it's within the boundaries of English usage, but it's an entirely different faith than positive faith in a particular god. And you clearly have no clue about scientific evidence. The default position is we assume things do not exist unless we are presented with positive evidence to the contrary. It's the theists who have the burden of proof, not the atheists. To this point, the theists have failed spectacularly.