We dont know! But that's one of the best things about it... we dont limit ourselves for fear of our lack of power in our universe... there's an infinite amount of things we dont understand, and we dont have any control over it, and no way to convince it, or communicate with it, but that's whats so amazing. By simply saying the theory is wrong and attempt to ignore it, we shut ourselves off from future discovery, and get stuck in an endless cycle where we dont make any improvements. If we hadn't investigated bacteria, instead following what people believed was just gods punishment, many more of us would be dying today