Hi, Some writers on quantum physics, especially on copenhagen interpretation, talk about waves as "real" before measurement/hitting the screen/disturbing. Electron, in nature, is nothing but a real physical wave. They say particle like appearence as normally collapsing of this wave function. Others are talking about this waves before measurement have no reality as we used to. It's a mathematical wave in hilbert space. And write "this waves before the measurement are not waves as we know. These are probability waves. I'm really confused. Are waves waves? or is it something else? If answer is second, then ı have to ask what's interfering with itself? Because interference occurs physically real... And it's said to have no definite position for electron before measurement, because it doesn't have any. Before measurement, there's a wave which locations spread space. I understand that but doesn't it have to be a real wave for this description? Thank's for answers.