english: So to explain that -- if you've got an elementary particle and you shine a light on it, then the photon of light has momentum, which knocks the particle, so you don't know where it was before you looked at it.
non_english: Da objasnim - ako posmatrate elementarnu česticu i osvetlite je, foton te svetlosti ima impuls, koji "udara" česticu, tako da ne znate gde je tačno bila pre nego što ste je "pogledali".