Can that which is observed be the observer? This results in a contradiction, because it entails another observer to observe the observer. Thus the import of this rationale declares that the observer cannot be observed, it cannot be made an object of. Therefore, nothing which is empirical can be the observer --- this includes states of mind, personal identity, beliefs desires and the physical world right down to its subatomic constituency. This is what Krishna declares to be the field of knowledge, not the knower. The knower cannot be known empirically ---- rather we are the knower and we must realise the knower.
So what is this that is called quantum? This in Hinduism is known as Mula-prakriti, it is the original state of matter before it collapses into an object state. It is the field within which the whole universe takes forms. It is this field which becomes the mind-field and within which all forms take place. Nothing really exists, there is no outside or inside, everything takes place within the mind-field itself. All thoughts-waves that arise within the mind-field take to us an appearance of an objective form. The reason that the interaction between subjective and object occurs is because they are both modifications in the form of thought waves which occur within the mind field. The field and the knower of the field are not the same though, they are interdependent entities, their mutual co-dependence is logically necessary for their to be existence. Thus quantum which is the nature of the field is indicative of the knower, but knowing the field cannot lead to knowing the knower.