When we refer to “modern physics” we mean the physics of the 20th century, which has changed the framework of our way of thinking, partly.
It was the relativity theory, but more so quantum physics to prove that the reality of our world doesn’t exist until there is an observer. Thereby we have to question the separation of spirit and matter as well as the problem of subject and object. This marks an exciting discovery as the logic of Aristotle, the either-or logic, is also put to the test, now.
To summarize: The fundamental result of quantum physics:
In quantum mechanics the properties of an object are not determined until a measurement made. Therefore the strict separation of “subject” and “object” in the cognitive process has vanished.
However, this should not be over-interpreted. The observing physicist with his emotions and wishes is excluded in the quantum physics as much as in classic physics. Only the idea of a reality, which exists regardless of “observation” and which by being “observed” will be pictured truly in all its properties had to be given up. I have put “observation” in quotation marks, as there is no need of a human observer required. Matter particles can “observe” each other mutually and thereby take over the role of “subject” in subject-object splitting. This appears only in so far absurd, because by the use of the word “matter particle” we presuppose that there is a separation between matter and spirit. We displace all spiritual aspects and are in an unresolved contradiction, when we describe to matter particles aspects of a “subject”.
By the way 5 of the most important physicists who received the Nobel prize for their contributions to quantum physics: (Max Planck, Albert Einstein, Max von Laue, Louis de Broglie and Erwin Schrödinger) turned against the findings of their own science.. The discomfort with the disappearance of the strict separation of subject-object was too great. The former existence of a reality regardless of observation was the successful requirement for the cognitive process of classic physics.
Einstein said: “Would that mean, that physics only describes what you imagine but not what really exists?”
Einstein’s attitude expresses the primal fears, which appear, when realism – the construct of reality as an image of something that actually exists – is not certain any more. Then fear shows up, that my I- identity is dissolved or my I-identity is getting lost.
Due to the radical statement of quantum physics that observation produces reality, some physicist tried to integrate the consciousness of the observer into quantum physics. Wolfgang Pauli objected to that: “At the moment when the physical observer has chosen his experimental setup, he no longer has any influence on the result of the measurement, which objectively registered is general accessible present. Subjective properties of the observer or his psychic condition do not influence the natural laws of quantum physics any more than they did in classic physics.“
Meanwhile quantum physics is the most proven theory in physics we have ever had – in regard to accuracy of the match between theoretical prediction and experimental result.