Quantum Mechanics
Why does the observer affect the wave function?
I think we first need to ask: What is an observer? What is an observation?
When we look at an object, what does it actually mean to look? To observe is to interact. Therefore, being an observer means interacting with the object being observed. Every observation or measurement is an interaction.
If that is true, then when we observe or measure something, we also become part of the system we are observing. The act of measurement modifies the object because we are interacting with it. We affect the object, and the object affects us.
This leads to an interesting paradox: Who is the real observer? Am I observing the object, or is the object, through its interaction with me, also observing me?
Perhaps the answer is neither. The moment I observe, I also become part of what is being observed. Reality is not defined solely by the observer or the observed, but by the interaction between the two. It is within that interaction that what we call reality emerges.