In physics, the observer effect is the phenomenon where the act of observation or measurement disturbs the system being observed. This occurs because measurement is not a passive process; it requires an interaction between the instrument and the system, which inevitably alters the system's state.

Key Characteristics:

• Interaction is Fundamental: To measure a property, one must exchange energy or information with the object. For example, to "see" an electron, a photon must bounce off it. This collision transfers momentum to the electron, changing its path and velocity.

• Classical Examples: The effect exists in macroscopic physics. Measuring the air pressure in a tire requires releasing some air to operate the gauge, thereby changing the pressure. Similarly, a t ...