The question of whether the collapse of the wave function requires an observer is a topic of ongoing debate and interpretation in quantum mechanics. The traditional interpretation of quantum mechanics, known as the Copenhagen interpretation, suggests that the act of measurement by an observer causes the collapse of the wave function.
However, other interpretations, such as the Many-Worlds interpretation and the consistent histories interpretation, propose alternative explanations that do not require a conscious observer. These interpretations suggest that the wave function evolves continuously and that the apparent collapse of the wave function is a result of the interaction between the system being observed and its environment.
In recent years, experiments and theoretical investigations in quantum information theory have shed light on the nature of quantum measurement and the role of observation. Quantum information is indeed preserved within a system even if we do not make an observation. The information encoded in the quantum state can be carried by entanglement with other systems, and it can potentially be accessed or inferred through subsequent measurements or interactions.
It's important to note that the interpretation of quantum mechanics is a matter of philosophical and scientific debate, and there is currently no consensus on a definitive interpretation. Different interpretations provide different conceptual frameworks for understanding and describing quantum phenomena. The question of the role of observation and the collapse of the wave function is still an area of active research and exploration in quantum foundations.