The question of whether the past is set in stone or subject to change is a philosophical and metaphysical inquiry into the nature of time and causality. It raises questions about the ontological status of past events and the possibility of altering or revising the past. In classical and commonsense views of time, the past is often considered as fixed and unchangeable, a sequence of events that have already occurred and are beyond our control. However, some philosophical discussions challenge this perspective. In the realm of theoretical physics, certain interpretations of quantum mechanics propose that the past may not be as immutable as it seems. The phenomenon of quantum entanglement and the delayed-choice experiment suggest that the outcomes of past measurements can be influenced by future choices, leading to questions about retrocausality. Philosophers also explore the malleability of the past in the context of time travel scenarios and thought experiments. The question of whether the past can be altered or whether it is definitively set in stone remains a subject of philosophical debate, metaphysical exploration, and scientific inquiry.