Abstract: This article aims to reinterpret the hidden principle and mechanism of the double-slit experiment in a more comprehensible manner, and to demonstrate a new perspective that better clarifies existent phenomena. This new perspective involves conducting the observation and analysis at a relative angle, which can partially reconcile the divergence between the quantum theory and the relativity theory. Several concepts are redefined from a relative viewpoint. In the proposed interpretation, the wave–particle duality observed in typical double-slit experiments gives only a surface appearance of certainty. The non-locality hidden in special relativity theory, which can also be found from a relative viewpoint, can subsequently be used to ...