The "law of common fate" refers to the principle that objects or elements that move or act in a similar way are perceived as belonging together. Synonyms for this law could include the "principle of group motion" or the "unified movement theory." Other terms that convey a similar concept include the "principle of continuity," which refers to the tendency to perceive smooth and continuous lines or patterns as a single entity, and the "closure principle," which refers to the perception of incomplete shapes or patterns as complete. All of these terms relate to the way our brain processes visual information and organizes it into meaningful wholes.