When can scientific laws be modified or changed?

Scientific laws can be modified or changed when new evidence emerges that contradicts existing understanding or when they fail to accurately describe observations in certain conditions. Advances in technology and methodology often reveal phenomena that were previously unexplained, prompting a reevaluation of established laws. Additionally, if a law is found to be too simplistic or not universally applicable, it may be refined or replaced by a more comprehensive theory. This iterative process is fundamental to the advancement of scientific knowledge.