Moire, << mwah RAY or maw RAY, >> pattern is a pattern of lines formed when two regularly spaced patterns overlap but are not aligned. The word moire comes from the name of a ribbed fabric made since the 1400’s. Overlapping pieces of silk or window screens often produce moire patterns. Many optical art, or op art, paintings also have moire patterns. The patterns create an illusion of shimmer, as though some hidden feature of the paintings were vibrating. Scientists use moire patterns to detect abnormalities in surfaces and motions, because any change in a moire pattern is highly magnified.
