กระจกเงา

Also known as looking glass

thumb|A mirror reflecting the image of a vase thumb|A first-surface mirror coated with aluminium and enhanced with [[dielectric coatings. The angle of the incident light (represented by both the light in the mirror and the shadow behind it) exactly matches the angle of reflection (the reflected light shining on the table).]] thumb|-tall acoustic mirror near Kilnsea Grange, East Yorkshire, UK, from [[World War I. The mirror magnified the sound of approaching enemy Zeppelins for a microphone placed at the focal point. Sound waves are much longer than light waves, thus the object produces di