Whether it is a flat mirror or a non-flat mirror (concave mirror or convex mirror), light will obey the law of reflection and be reflected by the flat mirror, and the reflected light can form vision in the retina after entering the eyes. On a flat mirror, when a parallel beam touches the mirror, the whole body will change direction in a parallel mode, and the image will be the same as that seen by the eyes.

In science, mirrors are also commonly used in telescopes, lasers, industrial instruments and other instruments. Metal devices with regular reflective surfaces and glass or metal products with metal reflective films are often inlaid with metal, plastic or wooden frames.

But in experiments, thin glass plates are often used instead of flat mirrors. Because the flat mirror is replaced by the glass plate, although the image is not as clear as the flat mirror, the image of candle A can be observed at the same time, which skillfully solves the problem of determining the position and size of the image.

To see more clearly? Mirror? The object in front of the glass should be as bright as possible and the environment should be as dark as possible. The objects behind the glass don't need illumination, and the environment is as dark as possible. Therefore, the plane mirror imaging experiment is suitable for dark environment.

The plane mirror can change the propagation path of light, but it cannot change the beam properties, that is, when the incident light is a parallel beam or a divergent beam, it is still a parallel beam and a divergent beam after reflection. Two rays emitted arbitrarily by an object enter the eyes after being reflected by a plane mirror. The human eye sees the intersection of the two lines along the opposite extension lines of these two lines.

That is, the image seen in the plane mirror, but there is no object behind the plane mirror, so the object becomes a virtual image in the plane mirror; The image distance is equal to the object distance, their connecting lines are perpendicular to the mirror surface, and their distances to the mirror surface are equal, up and down are the same, and left and right are opposite. This is a virtual image of the same size.

Mirrors will not have a cosmetic effect. Everything in the mirror must be the same as the real thing. Only the angle of light is different, the intensity of light is different, and sunlight has different colors. Noon is different from morning, evening is different from noon, and the reflection in the mirror is different.