Luftglans

Luftglans is a visual phenomenon that can occur under specific atmospheric conditions. It is characterized by a shimmering or glistening appearance of objects seen through the air. This effect is not a property of the objects themselves but rather a result of how light interacts with variations in air density.

These variations in air density are typically caused by differences in temperature. When air of different temperatures mixes, it creates layers with slightly different refractive indices. As light rays pass through these layers, they are bent or refracted at slightly different angles. This constant, uneven bending of light causes the image of the object to appear to shift and waver, creating the sensation of shimmering or glistening.

Luftglans is most commonly observed on hot days, particularly over surfaces that absorb and radiate heat, such as asphalt roads or sandy deserts. The heat rising from these surfaces creates convection currents of air with varying temperatures. Airplane pilots may also experience luftglans, as it can distort their view of the runway during takeoff and landing. While sometimes mistaken for heat haze, which is a broader term for atmospheric distortions caused by heat, luftglans specifically refers to the shimmering visual effect. It is a natural optical illusion produced by the Earth's atmosphere.