As far as the bullshit debunked Post,
Fata Morgana mirages significantly distort the object or objects on which they are based, often such that the object is completely unrecognizable. A Fata Morgana may be seen on land or at sea, in polar regions, or in deserts. It may involve almost any kind of distant object, including boats, islands, and the coastline.
Often, a Fata Morgana changes rapidly. The mirage comprises several inverted (upside down) and erect (right side up) images that are stacked on top of one another. Fata Morgana mirages also show alternating compressed and stretched zones.
[1]
The
optical phenomenon occurs because rays of light are bent when they pass through air layers of different temperatures in a steep
thermal inversion where an
atmospheric ducthas formed.
[1] (A thermal inversion is an atmospheric condition where warmer air exists in a well-defined layer above a layer of significantly cooler air. This temperature inversion is the opposite of what is normally the case; air is usually warmer close to the surface, and cooler higher up.)
In calm weather, a layer of significantly warmer air may rest over colder dense air, forming an atmospheric duct that acts like a refracting
lens, producing a series of both inverted and erect images. A Fata Morgana requires a duct to be present; thermal inversion alone is not enough to produce this kind of mirage. While a thermal inversion often takes place without there being an atmospheric duct, an atmospheric duct cannot exist without there first being a thermal inversion.
The Optical and Air Inversion is then explained using Snell's Law,
This is the reason these things happen and why,
Snell's Law
Snell's law is used to determine the direction of light rays through refractive media with varying indices of refraction. The indices of refraction of the media, labeled
,
and so on, are used to represent the factor by which a light ray's speed decreases when traveling through a refractive medium, such as glass or water, as opposed to its velocity in a vacuum.
As light passes the border between media, depending upon the relative refractive indices of the two media, the light will either be refracted to a lesser angle, or a greater one. These angles are measured with respect to the
normal line, represented perpendicular to the boundary. In the case of light traveling from air into water, light would be refracted towards the normal line, because the light is slowed down in water; light traveling from water to air would refract away from the normal line.
Refraction between two surfaces is also referred to as
reversible because if all conditions were identical, the angles would be the same for light propagating in the opposite direction.
Snell's law is generally true only for isotropic or specular media (such as
glass). In
anisotropic media such as some
crystals,
birefringence may split the refracted ray into two rays, the
ordinary or
o-ray which follows Snell's law, and the other
extraordinary or
e-ray which may not be co-planar with the incident ray.
Fata Morgana is the short answer, why it happens is Snell's Law,
If you pay attention, they explain it is usually short-lived, which is what we see in shooting, it's caused by the layers of hot and cold air mixing which changes our perception of the image to do the change in medium. That change causes the light to change speed hence we see it wrong.
