Flerfraction

Atmospheric refraction generally raises the apparent position of astronomical objects near the horizon, as well as causing a slight vertical compression

Atmospheric Refraction is the bending of light within Earth's atmosphere due to variations in air density. Flerfs generally have no clue how atmospheric refraction actually works, so they use it (flerfraction) to explain phenomena which are actually impossible on a flat Earth, such as:

• sunsets and moonsets
• why stars can't be seen from particular locations (e.g. Polaris from the southern hemisphere)
• why the horizon appears below eye level
• the existence of the south celestial pole.
• why the sun and moon do not change in angular size
• star trails always being perfectly circular

Not all flerfs use flerfraction to explain the above phenomena; those who don't generally invoke flerfspective.

Flerfs often deny the presence of refraction when presenting observations of "missing curvature", while simultaneously using it to explain observations that are impossible on flat Earth. This is an example of the Third Law of Flerf.

Atmospheric "Magnification"

Many flerfs claim the atmosphere can magnify things like a magnifying glass. This is partly because they think the term "atmospheric lensing" (which generally means the same thing as atmospheric refraction) literally means the atmosphere acts like a bioconvex lens. Flerfs use this to explain why objects can appear obstructed by the horizon.

Walter Bislin's Flat Earth Dome Model

Flerfs have plagiarised Walter Bislin's Flat Earth Dome Model, claiming it is a working model of flat Earth. In reality, the simulation shows how light would need to bend in impossible ways for flat Earth to make any sense. Flerfs that subscribe to this model believe the light bending is made possible due to flerfraction and/or some firmament-related magic.