Many natural phenomena cannot be explained if Earth were flat, including the observation that the bottom part of a distant object appears clipped. To “explain” it as if it can occur on a flat Earth, flat-Earthers invented the “explanation” that it is due to what they call “perspective.”

This supposed “perspective” that flat Earthers invented is different from the actual law of perspective. To distinguish it from the actual, real-world law of perspective, many people call it “flerspective,” a combination of the words flerf and perspective.


Under the “law” of flerspective, the bottom part of a distant object can appear clipped on its own, despite there is a line-of-sight between the observer and the hidden portion. This assertion contradicts what we observe in the real world.

In the real world, perspective cannot cause an object to be half-visible and half-hidden. If there is a clear line of sight, the bottom part of the object will be visible. If not, then it is due to other reasons, like an obstruction by another object.

The “law” of flerspective does not have predictive power. It cannot be used to predict the visibility of a distant object qualitatively. We can try asking any flat-Earthers, and nobody will be able to calculate how far a distant object to start appearing hidden.

For the flerfs.

A surprising fun science fact is that the curve of the earth is detectable simply by standing up. This works best with the surface of the ocean or a large lake, and it's something you can easily do at the beach. I recently gave it a go in a visit to Venice Beach near Los Angeles. With my Nikon P900 I held it close to the water level (about two feet up) and took a photo of a boat off in the distance. I then stood up and took another photo:

Source: https://www.metabunk.org/threads/stand-up-to-detect-the-curve-of-the-earth.8364/

Just realised something hilarious, with all the flat earth chats I'm in, my evidence for the earth being a globe that I forward results in me getting banned or kicked most of the time.

Not one flat earther has been banned in this chat and they've all left on their own. Interesting right? It's like they're deliberately trying to block out the truth, the cold hard evidence...

The Lake Pontchartrain causeway and transmission lines demonstrate Earth’s curvature. Flat-Earthers attempt to dismiss it using aerial photos where it is more difficult to see the curved landmarks over water.

On the other hand, from these alternative vantage points, it becomes easier to reveal the horizontal curvature by magnifying vertically. Because of the possibility of lens distortions, some of the images are inadequate evidence of the curve. However, all of them are insufficient evidence of a flat Earth.

Evidence that the horizon doesn't rise to eye level.

Many different map projections are created to preserve different properties of the sphere-like body at the expense of other properties. Some of the resulting distortions are acceptable, and others are not. A projection type can be suitable for a purpose but not for others.

Flat-Earthers claim the so-called ‘flat-Earth map’ is distortion-free and use it as proof of its correctness. In reality, a map can only be distortion-free if the actual shape it represents is also flat. There are many ways we can use to show that the “flat Earth map” is, in fact, distorted.

Every map of the Earth has distortions due to the fact it is a two-dimensional representation of a three-dimensional object. It does not mean a distortion-free representation of the real Earth does not exist: we call it a globe.

Usually, the tourist trap operator will guide the unsuspecting tourists to a sink supposedly placed directly on the Equator. They will then release the plug and show that the water does not form a vortex. Afterward, they will show a sink north of the Equator and another south of the Equator and demonstrate that the water spirals in a different direction.

In reality, this is only a parlor trick. These people make the water spin in a different direction by how they pour the water. Pouring the water to the right of the drain will make the water spin counterclockwise and vice-versa. Furthermore, when the water drains without spinning, it is because the water is already in the sink. They let the water sit for some time before unplugging the sink.

Scientists have been debunking this myth for some time. For example, Alistair Fraser from PSU debunked this myth in 2003 or earlier, far before the birth of the modern flat Earth craze in the late 2010s.

The myth began from an experiment by Ascher Shapiro from MIT, where he demonstrated that the Coriolis effect can be observed in a bathtub-sized tank. This is, however, an experiment done in a very carefully controlled environment, very different from our everyday bathtub.