## Pic Gaspard

The photo of Pic Gaspard taken from Pic de Finestrelles is one of the farthest line-of-sight photos of an object on Earth’s surface, taken from another location on Earth’s surface. It is possible to take the photo due to the height of the peaks & atmospheric refraction.

The apparent height of Pic Gaspard relative to the other peaks proves Earth is a sphere. If Earth were flat, Pic Gaspard should appear higher than Grand Ferrand from the observer’s location. Simulations also give us the same results as observation, confirming that it is really what would look like on a spherical Earth.

## Perspective and the Lake Pontchartrain Transmission Line

The Lake Pontchartrain power transmission pylons demonstrate Earth’s curvature. Flat-Earthers invented various excuses to dismiss the observation, including the excuse that it was just a perspective effect.

If it were just a perspective effect, the same parts of the pylons would line up in a straight line, converging into a distant point. In reality, they do not line up in a straight line but are visibly curving downward due to the curvature of the Earth.

## Forced Perspective

The Sun & the Moon are about the same apparent size, but they are not the same size. They only appear the same size because the Sun is 400× larger and also 400× farther away. To illustrate this, we can use forced perspective in photos.

Flat-Earthers insist that the Sun & Moon are the exact sizes just because they appear the same size. By the same ‘logic,’ we can say the girl above is the same size as the Eiffel Tower.

## Perspective Compression: Determining If a Curvature Exists

By utilizing perspective compression, it will be easier for us to observe the curvature of an object if the object is curved.

Flat-Earthers like to deliberately choose a vantage point where it is difficult to see Earth’s curvature, and they use it to “prove” the curvature does not exist. In reality, they only make it more difficult to see the curvature. It does not mean the curve is not there.

## True Horizon and Linear Perspective

In graphical, linear perspective, the horizon is the horizontal line where the vanishing points for level objects lie. However, as the Earth is a sphere, the horizon of linear perspective is not the same as the true horizon, which is the line that we observe separating Earth from the sky.

Flat-Earthers claim that the observed horizon is produced by the law of perspective. In reality, from a high vantage point, we can try extending level and parallel lines to find their vanishing points. In many cases, they will end up above the true horizon.

## Shadows in Photographs Taken on the Moon

Flat-Earthers and other conspiracy theorists incorrectly claim that the shadows in photos taken on the Moon in the Apollo missions are inconsistent. In reality, it is just due to their confirmation biases, and we can easily explain how the shadows were formed.

The perspective effect can cause parallel shadows to appear angled to each other and converge to a distant point. Conspiracy theorists incorrectly claim that non-parallel shadows can only be caused by a nearby light source.

## Flat Earth Dome Model

The “Flat Earth Dome Model” (walter.bislins.ch/FED) is an app created by a fellow flat Earth debunker, Walter Bislin. The app attempts to map observed reality to the flat Earth model. Lines in the app portray how light rays must have traveled if Earth were flat. They demonstrate that light must bend in a physically impossible way if Earth were flat, disproving a flat Earth.

Videos of the app are circulating in flat-Earth communities, and flat-Earthers fail to understand what the app is showing. They incorrectly assume the app “proves” a flat Earth when in reality, it thoroughly disproves the flat Earth model.

## Sky

The sky appears practically identical to all observers on Earth, except that the Earth obstructs the view to a different part of the sky to a different observer on Earth, and daylight obscures the view to most objects in the sky.

The fact that the sky appears identical everywhere on Earth can only be adequately explained if all the astronomical objects are very far from us and that the Earth is a sphere.

## Perspective of Earth Due to Different Observer Distance

Because of a perspective effect, an observer in space can see more of Earth’s surface if they are farther from Earth.

Flat-Earthers noticed the different visible Earth’s surface in different Earth images and used it to “prove” they are fake. In reality, it is just a perspective effect caused by the fact that the Earth was seen from a different observer distance.

## ISS Size Compared to an Airplane in a Photograph

Flat-Earthers compared the apparent size of the ISS and an airplane that appeared in photographs and then incorrectly concluded that the ISS could not be 410 km above us. Their mistake was equating altitude with distance and failing to account for both the ISS’ and the airplane’s downrange distance.

If an airplane is at an altitude of 12 km, it does not mean its distance from an observer is also 12 km. Its altitude and distance are equal only if the airplane is directly above the observer. If the plane is not directly above, then its distance is greater than its altitude.

## Curvature App

Curvature App is a web application we can use to create a simulation of the horizon’s shape and the visibility of distant objects on a flat and spherical Earth. Curvature App is available at walter.bislins.ch/Curve.

When determining a distant object’s visibility, flat-Earthers often use wrong calculators that fail to account for all the important variables and give them incorrect results. Curvature App accounts for all of these variables, and not only it gives us the numbers, but also the simulated view.

## Camera “Maximum Range”

There is no such thing as the “maximum range” in the specification of any camera. Just because a camera cannot see something at a certain distance, it does not mean it must not be able to see another thing farther away.

Flat-Earthers claim that the Moon cannot be 384400 km away because a camera cannot see another thing much closer than that. In reality, an object’s distance is not the only thing that determines if a camera can see it, but the object’s size also matters.

## Flerspective

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.

## Pictures of Earth’s Surface from the UAE Astronaut Hazza Al-Mansouri

The United Arab Emirates astronaut, Hazza Al Mansouri, took pictures of Earth’s features like the Nile and the Persian Gulf during his visit to the ISS. Flat-Earthers claim the pictures are fake because the various objects appear very large compared to the size of the Earth in the picture. The reason is that they do not understand that the ISS is only about 400 km above Earth’s surface, and only a very small amount of the Earth’s surface is visible from the ISS

## View of the Earth from the ISS

The International Space Station (ISS) is only about 400 km above the Earth’s surface, only 6% farther from the center of the Earth than the Earth’s surface. Therefore, only a very small part of Earth’s surface is visible from the ISS at any time.

Flat-Earthers like to examine photos of the Earth from the ISS and compare them to those taken from a much farther location. They would take any difference as an inconsistency. In reality, the ISS can only observe a very small part of the Earth, unlike spacecraft much farther away.

## Proportions

The Sun is 1,391,016 km (864337 mi) in diameter and 146,600,000 km (93,000,000 mi) from us. These facts are consistent with everyday observations.

Flat-Earthers have a different idea about the distance and the size of the Sun. However, on careful examinations, the numbers are inconsistent with everyday observations.

## Flat-Earth “Perspective” is not Real-World Perspective

To an observer, the law of perspective will cause objects moving away in a straight line to:

1. appear to approach the vanishing point but never quite reach it,
2. never appear to go across the vanishing point,
3. appear to shrink in size,
4. never appear to be cut in half unless when it is obstructed by another object.

If the Earth were flat, sunsets, sunrises, and other general phenomena where objects are not visible due to Earth’s curvature should not occur. To “fix the problem,” flat-Earthers invented the explanation that the apparent obstruction of a distant object can occur on a flat Earth due to “perspective.” Their “perspective” is simply a baseless ad-hoc explanation that does not resemble how the real-world perspective works.

## The Varying Earth-Moon Proportions in Different Pictures

How an object appears in a photograph depends on perspective —the position of the camera relative to the object—, and field of view of the camera. The farther the object, the smaller the object will appear in the resulting image; and conversely, the closer the object, the larger it will appear. The narrower the field of view, the larger the object will appear in the image; and conversely the wider the field of view, the smaller the object will appear.

Flat-Earthers take the varying proportions of the Earth & Moon in different pictures as a glaring inconsistency. They are wrong. The pictures were simply taken from a different perspective and field of view.

## The Apparent Size of the Moon

The apparent size of the Moon remains constant in a single day. This can only happen if the Moon is practically at the same distance all day.

In the flat-Earth model, the Moon is thought to be moving in a circle above the flat Earth. Such a notion should cause the Moon apparent size to vary in a day. However, in reality, the Moon appears in the same size all day, and it proves that the flat-Earth model does not represent reality and that the Moon is much farther.

## Tycho Crater

The Tycho Crater is a crater on the Moon having the diameter of 85 km (53 miles). It is too small to recognize using the naked eye. However, it lies on a bright colored highland that can be mistaken as the crater itself. The crater also has an extensive ray system, which was from the ejected materials when the crater was formed.

Flat-Earthers claimed the visibility of the Tycho Crater proves the Moon is not that far. They are wrong. We cannot see the Tycho Crater using the naked eye. What is visible is the highland it lies on or its extensive ray system.