It is impossible to positively prove the authenticity of a photo beyond any doubt unless we take the photos ourselves. Instead, we gather as much information as possible related to the photo, evaluate the information, then use inductive reasoning to determine if the photo is real. And the conclusion will always be a probability, not a certainty.
Flat-Earthers like to demand us to prove that a particular photo is real, and if we cannot, they will conclude the photo is fake. In reality, while we might be able to prove a photo is not real, at the very best, we can only say there is no reason to believe the photo is not real from all the available information. This applies to practically all photos and also plenty of other things in everyday life.
Continue reading “Determining the Authenticity of a Photo”
The sunlit part of the moon is far brighter than the stars in the background. But cameras have dynamic range limitations. They cannot capture extremely bright and extremely dim objects at the same time. We can increase the exposure to reveal the stars, but then the moon will appear washed out, with no visible details.
Flat-Earthers use the lack of stars in photos taken from space to dismiss them as fake. In reality, the reason for the lack of stars is the same reason stars are also missing in photos of the Moon taken with the correct exposure.
Continue reading “Camera Exposure Settings to Capture the Moon and Stars”
Visual albedo is the measure of the reflection of sunlight out of the total solar radiation received by an astronomical body, taking into account only the visible light. The visual albedo of the Earth is 0.37, and the Moon’s is 0.12.
The Moon appears dark if the Earth also appears in the same photograph. Flat Earthers use the fact to dismiss such photos as fake. In reality, the Moon’s brightness in a photo is just a matter of choosing the correct camera exposure. But if Earth is also present, increasing the exposure will make the Earth appear too bright.
Continue reading “Visual Albedo of the Moon and the Earth”
Glare can appear around light sources, causing them to appear larger in a photo. The higher the exposure value of the camera, the larger the glare will appear on the resulting photo.
Much flat-Earth misinformation arises from misunderstandings about photography, such as about glare and how to eliminate glare by changing the exposure or by using a solar filter. Using the exposure setting for everyday scenes to capture a photograph of the sun will give us a glare around the Sun. To take a photo of the actual size of the Sun, we need to reduce the exposure, either by changing the in-camera exposure settings or by using a solar filter.
Continue reading “Glare”
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.
Continue reading “Perspective of Earth Due to Different Observer Distance”
The images showing the progress of a lunar eclipse were taken in increasing exposures to compensate for the decrease in brightness. The exposure increase from full moon to totality can reach 12EV or 4000× increase in light-gathering power.
Images showing the progress of a lunar eclipse appear in a constant brightness, and flat-Earthers —presumably never seen it in person— use it to “prove” a lunar eclipse is not caused by Earth’s shadow. In reality, the images were kept in a constant brightness by increasing the exposure of the camera.
Continue reading “Constant Image Brightness in Images of a Total Lunar Eclipse”
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.
Continue reading “ISS Size Compared to an Airplane in a Photograph”
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.
Continue reading “Camera “Maximum Range””
Earthshine is a glow in the dark areas of the Moon because sunlight reflects off Earth’s surface to the Moon’s night side. Earthshine can be easily observed with long-exposure photography.
Some flat-Earthers claim that the Moon is transparent or that it is not a sphere. By observing the earthshine using a camera with the correct exposure, we can easily disprove such claims.
Continue reading “Earthshine and Moon Phase”
At the longest zoom, the Nikon P1000 has a field of view of 0.2°, which is equivalent to 1342 km at the Moon’s distance.
Flat-Earthers zoomed their Nikon P1000 at the Moon and claimed that they could not find flags and landers from the Apollo missions. In reality, the smallest objects on the lunar surface they can observe using their cameras are large city-sized objects.
Continue reading “Zooming at the Moon”
Sunlight is very intense. It can cause glare to appear around the sun, and as a result, the sun can appear larger than its actual size. To observe the sun’s actual size, we need to eliminate the glare by reducing the camera’s exposure or using a solar filter.
During sunset, sunlight gradually becomes less intense, and sun glare gradually becomes smaller. If the glare is not eliminated, the sun can appear as if it is shrinking, and flat-Earthers incorrectly use it as “evidence” that the sun is moving away from us.
Continue reading “Sun Glare”
From an observer on a shore, the distance to the horizon is 5 km (3 miles), or more if the observer is higher. Therefore, Earth’s curvature obscures objects starting from that distance. If the objects are not large enough, we need an optical aid, like zooming in using a camera, to see them in the first place.
Flat-Earthers often show us wide-angle photos to demonstrate that objects are not obscured by Earth’s curvature. In reality, in such photos, objects far enough to be obscured by Earth’s curvature cannot be resolved. It is hard to see objects obscured by Earth’s curvature if the objects themselves are not visible in the picture.
Continue reading “Objects Obscured by Earth’s Curvature and Zoom Factor”
Flat-Earthers performed the coin on a table “experiment” to “explain” how a sunset can occur on a flat Earth. Instead, it tells us more about their confirmation bias.
This is probably one of the most ridiculous flat-Earth arguments. It is so obviously wrong that many of us are having trouble explaining it and cannot accept that a member of the human race can fall for it.
Continue reading “Coin on a Table “Experiment””
Earth seen from the Moon will appear 3.7× larger than the Moon seen from Earth. However, if a photograph of Earth is compared to that of the Moon, the sizes of both objects also depend on the field of view of the cameras that were used to capture them.
Flat-Earthers discovered the size of the Earth in a photograph is not 3.7× the Moon in another picture. They used the fact as “evidence” of wrongdoing. In reality, the two photos were not taken with the same field of view, and cannot be compared directly.
Continue reading “Earth Seen From the Moon vs the Moon Seen From Earth”
Angular resolution is the minimum separation between distinguishable features in an image. Objects smaller than the angular resolution are indiscernible in the picture. The theoretical maximum angular resolution is determined by the diameter of the aperture of the optical instrument.
Flat-Earthers like to demand images of the lunar landers taken with a telescope as proof that the Apollo Moon landings did occur. In reality, no optical telescope on Earth is large enough to resolve the landers.
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The Earth is an oblate spheroid. Its diameter is longer across the equator than between the poles. The difference is tiny, only about 0.3%. It is not possible to notice the oblateness from photographs taken from space without careful measurement.
Flat-Earthers claim that in photos taken from space, Earth appears as a perfect sphere, unlike what science tells us, and they use it to discredit science. In reality, it is possible to notice the oblate shape with careful measurement of the images.
Continue reading “Oblate Spheroid Shape of the Earth”
The entrance pupil is the opening in front of a camera that allows light to enter. If it is partially obscured, light can still come through the unobscured part, and the camera can still see the object.
In one of those “experiments,” flat-Earthers placed an obstacle in front of a camera, very close to the lens, so that an object is partially visible. At the widest angle setting, the person appears partially visible. But it turned out that zooming in will fully reveal the person. Flat-Earthers claim it is how objects can vanish behind the horizon if Earth is flat and how they can reappear by zooming in. In reality, zooming enlarges the camera’s entrance pupil, letting the camera to see over the obstacle.
Continue reading “Camera Entrance Pupil Size and the Zoom Factor”
Geostationary satellites orbit the Earth with the same rate as Earth’s rotation, 35786 km (22236 miles) above the equator. They are too far and too dim for the naked eye. However, we can observe them using a mounted telescope and a camera.
We can observe many of them by:
- using an equatorial mount,
- aiming the telescope at a star that lies in the orbit’s path, and
- use a camera with a long exposure setting.
Continue reading “Observing Geostationary Satellites”
A telephoto lens is a type of lens in which the physical length is shorter than the focal length. A telephoto lens has a narrow field of view, and as a result, the curvature of the Earth is less pronounced if taken using a telephoto lens compared to another lens with a wider field of view.
Flat-Earthers like to bring up pictures taken from the ISS that show a practically flat horizon, and use them as evidence of inconsistency. In reality, the images were taken using a telephoto lens with a narrow field of view.
Continue reading “Telephoto Lenses and the Appearance of Earth’s Curvature”
To an optical device, like a camera, there is little difference between an airplane at 20000 ft and the Moon at 384400 km (238855 mi). The aperture of the lens is far too small compared to the distance of either object. Focusing on either object will make the other object in focus, too.
Flat-Earthers claim that because both objects appear in focus in a photograph, then the Moon must be close to the airplane. In reality, both can be considered at infinity. And it will be easy to make both objects to be in focus simultaneously.
Continue reading “Infinity Focus”