When we are unable to see a distant object, then it is due to one of these reasons:
- Our eyes lack the sufficient angular resolution to recognize the object.
- Atmospheric condition limits visibility.
- The object is far enough and obscured by Earth’s curvature.
Some flat-Earthers like to show that a previously unseen distant object can be brought into view using infrared vision. They would take that as ‘evidence’ of the non-existence of Earth’s curvature. They are wrong. Infrared vision can reveal hidden objects caused by visibility limitations, but not ones obscured by Earth’s curvature.
Continue reading “Infrared Vision”
Flat-Earthers reject the existence of satellites. They are wrong. To prove the existence satellites, we can attempt to take pictures of the ISS when an ISS transit happens, or the ISS passes in front of the Sun or the Moon.
Continue reading “Observing the ISS from ISS Transits”
There are videos showing the sun to appear to set, but after the camera is zoomed in, the sun is still above the horizon. The reason is that the camera’s autoexposure system is constantly adjusting the exposure, and in such scenes, there’s a difference in overall brightness before and after zooming in.
Flat-Earthers are taking such videos as ‘evidence’ of a receding sun. They are wrong. This is merely a matter of photography. In reality, the sun is not receding, and it has the same angular size throughout the day.
Continue reading “Sunset, Camera Zooming, and Autoexposure”
The amount of curvature that appears in a photograph of a sphere depends on 1. The radius of the sphere, 2. Camera distance from the sphere, 3. Field of view of the camera, and 4. The distortion characteristic of the camera being used.
The ‘curvature fitting game’ has been flat-Earthers’ favorite pastime. They would try to fit a photograph of Earth’s curvature with another. If they find the result is not proportionally correct, they will make fun of it. They are wrong. Two different photos of a sphere can be taken differently and would show a different curve, even if the object being photographed is the same object.
Continue reading “The Curvature Fitting Game”
Action cameras are being used in high-altitude balloons, rocket launches, and the ISS because they have some advantages compared to other cameras. And most action cameras are equipped with a fisheye lens.
Flat-Earthers allege that there is an evil intention behind every use of fisheye lenses, especially in space and high-altitude usages. They are wrong. The use of fisheye lenses is not unreasonable. And if a rectilinear result is desired, it is trivial to convert any fisheye footage to a rectilinear one.
Continue reading “The Reasons Why Fisheye Lenses Are Used”
Polaris is a bright star that is close to the north celestial pole. Currently, Polaris is only 0.74° apart from the north celestial pole and the only star visible to the naked eye that is close to the celestial pole. This is why Polaris is popular as a navigational aid in the northern hemisphere.
Some flat-Earthers think that Polaris is stationary and that it is a ‘special star’ because other stars are in motion around it. They would take that as ‘evidence’ that the Earth is motionless. They are wrong. Polaris is merely a regular star, just like the others.
Continue reading “Polaris is not Stationary in the Sky”
A fisheye lens distorts images. It results in images having barrel distortions. In a fisheye lens, a straight line can appear curved. But some flat-Earthers don’t realize that the opposite is also true, a fisheye lens can easily make a curved line look straight.
Continue reading “Fisheye Lenses Can Make Curved Lines Appear Flat”
In many pictures taken from space, stars are not visible, even with a dark sky. The reason is that stars are very dim compared to the primary object in the pictures. If the camera is set to take a correctly exposed image of an object that is much brighter than the stars, then the stars would not be visible in the picture. The same thing would happen everywhere, in space, or on the surface of the Earth.
Flat-Earthers often take the lack of stars as fakery. They are wrong. This is simply a limitation of any camera.
Continue reading “The Lack of Stars in the Pictures of Space”
The Sun has the angular size of approximately 0.53° seen from Earth, and it is practically constant throughout a single day. But sunlight is very intense and result in a glare that surrounds the Sun. Because of the intensity, we are unable to distinguish the Sun from its glare.
During a sunset, the intensity of sunlight is lower due to the fact that sunlight has to traverse Earth’s atmosphere at an angle. Because of the reduced intensity, the amount of glare will also be reduced, and the Sun can look as if it is shrinking.
Flat-Earthers often use this phenomenon as ‘evidence’ of a receding Sun during a sunset. They are wrong.
Continue reading “Sun Glare Makes the Sun Appear Larger”
Zooming in using a camera merely magnifies the center portion of the image. Changing zoom does not change an object’s position with respect to another object or the camera. It will not reveal more of a distant object.
Flat-Earthers often claim that zooming in will reveal distant objects that are ‘allegedly’ behind the curvature. They are wrong. If the object is really behind the curvature, then no amount of zooming can bring the object back into view.
Continue reading “Zooming in Will Not Reveal More of a Distant Object”
Soundly’s pictures and videos of Lake Pontchartrain power lines and causeway stirred up the flat-Earthers’ nests. They clearly show the curvature of the Earth, where it is usually hard to discern. For the rest of us, those pictures are just the consequence of the fact that the Earth is a globe.
Flat-Earthers can’t take this, and they invented various excuses to attack the credibility of these pictures and videos. Some of them look for specific vantage point where it is impossible or very hard to discern the curvature. They would conclude if the curve is not seen from these vantage points, then it should not be visible from Soundly’s viewpoints.
Continue reading “Perspective Compression: Determining If a Curvature Exists”
High-altitude balloon footage is often abused by flat-Earthers to show us that the Earth is flat when seen from a high altitude.
We analyzed more than two dozens of footage taken from high-altitude balloons on YouTube, and we can easily conclude the curvature is there and usually easy to spot, including in the cases where flat-Earthers use the video as ‘proof’ of a flat Earth.
Continue reading “Curvature of the Horizon in High-Altitude Balloon Footage”
Sometimes, we can see clouds appearing as if they are behind the Sun or the Moon. Obviously, this is merely an illusion. But some flat-Earthers regard this as ‘evidence’ that the Sun and the Moon are close and apparently closer than some clouds. They are wrong.
Continue reading “The Illusion of Clouds Appearing ‘Behind’ the Sun or the Moon”
During a total solar eclipse, the Moon is right between the Earth and the Sun. Thus, the near side of the Moon does not receive any sunlight. But while it is dark, it still gets some light reflected by the surface of the Earth. This phenomenon is called Earthshine.
Some flat-Earthers argue that a solar eclipse is not caused by the blocking of the Sun by the Moon, but by another, mysterious celestial body. The reason is that eclipses are incompatible with their beliefs about the motion of the Sun and the Moon.
Earthshine proves that they are wrong.
Continue reading “Earthshine Proves the Moon Obscures the Sun During a Total Solar Eclipse”
In photography, the starburst effect gives the illusion of light rays from strong light sources in an image. The effect happens when the lens’ aperture is not a perfect circle, and it gets more pronounced under a narrower aperture.
Flat-Earthers often find themselves looking for any peculiarity —no matter how small or unbelievable— to discredit any picture they deem unacceptable to their misguided causes. One of this peculiarity is the starburst effect.
Continue reading “The Starburst Effect is not Evidence of CGI”
The Earth is not perfectly spherical. Its diameter is longer across the equator than between the poles; it is oblate spheroid. This fact is often questioned by flat-Earthers. According to them, every picture of the Earth from space shows the Earth as a perfect sphere, and never as an oblate spheroid. Then they would present it as ‘evidence’ that scientists have been lying to us.
But it is actually possible to determine that the Earth is in fact oblate spheroid from pictures of the Earth taken from space.
Continue reading “The Oblate Spheroid Shape and Pictures of the Earth From Space”
Ever seen a video where a flat-Earther tries to demonstrate that a distant object that appears to be behind an obstacle can be brought back into view simply by zooming in? He would then conclude the same thing would happen when zooming in to a distant ship, and the reason a distant ship is not visible is not the curvature of the Earth.
Well, no. The real reason why the object in that experiment can be seen after zooming in is that the obstacle is close, and there’s difference in the camera’s entrance pupil size when the zoom changes. For a camera that has very long zoom range —like the Nikon P900—, the difference can be very dramatic.
Continue reading “Difference in Entrance Pupil Diameter: The Real Reason Why An Obscured Object Appears When Zoomed In”
Lake Pontchartrain is a lake in Louisiana, United States. There are power transmission lines about 24.27 km (15 mi) across this lake. They are practically straight, and each tower is uniform and has the same height, making these towers ideal for observing the curvature of the Earth.
They were first popularized by Soundly who presented evidence of Earth’s curvature using a series of photos and videos of the power lines in June 2017. As of now, the towers and other objects on the lake are probably the most popular Earth curvature tourism spot in the world.
Continue reading “Lake Pontchartrain Power Transmission Lines: Evidence of Earth’s Curvature”
“Looking at the pictures of the progression of a lunar eclipse, the Moon turns red, but there’s no apparent change of brightness of the Moon as it progresses from full moon to total eclipse. Therefore, a total lunar eclipse cannot be the result of the Earth casting its shadow on the surface of the Moon.”
Some flat-Earthers —presumably never seen a total lunar eclipse in person before— actually claim that.
Continue reading “Brightness of a Total Lunar Eclipse”
In the northern hemisphere, if we look at the sky to the north, we can observe stars rotate counter-clockwise around a point. This axis of rotation is not visible from observers in the southern hemisphere.
On the other hand, in the southern hemisphere, if we look at the sky to the south, we can observe stars rotate in the opposite direction. Conversely, this axis of rotation is not visible from observers in the northern hemisphere.
This motion of the stars cannot possibly happen in a flat-Earth. The motion of the stars is a proof that the Earth is round and rotates around its axis.
Continue reading “Star Trail: Evidence the Earth is a Sphere and Rotating Around Its Axis”