A ship disappearing from the bottom first is an effect of Earth’s curvature. It is not a direct observation of the curve itself. We can only directly see the curve from a high altitude, not from near the surface.
Flat-Earthers present this reality as if it is a dilemma: 1. Earth is too big for us to see the curvature, but 2. We can see ships go over the curvature. It is a false dilemma. Ships disappearing from the bottom first is an effect of Earth’s curvature. Such an observation is different from directly witnessing the curve itself.
Continue reading “Curvature Dilemma”
Flat-Earthers love to observe the visibility of a distant object. But the observation can never prove Earth is flat.
The observation of a distant object can only go as far as to disprove Earth is a sphere with a radius of 3959 miles. A flat Earth is merely one of the so many possibilities, but it is still possible the Earth is a sphere, only much larger.
Continue reading “Invalid Hypothesis for the Observation of a Distant Object”
The surface of the water in a container with a width of one meter (3 ft) will have a curvature of 0.000002 cm from Earth’s gravity. As a comparison, a single SARS-CoV-2 coronavirus is at least 0.000005 cm in diameter, or at least 2½ times larger.
If a SARS-CoV-2 coronavirus is not visible to the naked eye, then there is no reason to expect that we will be able to see the much smaller curvature of the surface of water.
Continue reading “Earth’s Curvature and the Size of a Coronavirus SARS-CoV-2 Causing the COVID-19 Outbreak”
Dizzib’s Earth Curve Calculator is one of the most popular Earth’s curvature calculator on the Internet. However, it does not account for atmospheric refraction and, therefore, unsuitable for determining the visibility of a distant object.
Many flat-Earthers used Dizzib’s calculator to analyze the observation of the visibility of a distant object and led them to an erroneous conclusion. If we can spot the calculator being used in their images, we can easily rule out their conclusion.
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The horizon appears flat because the curvature is too small when observed from near the Earth’s surface. However, in some cases, we can exaggerate the curve by taking photographs of the horizon and then magnifying the results vertically.
Magnifying in such a way will also magnify the distortions introduced by the camera lens. We will need to control these distortions using proper photography techniques, or by placing a known straight object as a control object in the frame, close to the horizon. If successful, then the remaining curvature in the photograph can only come from the curvature of the Earth.
Continue reading “Magnifying Images Vertically to Reveal Earth’s Curvature”
There is a legendary diagram of spherical Earth from flat-Earthers that was made using AutoCAD involving the Pythagorean theorem, flaunting the fact that it is was created “using AutoCAD 2016 with 15-digit precision”™. The diagram is not wrong, but it does not account for the height of the observer and atmospheric refraction. And therefore, it is unsuitable for determining the obstruction of a distant object due to Earth’s curvature.
The numbers in the diagram will give us a much higher number than it should be. If a distant object is visible, but according to the diagram it should not, then flat-Earthers will incorrectly conclude that the Earth is flat.
Continue reading “The Legendary AutoCAD Diagram Involving the Pythagorean Theorem from Flat-Earthers”
Due to Earth’s curvature, a distant but still visible object is slightly leaning away from an observer. However, the angle is minuscule and undetectable to any observer.
After being shown photos showing the obstruction of a distant object due to Earth’s curvature, flat Earthers would often shift the topic by pointing out that the tilt due to Earth’s curvature is not apparent in those photos. In reality, the tilt is too small and not visible to our eyes.
Continue reading “The Angle of a Distant Object Due to Earth’s Curvature”
Offshore wind farms consist of a series of large turbines having a similar shape and size. In some cases, they are spread over a very large area of water. They are suitable landmarks where we can easily observe the effect of the curvature of the Earth.
If the turbines are far enough, the bottom parts will not be visible and the blades can look as if they are submerged. The phenomenon is only possible if Earth is a sphere.
Continue reading “Offshore Wind Farms and the Curvature of the Earth”
Lighthouses are equipped with powerful lights. In a dark night, even if Earth’s curvature obscures the entire structure of the lighthouse, the phenomenon of the loom of the light allows their lights to be visible beyond the horizon; not unlike how the beam of a green laser is visible to our eyes.
Flat-Earthers like to point out the cases where the light from a lighthouse is visible even if the lighthouse should be completely obscured by Earth’s curvature. They would claim it as “proof” that the Earth is flat. They are wrong. The loom of the light lets us see the light even when the lighthouse itself is below the horizon.
Continue reading “Lighthouses and the Loom of the Light”
If a distant boat is not visible, then it is because of at least one of these reasons:
- Our eyes have limited angular resolution and are unable to resolve the ship at that distance.
- The atmospheric condition is limiting our visibility.
- The curvature of the Earth obscures the ship.
Flat-Earthers like to demonstrate that a previously invisible ship at a distance can be made visible by zooming in. They would use it to disprove Earth’s curvature. They are wrong. There are reasons other than Earth’s curvature that can obscure a distant boat.
Continue reading “Zooming In On Distant Boats Does Not Disprove Earth’s Curvature”
Railways are built to follow Earth’s terrain, minimizing the grade/slope as much as possible. Consequently, they all follow Earth’s curvature. And many of them were built by explicitly accounting for the curve of the Earth.
Flat-Earthers claim that railroads are straight, and never built by accounting for Earth’s curvature. They are wrong. The leveling works were done in such a way to minimize the effect of Earth’s curvature. There are also multiple books describing railroad constructions where the curvature of the Earth is specifically accounted for.
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Observing Earth’s curvature is more difficult when we are too close to Earth’s surface. The highest place within reach of the general public is a commercial passenger flight. Even then, it is still difficult to casually discern the curvature of the Earth from an airplane. With some effort, it is possible to observe the curve of the Earth from a location closer to the surface, as long as we are willing to do some planning and careful observation.
Continue reading “Observation of Earth’s Curvature from Near the Surface”
The “eight inches per mile squared” is a rule of thumb to determine the drop height due to the curvature of the Earth. It does not account for the observer’s height and atmospheric refraction. And therefore, the rule is unsuitable to determine the amount of obstruction of a distant object due to Earth’s curvature.
Many Flat-Earthers often use the “8 inches” rule to reach the conclusion similar to “X is visible, but at the distance of Y miles, X should be Z feet below the horizon, so the Earth is flat.” They are wrong. The “8 inches” rule is the wrong tool for the purpose as it does not account for the height of the observer and atmospheric refraction.
Continue reading “Eight Inches Per Mile Squared”
The Humber Bridge, near Kingston upon Hull, East Riding of Yorkshire, England, is a 2.22-kilometer (1.38 mi) single-span road suspension bridge, which opened to traffic on 24 June 1981. When it opened, the bridge was the longest of its type in the world.
The towers, although both vertical, are 36 mm (1.4 inches) farther apart at the top than the bottom due to the curvature of the earth.
To an observer, the law of perspective will cause objects moving away in a straight line to:
- appear to approach the vanishing point but never quite reach it,
- never appear to go across the vanishing point,
- appear to shrink in size,
- 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.
Continue reading “Flat-Earth “Perspective” is not Real-World Perspective”
The amount of horizon curvature that appears in a photograph of the horizon depends on several factors:
- The altitude of the observer.
- The field of view of the camera.
- Lens distortions of the camera.
Some flat-Earthers assume that we should see the same amount of Earth’s curvature everywhere. And when they see the different amount of curvature in the different picture of Earth’s curvature, they wrongly took it as “proof” of some sort of misconduct.
Continue reading “The Amount of Curvature that Appears in Photographs of the Horizon”
“Behind the Curve” is a documentary showing behind the scenes on what is happening in the flat-Earth community in the United States just before a flat-Earth conference. In a section, the film shows us how a flat-Earther tried to disprove curvature using a series of visual experiments. The result clearly indicates the surface curves, but he was unwilling to accept the fact.
Continue reading ““Behind the Curve”: the Earth’s Curvature Experiment”
Earth’s curvature is hard to observe from the surface. Even from the altitude of a commercial passenger flight, about 30000-40000 ft, Earth’s curvature is still too small to notice. However, under careful observation, it is not impossible to confirm the curve from the cruising altitude of a jet airliner.
Continue reading “Observing Earth’s Curvature on a Flight”
In most situations, atmospheric refraction bends light downwards and causes objects to appear higher than they actually are. The strength of atmospheric refraction is not constant. It depends on weather condition and varies on the different seasons, different days, and even different times of the day.
Because of the variability of atmospheric refraction, a distant object that is usually obstructed by Earth’s curvature can sometimes be visible. Some flat-Earthers would cherry-pick moments when the object is visible. They would show such specific moments to everyone and use them to “disprove” Earth’s curvature; happily ignoring the cases where Earth’s curvature partly or entirely obstructs the object.
Continue reading “Variability of Atmospheric Refraction”
Auguste Piccard was a Swiss-Belgian physicist, inventor, and explorer, known for his record-breaking balloon flights to the stratosphere, as well as the invention for bathyscaphe to allow for deep ocean exploration.
Unfortunately for him, flat-Earthers are claiming him as their own these days. It started from a Popular Science article from 1931, saying:
Through portholes, the observers saw the earth through copper-colored then bluish, haze. It seemed a flat disk with upturned edge.
But, no. In reality, Auguste Piccard was not even close to being a flat-Earther.
Continue reading “Auguste Piccard, Another Scientist Falsely Claimed by Flat-Earthers”