Debunking Flat Earth Misconceptions
The existence of the non-stop Sydney-Johannesburg flight route is only possible if Earth is a sphere. We can find that out by comparing its duration to the same route but with a stop.
There are other Sydney-Johannesburg flight routes, but with a stop, like in Dubai. Flat-Earthers use the existence of these routes to “prove” a flat Earth. In reality, it does not mean the non-stop route does not exist & it is not difficult to verify that the non-stop route exists.
Polar circumnavigation is complete navigation around Earth through both the North Pole and the South Pole. Several parties have successfully done it, and it is only possible if Earth is a sphere.
Flat-Earthers incorrectly claim that Earth circumnavigation has never been done through both the poles, and they use it to “prove” a flat Earth. In reality, many have successfully done such feats.
During the COVID-19 pandemic, many flight routes are being canceled, suspended, or cut down due to lockdowns, travel warnings, travel bans, or insufficient demand. These include flight routes that are impossible if Earth were flat.
Flat-Earthers looked for these routes, and when they could not find them, they use the lack of these routes to “prove” Earth is flat. In reality, they made these lookups during the COVID-19 pandemic, when most of these routes are not available or severely cut down.
An airplane exists on Earth. It has the same motion as the surface of the Earth, including Earth’s rotating motion. The motion and speed of an airplane are measured relative to Earth’s surface.
Flat-Earthers claim that an airplane should not be able to fly eastward or land. In reality, an airplane is moving relative to the surface. It has Earth’s motion as a component of its motion and does not need to chase Earth’s rotation.
Pilots are taught to work with the fact that Earth is a sphere. It is part of the education to become a pilot. Their job depends on the knowledge that Earth is a sphere.
Flat-Earthers wrongly claim that pilots are taught to fly based on a flat Earth. We can easily disprove these claims by reading some of the books these pilots use in their education.
Continue reading “Pilots Are Taught to Work With the Fact Earth is a Sphere”
In making mathematical models, physicists often remove real-world details that have little influence over the final results for simplifications. In flight-dynamics, it is often perfectly adequate to assume Earth is flat & non-rotating, even if the final aircraft will be flying over spherical & rotating Earth.
Flat-Earthers claimed to have exposed ‘a secret document’ from NASA, saying that Earth is flat & non-rotating. In reality, the document is simply a derivation of a flight dynamics problem, assuming flat and non-rotating Earth, which is a common assumption made to simplify flight models. It does not imply the Earth is flat and non-rotating.
Continue reading “Flight Dynamics: the Assumption of Flat & Non-Rotating Earth for Simplification”
Eötvös effect is the change in perceived gravitational acceleration when moving eastward vs. westward. An object will weigh slightly more when moving westward than when it is stationary or moving eastward.
The slight difference in weight due to the Eötvös effect can be measured in an experiment on a flight. The Eötvös effect is direct evidence that the Earth is a rotating sphere.
Continue reading “Eötvös Effect: Direct Evidence Earth is a Rotating Sphere”
The durations of commercial passenger flights are useful proxy data for the distance between cities. They easily debunk flat-Earth. Flat-Earthers invented “explanations” that different airplanes have different airspeeds to dismiss the data. In reality, all current long-haul airliners have a similar cruising speed.
Continue reading “Airspeed of Long-Haul Commercial Passenger Flights”
An airplane relies on the lift from its wings, which depends on the airplane’s speed and the air density. As a result, a cruising airplane will fly at a constant altitude, following the curvature of the Earth.
Flat-Earthers claim if Earth is a sphere, an airplane has to dip its nose down periodically, or it would fly into space. In reality, an aircraft will follow Earth’s curvature and is unable to fly to space even if the pilot deliberately attempts to do that
During cruising, an airplane is practically level. It is flying perpendicular to the direction of gravity. The aircraft is still flying following Earth’s curvature and continuously changes its orientation. However, not only its orientation changing but also the direction of gravity, having the same amount of change. As a result, a spirit level on a flight will not show us the difference in orientation of the airplane due to its motion following the curvature of the Earth.
Drag or air resistance is a force acting opposite to the relative motion of an object with respect to a surrounding fluid. The magnitude of drag is directly proportional to the fluid’s density.
Flat-Earthers claim that because satellites lack an aerodynamic shape, they cannot be faster than airplanes. In reality, the air density at such an altitude is minuscule and will not produce a significant drag. Thus, they do not need an aerodynamic shape.
Auckland, New Zealand and Madrid, Spain are a near antipodal pair. Both are located at the diametrically opposite points to each other on Earth’s surface. Therefore, we can fly from Auckland in any direction and arrive in Madrid after traveling a roughly similar distance, regardless of the direction taken.
Any flight between an antipodal pair has a similar duration even though the different flights have different directions. This fact is only consistent with spherical Earth and cannot possibly be explained if Earth is flat.
Flat-Earthers discovered a map titled “Air Map of the World” from 1943, explaining the flight routes during the time. Because the shape is identical to the fictional “flat Earth map,” they incorrectly claimed that it is a flat-Earth map. In reality, it is an azimuthal equidistant map that has distortions, a flattened shape of the spherical Earth on a flat surface, and does not depict the true shape of the Earth.
The exact nature of the map is even explained in a very detailed manner in the map’s description. Unfortunately, in the flat-Earth community, the map is passed around in a very low resolution, and therefore, the explanations become unreadable.
Shanghai, China and Buenos Aires, Argentina are a near antipodal pair. Both are located at the diametrically opposite points to each other on Earth’s surface. Therefore, we can fly from Buenos Aires in any direction and arrive in Shanghai after traveling a roughly similar distance, regardless of the course taken.
Any flight between an antipodal pair has a similar duration even though the different flights have different directions. This fact is only consistent with spherical Earth and cannot possibly be explained if Earth is flat.
There are several time-lapse videos taken on board of a New York – Moscow flight, looking northward through a window on the left side. In the videos, the sky never looked fully dark, and the sun was visible most of the time on the flight.
Flat-Earthers erroneously assumed that the phenomenon is not possible if Earth is a sphere and that it is “evidence” the Earth is flat. In reality, everything in the videos can be easily explained and is fully consistent with the spherical Earth model.
Continue reading “New York JFK – Moscow SVO Flight Time-Lapse Videos”
When aboard an airplane flying at cruising speed, we will not be able to feel that the plane is, in fact, moving at speed of more than 900 km/h. But if the plane changes its speed, turns or changes its altitude, we can easily feel it.
The same thing happens with the motion of the Earth. Due to Earth’s rotation, the surface of the Earth is moving at 1656 km/h near the equator. We never feel it because the speed is constant, or in other words, the acceleration is zero.
Continue reading “Human Perception of Speed and Acceleration”
The cruising altitude of a jet airliner is about 33000-42000 ft or 10000-12800 m. It is very tiny compared to the radius of the Earth of 6378 km. Therefore, the distance measured at the cruising altitude does not differ much compared to the surface distance.
Some flat-Earthers claim that if Earth is a sphere, the distance traveled by a jet airliner would have been multiple times the surface distance. They are wrong. The air distance at 33000 ft is only 0.16% farther compared to the surface distance.
On many flights, they would give away leveling devices to all passengers for free, so that everyone would be able to observe the dip of the horizon and proves Earth is a sphere. And as a nice side effect, to quench our thirsts, too!
Such devices are called ‘bottled water’. Using these simple ‘instruments’ on a flight, we can demonstrate that Earth is a sphere.
Continue reading “Bottled Water: A Simple Device for Observing the Dip of the Horizon”
A ring laser gyroscope (RLG) is an instrument for measuring the change in orientation and rotational velocity. It is sensitive enough to measure Earth’s rotation easily.
Flat-Earthers claim that there is no instrument able to measure Earth’s rotation. Such claim arose from their ignorance. Ring laser gyroscopes —which are installed in some airplanes and ships— can easily detect and measure Earth’s rotation.
Continue reading “Ring Laser Gyroscopes are Sensitive Enough to Measure Earth’s Rotation”
Earth’s atmosphere is part of the Earth. It practically follows Earth’s rotating motion like the rest of the Earth. Due to various factors, Earth’s atmosphere has relatively small and uneven movement relative to the surface. We call it ‘wind.’ The fastest wind ever recorded is about 408 km/h, relative to Earth’s surface.
Many misconceptions about Earth arise from the wrong idea that only Earth’s solid body is rotating, but the atmosphere is not. If it is true, then we should always feel the wind with the speed of 1674 km/h near the equator, or more than 4× the fastest wind ever recorded. We don’t feel such a wind, and thus we know our atmosphere is moving at practically at the same speed as Earth’s surface.
