## Reasons for Preferring Flight Routes With a Stop to the Non-Stop Routes

Many flight routes cannot possibly exist if Earth is flat. Flat-Earthers showed the availability of the same routes with a stop to “prove” the non-stop routes do not actually exist. In reality, there are reasons airlines provide these routes with a stop, and some passengers do prefer to fly these routes.

## Perth–Johannesburg Flight Route

By comparing the duration of the non-stop Perth–Johannesburg flight route with the same route with a stop, we can conclude the route is only possible if Earth is a sphere.

There are other Perth–Johannesburg flights but with a stop, like in Dubai. Flat-Earthers use it to “prove” a flat Earth. In reality, it does not mean the non-stop route does not exist. And it is easy to verify the existence of the non-stop route. These are consistent only with a spherical Earth and can never be explained if the Earth is flat.

## Non-Stop, Long-Haul Flight Routes in the Southern Hemisphere

There are many non-stop, long-haul flight routes between different continents in the southern hemisphere, without crossing the northern hemisphere. These routes are only possible if Earth is a sphere, and impossible if Earth is flat.

Flat-Earthers claim that all long-haul flights south of the Equator always do a stop north of the Equator. In reality, there are plenty of non-stop routes between these locations, showing that Earth is a sphere.

## Where’s the Curvature?

A human eye can only visually perceive the curvature of the Earth if we are at a considerable altitude from the surface, which is still beyond the reach of most humans today. A commercial jet airliner is the highest position realistically attainable by most humans today. We can only perceive very slight curvature at such altitude and, even then, only in an ideal condition.

The basis of flat-Earthers’ belief is that the horizon appears flat. They would say if we cannot see the curvature, then there’s no curvature, and therefore, the Earth is flat. In reality, only a few people can travel high enough to see the curve.  The highest we can realistically go is by getting on a commercial jet airliner, which can only go about 11-15 km up, only a fraction of Earth’s radius.

## Sydney-Santiago Flight Route

The Sydney-Santiago flight route is one of the southernmost passenger flights. Such a route is impossible if Earth were flat and confirms that Earth is a sphere. It is easy to verify the existence of this route from flight websites.

On a flat Earth, this route should go across the United States. But the duration of the Sydney-Santiago route with a stop in the US is much longer than the non-stop route because Earth is a sphere, and this route does not go anywhere near the United States.

## Sydney-Johannesburg Flight Route

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.

## Pilots Are Taught to Work With the Fact Earth is a Sphere

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.

## Airplanes Will Never Fly Into Space

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

## Spirit Level on an Airplane

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.

## New York JFK – Moscow SVO Flight Time-Lapse Videos

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.

## Human Perception of Speed and Acceleration

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.

## Bottled Water: A Simple Device for Observing the Dip of the Horizon

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.

## The Taiwan–Los Angeles Flight (not from Bali) that was Diverted to Anchorage

There was a flight from Taiwan to Los Angeles that was diverted to Anchorage because one of the passengers gave birth to a baby. Flat-Earthers use the case as one of the first “evidence” from flight routes proving Earth is flat.

They are wrong. The case only tells us about the ignorance of these flat-Earthers about the distortion in a map projection. Their argument started with an elementary mistake of taking a straight line on a Mercator map between Taiwan and Los Angeles, and assume it as the “intended flight path.”

## The Failure of Flat-Earth Model to Explain Emergency Landings That Occur More to the South

The perpetrators of flat-Earth often take emergency landings as ‘proof’ of a flat Earth. They would point out that the diversion airports used for such emergency landings are somehow consistent with the flat-Earth map.

It is not a coincidence that all the cases of emergency landing they pointed out occurred far in the north. At the locations closer to the north pole, the distortion of the azimuthal-equidistant map (claimed by flat-Earthers as the ‘flat-Earth map’) diminishes. It would seemingly appear as if the ‘flat-Earth map’ can explain the choice of the diversion airports. In many other locations, though, the flat-Earth map would fail to explain it.

## Emergency Landings and Flight Route

We cannot take a straight line between two locations on a map and consider that line the shortest distance between the two locations. With a very short distance —like within a city— it wouldn’t usually matter. But for long-haul flights across continents, then it would matter a lot.

Flat-Earthers are known to use this mistake —whether deliberately or not— as a ‘proof’ that the Earth is flat. A common case they would bring is emergency landings.