Help for a Discussion with flatearthers and moonlanding deniers

[Dr.Acula]

After a long time, I am back. Actually I’m talking to some conspiracy theorists on Instagram. I noticed that many moon landing deniers are also convinced of the flat earth. Now, as "proof", I was presented with a publication from the Ames Research Center, that NASA also considers the earth to be flat. The publication is the NASA Reference Publication 1207 “Derivation and Definition of a Linear Aircraft Model” by Eugene L. Duke, Robert F. Antoniewicz and Keith D. Krambeer.

The summary reads: “This report documents the derivation and definition of a linear aircraft model for a rigid aircraft of constant
mass flying over a fiat, nonrotating earth. The derivation makes no assumptions of reference trajectory or vehicle symmetry. The linear system equations are derived and evaluated along a general trajectory and include both aircraft dynamics and observation variables.”

Since I am not an aviation expert, I would like to know how this introduction should be understood. Flatearthers take this document as proof that NASA also describes a flat earth. I know that there is a wealth of knowledge available here, so I thank you in advance for your help.

[bknight]

I have not read the document but flying flat terrain (Earth) very likely describes flying over non mountainous terrain.  But that is just cherry picking on the part of CTs.

[Dr.Acula]

That was my first thought either, but I'm struggling with the term nonrotating

[LunarOrbit 🇨🇦]

This is how Microsoft Copilot summarizes that report:


This report, titled "Derivation and Definition of a Linear Aircraft Model," was published by NASA's Ames Research Center and authored by Eugene L. Duke, Robert F. Antoniewicz, and Keith D. Krambeer. The purpose of the report is to establish a linear aircraft model for a rigid aircraft of constant mass, flying over an idealized flat, non-rotating Earth.

Key Points:

- Linear Aircraft Model: The report aims to derive and define equations for a linear aircraft model.

- Rigid Aircraft: The aircraft is considered rigid, meaning it doesn't deform or change shape.

- Constant Mass: The mass of the aircraft remains constant throughout the analysis.

- Flat, Non-Rotating Earth: The model assumes the Earth is flat and non-rotating for simplicity in mathematical derivation. This is a common approach in many engineering and physics problems to simplify calculations.

- No Assumptions of Reference Trajectory or Vehicle Symmetry: The derivation does not assume any specific flight path or symmetry in the aircraft's design.

- General Trajectory: The equations are evaluated along a general trajectory, covering various possible flight paths.

- Aircraft Dynamics and Observation Variables: Both the dynamics of the aircraft and the variables that can be observed during flight are included in the system equations.

The mention of a "flat, non-rotating Earth" is a mathematical simplification to make the derivation of the equations more straightforward and manageable. It does not imply that NASA believes the Earth is flat. In scientific and engineering contexts, simplifying assumptions are often made to focus on the primary aspects of a problem without getting bogged down by unnecessary complexities.

[Dr.Acula]

Thanks for clarifying, although I suspect, this will  be handwaved away as usual.

[LunarOrbit 🇨🇦]

Thanks for clarifying, although I suspect, this will  be handwaved away as usual.

Absolutely. If the 24 hour Antarctic sun experiment didn't convince them, nothing will.

[Dr.Acula]

Yeah, Jeran is now called a paid shill. 

[Jason Thompson]

Since I am not an aviation expert, I would like to know how this introduction should be understood.

The simple answer (which drives conspiracy theorists nuts) is that if you're not an aviation expert it shouldn't. Papers like this, in any technical field, are written for people working in the field, not laypeople, and certainly not random conspiracy theorists without a hint of background in the relevant disciplines.

However (and not being an aviation expert myself but having some technical background), in essence this appears to be an example of calculation of a simplified set of general parameters that provide the basis of more detailed analyses and models. They have reduced a complex system to some key elements in order to give a model onto which other variables can be added to more closely meet real world situations. Rather like the ideal gas equation, which models movement of gas molecules in ways that don't actually occur in any real situations but which model the fundamental underlying elements.

So, the major assumptions made and my thoughts on them:

The plane is a rigid body that does not change shape. Broadly true but many aircraft have a degree of flexibility in their structures and all have moveable control surfaces to change how they move through the air, up to and including swing-wing designs that have very different flight characteristics depending on the position of the wing.

The plane has a constant mass. Never true since it burns fuel during flight, so mass is always decreasing to some extent. However in most cases the bulk of the vehicle makes up the majority of the mass and the difference caused by loss of fuel mass is quite small.

Flat Earth: Firstly, this certainly refers to an absence of topgraphical variation, i.e. not considering mountains, valleys, hills, cliffs, land or sea etc. Secondly, assuming a spherical Earth with constant gravitational pull at a given altitude, there is no difference between flying around a sphere and flying across a plane, as the aircraft retains the same relationship to the ground in both cases (it doesn't actively work to move in a circle around a spherical Earth), therefore flight around a spherical Earth can be modelled as flight across a flat one.

Non-rotating Earth: This is just removal of the variable of the motion of the ground under the plane.

So, what this paper is referring to is a basic model of flight, which provides the fundamental underlying conditions onto which other variables (such as the rotation of the Earth, or the loss of mass due to consumption of fuel, or the effect of changing topography, or the effect of changing the shape of the aircraft during flight) can be introduced to more closely model real world situations. It is certainly not saying the Earth is actually flat and non-rotating. The flat-earthers who use this as evidence are ignoring that assumptions are being made about the aircraft that are not true in real-world flight situations, because then they'd have to explain why those assumptions clearly don't mean all aircraft have constant mass and rigid structures, while the assumptions about the Earth do supposedly mean that is what Earth is really like.

[Zakalwe]

I noticed that many moon landing deniers are also convinced of the flat earth.

It's the well-known phenomena called crank magnetism.
Once you go down a rabbit-hole you then have to accumulate other nutty beliefs to maintain the original belief.

https://rationalwiki.org/wiki/Crank_magnetism

[bknight]

That was my first thought either, but I'm struggling with the term nonrotating

Can we see a rotating Earth from spacecraft/airplanes?  The answer is no the observation is no acute enough to discern and ground movement, although it is there no matter which direction we are travelling.  Take for example a vertical stick place into the ground, it casts a shadow, but that shadow moves in relationship to the Earth's rotation.  The shadow takes a finite time perhaps fifteen minutes to move enough to draw a connecting line between the points to discern the north direction.  The shadow will move faster in the early morning or late afternoon and might be faster than fifteen minutes.