NASA and the flat earth airplane...

I was wondering if there is any feasible explanation regarding this article by NASA:

https://websites.godaddy.com/blob/141717ab-a656-42dd-a416-0e1a404d4647/downloads/1bgu1pq66_83327.pdf?8517e905

"This report details the development of the linear model of a rigid aircraft of constant mass, flying over a flat, nonrotating earth (emphasis mine)."

https://physics.stackexchange.com/questions/319909/why-does-nasa-need-an-aircraft-model-flying-over-a-flat-and-nonrotating-earth

"nonrotating means it is not turning. It means the orientation of the earth is constant."

You do not have an individual answer.

Thanks for playing.

I was wondering if there is any feasible explanation regarding this article by NASA:

https://websites.godaddy.com/blob/141717ab-a656-42dd-a416-0e1a404d4647/downloads/1bgu1pq66_83327.pdf?8517e905

"This report details the development of the linear model of a rigid, aircraft of constant mass, flying over a flat, nonrotating earth (emphasis mine)."

Perhaps because when you're developing a model of an aircraft for analysis, the shape or motion of the earth aren't relevant.

Quote from: totallackey on March 01, 2018, 05:57:16 AM

I was wondering if there is any feasible explanation regarding this article by NASA:

https://websites.godaddy.com/blob/141717ab-a656-42dd-a416-0e1a404d4647/downloads/1bgu1pq66_83327.pdf?8517e905

"This report details the development of the linear model of a rigid, aircraft of constant mass, flying over a flat, nonrotating earth (emphasis mine)."

Perhaps because when you're developing a model of an aircraft for analysis, the shape or motion of the earth aren't relevant.

Then why the use of any adjectives at all?

Why not simply state: "This report details the development of the linear model of a rigid aircraft flying over a earth."?

Because the Earth is flat, and you just caught them?

Because the Earth is flat, and you just caught them?

Evidently the Earth is flat according to NASA.

Quote from: markjo on March 01, 2018, 06:25:28 AM

Quote from: totallackey on March 01, 2018, 05:57:16 AM

I was wondering if there is any feasible explanation regarding this article by NASA:

https://websites.godaddy.com/blob/141717ab-a656-42dd-a416-0e1a404d4647/downloads/1bgu1pq66_83327.pdf?8517e905

"This report details the development of the linear model of a rigid, aircraft of constant mass, flying over a flat, nonrotating earth (emphasis mine)."

Perhaps because when you're developing a model of an aircraft for analysis, the shape or motion of the earth aren't relevant.

Then why the use of any adjectives at all?

Why not simply state: "This report details the development of the linear model of a rigid aircraft flying over a earth."?

It's called "defining the scope of the model".  Some models may include the shape and movement of the earth (probably for navigation purposes).  This is simply to note that the model described isn't one of those.

It's called "defining the scope of the model".  Some models may include the shape and movement of the earth (probably for navigation purposes).  This is simply to note that the model described isn't one of those.

Why define a scope of a model for something that, according to science, is absolutely not true?

And do the results of this modeling differ from a linear model of just an ordinary plane model used for "navigation purposes"?

You are sure "flat" does not mean, for example, devoid of mountains or something, in this case?

You are sure "flat" does not mean, for example, devoid of mountains or something, in this case?

Perhaps, but again...

Why be concerned about modeling a plane that would only be operative over purely flat, non-rotating ground, if no such ground exists according to science?

And do the results of this modeling differ from a linear model of just an ordinary plane?

Quote from: rvlvr on March 01, 2018, 08:44:19 AM

You are sure "flat" does not mean, for example, devoid of mountains or something, in this case?

Perhaps, but again...

Why be concerned about modeling a plane that would only be operative over purely flat, non-rotating ground, if no such ground exists according to science?

I leafed thru the paper, not that I understand much of it, but I could not find mentions of flat Earth. And here is the kicker, earth is written in lower case. It is not "Earth".

EDIT: But yes, how the model in paper differs from others I haven't got a clue. I can't read that stuff.

I did a search so this is simply cut and paste:-

All models are wrong. Some are useful.

These days there's a popular trend when simulating things to simulate every possible mechanism we can imagine. Those who think that way would agree with you. Why would you ever make a flat Earth model when everything is eventually going to make its first flight on a real rotating spherical-ish Earth?

This approach works great until you come across real development or computational limits. The cited paper is from 1988. Computers were much weaker back then. For perspective, the Cray Y-MP was sold that year. Its peak performance was 333 megaflops. She cost $15 million dollars. Contrast that to today. A Geforce GTX 1070 is capable of 6,500,000 megaflops (6.5 teraflops) and has a price tag of around $400.

In those days, you didn't waste computational power on frivolities. It turns out that for a vast array of aeronautical problems, the effects of a flat earth vs. round are minimal (much less the effects of rotating vs. not). If you're shooting a shell 15km, and need it to land with pinpoint precision, you need all that extra complexity. However, many aero problems include a guidance unit which would address any error due to Coriolis effects or the spherical ground the same way it would handle any other errors. It'd simply see it wasn't on the right path and make a correction. The other sources of error here, such as winds, play a far larger effect in deviations from a flight plan, so all the rotating and spherical effects can just get lost in the noise.

Even today, we still make flat Earth models. The reason is not computation time, like it was in 1988, but development time. The more things you model, the more things you need to develop, verify, and maintain. If a particular problem does not call for advanced models, why waste budget developing and maintaining them?

A real life example of this shows up in geoids. Quite often we can do all the modeling we need with a spherical Earth. However, sometimes we find that we need to model the Earth with its proper oblate shape, so we them switch to the WGS84 geoid, or any one of its brethren. The price: all sorts of fun complexities. When I say I have a "forward/right/down" body rotation matrix, is the "down" vector towards the center of the earth, or is it perpendicular to the geoid? On a sphere, they're the same. On an oblate spheroid, I have to take the time to figure out which one was intended. If I don't take the time, then I might as well have just used a sphere.

And here is where I found it where it goes into greater detail:-

https://physics.stackexchange.com/questions/319909/why-does-nasa-need-an-aircraft-model-flying-over-a-flat-and-nonrotating-earth

I leafed thru the paper, not that I understand much of it, but I could not find mentions of flat Earth. And here is the kicker, earth is written in lower case. It is not "Earth".

EDIT: But yes, how the model in paper differs from others I haven't got a clue. I can't read that stuff.

Whatever "point," you wish to derive from the fact the word "earth," is written in lower case when accompanied by the adjective "flat," I believe is moot.

The word "earth," also is lower case when referencing terms such as "axis." North and East are also written in lower case and not capitalized.

I did a search so this is simply cut and paste:-

All models are wrong. Some are useful.

These days there's a popular trend when simulating things to simulate every possible mechanism we can imagine. Those who think that way would agree with you. Why would you ever make a flat Earth model when everything is eventually going to make its first flight on a real rotating spherical-ish Earth?

This approach works great until you come across real development or computational limits. The cited paper is from 1988. Computers were much weaker back then. For perspective, the Cray Y-MP was sold that year. Its peak performance was 333 megaflops. She cost $15 million dollars. Contrast that to today. A Geforce GTX 1070 is capable of 6,500,000 megaflops (6.5 teraflops) and has a price tag of around $400.

In those days, you didn't waste computational power on frivolities. It turns out that for a vast array of aeronautical problems, the effects of a flat earth vs. round are minimal (much less the effects of rotating vs. not). If you're shooting a shell 15km, and need it to land with pinpoint precision, you need all that extra complexity. However, many aero problems include a guidance unit which would address any error due to Coriolis effects or the spherical ground the same way it would handle any other errors. It'd simply see it wasn't on the right path and make a correction. The other sources of error here, such as winds, play a far larger effect in deviations from a flight plan, so all the rotating and spherical effects can just get lost in the noise.

Even today, we still make flat Earth models. The reason is not computation time, like it was in 1988, but development time. The more things you model, the more things you need to develop, verify, and maintain. If a particular problem does not call for advanced models, why waste budget developing and maintaining them?

A real life example of this shows up in geoids. Quite often we can do all the modeling we need with a spherical Earth. However, sometimes we find that we need to model the Earth with its proper oblate shape, so we them switch to the WGS84 geoid, or any one of its brethren. The price: all sorts of fun complexities. When I say I have a "forward/right/down" body rotation matrix, is the "down" vector towards the center of the earth, or is it perpendicular to the geoid? On a sphere, they're the same. On an oblate spheroid, I have to take the time to figure out which one was intended. If I don't take the time, then I might as well have just used a sphere.

And here is where I found it where it goes into greater detail:-

https://physics.stackexchange.com/questions/319909/why-does-nasa-need-an-aircraft-model-flying-over-a-flat-and-nonrotating-earth

Again, this not really an answer to the question.

As a matter of fact, it is a highly disingenuous effort to push the whole topic to the back burner by some RE-tard!

Merely pointing out that your question had been answered before in another forum

Quote from: rvlvr on March 01, 2018, 08:54:09 AM

I leafed thru the paper, not that I understand much of it, but I could not find mentions of flat Earth. And here is the kicker, earth is written in lower case. It is not "Earth".

EDIT: But yes, how the model in paper differs from others I haven't got a clue. I can't read that stuff.

Whatever "point," you wish to derive from the fact the word "earth," is written in lower case when accompanied by the adjective "flat," I believe is moot.

The word "earth," also is lower case when referencing terms such as "axis." North and East are also written in lower case and not capitalized.

You are right, and I am wrong.

I have thought "Earth" refers to our planet, and "earth" is, well, like the ground we walk on and so on. I blame this on not being a native speaker, but it does not in any way mean I was less wrong.

Just for you special RE-tards out there (this includes most of you by the way), please also pay attention to the adjective "constant," next to mass.

That ain't possible according to science either...

Why is NASA engaged in such shamanism!?!?

Quote from: totallackey on March 01, 2018, 09:03:06 AM

Quote from: rvlvr on March 01, 2018, 08:54:09 AM

I leafed thru the paper, not that I understand much of it, but I could not find mentions of flat Earth. And here is the kicker, earth is written in lower case. It is not "Earth".

EDIT: But yes, how the model in paper differs from others I haven't got a clue. I can't read that stuff.

Whatever "point," you wish to derive from the fact the word "earth," is written in lower case when accompanied by the adjective "flat," I believe is moot.

The word "earth," also is lower case when referencing terms such as "axis." North and East are also written in lower case and not capitalized.

You are right, and I am wrong.

I have thought "Earth" refers to our planet, and "earth" is, well, like the ground we walk on and so on. I blame this on not being a native speaker, but it does not in any way mean I was less wrong.

Well, I did too, but it seems it is not treated as such in this paper.

So your point wasn't for debate.

But then what was it for?

Why don't you tell us what you think it means then!

Merely pointing out that your question had been answered before in another forum

And I merely pointed this question has not been answered in any forum, oincluding the one you referenced.

That entire copy/pasta you presented is NOT an answer to the question.

It is a shitpost designed to placate/shuffle aside the reality of the issue because the person making the post had no fucking idea what else to do.

Not sure what is so impossible about using "constant mass" for construction of a model

Quote from: Cahaya on March 01, 2018, 09:06:32 AM

Merely pointing out that your question had been answered before in another forum

And I merely pointed this question has not been answered in any forum, oincluding the one you referenced.

That entire copy/pasta you presented is NOT an answer to the question.

It is a shitpost designed to placate/shuffle aside the reality of the issue because the person making the post had no fucking idea what else to do.

You mean it doesn't give the answer you want it to?

So your point wasn't for debate.

But then what was it for?

Why don't you tell us what you think it means then!

I think it is NASA acknowledging the reality of the Earth.

That it is flat and non-rotating.

Quote from: totallackey on March 01, 2018, 09:12:37 AM

Quote from: Cahaya on March 01, 2018, 09:06:32 AM

Merely pointing out that your question had been answered before in another forum

And I merely pointed this question has not been answered in any forum, oincluding the one you referenced.

That entire copy/pasta you presented is NOT an answer to the question.

It is a shitpost designed to placate/shuffle aside the reality of the issue because the person making the post had no fucking idea what else to do.

You mean it doesn't give the answer you want it to?

No.

I mean it does not give a fucking answer at all.

Quote from: Cahaya on March 01, 2018, 09:13:29 AM

Quote from: totallackey on March 01, 2018, 09:12:37 AM

Quote from: Cahaya on March 01, 2018, 09:06:32 AM

Merely pointing out that your question had been answered before in another forum

And I merely pointed this question has not been answered in any forum, oincluding the one you referenced.

That entire copy/pasta you presented is NOT an answer to the question.

It is a shitpost designed to placate/shuffle aside the reality of the issue because the person making the post had no fucking idea what else to do.

You mean it doesn't give the answer you want it to?

No.

I mean it does not give a fucking answer at all.

Well I disagree, almost the point of a debate wouldn't you say? I think it clearly answers the issue

I've emailed an authority on NASA reports and will post any reply I receive

I've emailed an authority on NASA reports and will post any reply I receive

LMMFAO!!!

"An authority on NASA reports..."

FUCKING COMEDY GOLD!

Quote from: markjo on March 01, 2018, 08:23:28 AM

It's called "defining the scope of the model".  Some models may include the shape and movement of the earth (probably for navigation purposes).  This is simply to note that the model described isn't one of those.

Why define a scope of a model for something that, according to science, is absolutely not true?

Probably for the same reason that concepts like Newton's laws of motion are initially taught using a friction free environment: to make the math simpler.

Quote from: Cahaya on March 01, 2018, 09:23:25 AM

I've emailed an authority on NASA reports and will post any reply I receive

LMMFAO!!!

"An authority on NASA reports..."

FUCKING COMEDY GOLD!

Glad I amused you