Why do airplanes have machinery to tell whether they are parallel to the ground?

Oh look
An undebiably straight saw blade made a circle.


https://youtube.com/shorts/BhgXIRmlSTA?si=Vo6Q7xniokgff82H

If there really were ‘curvature’, that measures at a rate of 8” per mile, squared, we certainly would have measured for it, ages ago, and more and more precisely since then, up to now, if it ever existed at all.

We have instruments which measure for the slightest curving or slope or imperfection on the surface, it’s not unknown or invisible or undetected!

As I told you before, which you all ignored, is that laser levels are tested for their accuracy of measuring for level over distances.

The only way they can DO that, is if they know and set up targets that ARE level over these distances, from the laser level to the targets, which both must be set at the same exact height above the surface, to measure its accuracy over that distance, and other distances too.

And lasers emit a perfectly straight beam of fine light over distances, they couldn’t measure for any sort of curvature, anyway, if it did exist at all.

Using straight beams of light, to measure for level, which is flat and horizontal across distances, on the surface, or above it, etc.

You’ve got an unseen, unmeasurable curve that doesn’t exist, is entirely made up, and sold to us as being real, and true!

Again, care to be honest for once in your life and address the blatant lies you have been making when you claim planes must descend?
Again, an equivalent argument can be made to show they must ascend.
This demonstrates that both arguments are pure BS.
Can you be honest for once, show a tiny shred of integrity and address this fact?
Admit your claim was pure BS or defend it.
Stop with the pathetic deflections to laser levels.

If there really were ‘curvature’, that measures at a rate of 8” per mile, squared, we certainly would have measured for it, ages ago, and more and more precisely since then, up to now, if it ever existed at all.

And we have, repeatedly.
You just ignore all that because it doesn't fit your delusional fantasy, and appeal to instruments which are not precise and accurate enough to measure the curve to pretend it isn't there.

We have instruments which measure for the slightest curving or slope or imperfection on the surface

No, we don't.
That is a blatant lie.
ALL instruments have a limit of precision. All instruments have some error.
So if the curve or slope or imperfection is slight enough, i.e. small enough) the instrument wont be able to detect it.
The only question is how accurate it is.

As I told you before, which you all ignored, is that laser levels are tested for their accuracy of measuring for level over distances.

Lying will not save you.
I have addressed this many times.
Laser levels have a limited range and a limited precision. So far the best one you have found is NOT ABLE TO MEASURE THE CURVE!
It is not precise enough to do so.
I have also explained what their accuracy is based upon, their ability to self level.
If you bother looking at the data sheets, they don't have measured inaccuracies for a bunch of different distances. Instead they have a rate, based upon an angle.

You’ve got an unseen, unmeasurable curve that doesn’t exist, is entirely made up, and sold to us as being real, and true!

No, we have a repeatedly seen, repeatedly measured curve which does exist, which is based upon reality.
Conversely, you have a magical flat surface which is never seen at long distance, never measured at long distances, and is entirely made up; with you needing to resort to so much dishonest BS to pretend it is real; and fleeing from that BS when it is refuted, only to bring it up again later. Just like you have done with laser levels, where you brought it up and were entirely refuted, you then fled from the discussion only to bring it up again now.

Again, all you are doing with these tactics is showing how dishonest and desperate and pathetic you and your position are.

We measure objects for surface flatness to a micron, over miles of surfaces, and account for diffraction, etc.

If we are able to account for diffraction, for example, as a known factor to account for in surveying land, they’d certainly account for your ‘curvature’ too.

No need to account for something that doesn’t even exist at all, like your made up ‘curvature’, that’s why they don’t

If there really were ‘curvature’, that measures at a rate of 8” per mile, squared, we certainly would have measured for it, ages ago,

Like this?


https://flatearth.ws/al-biruni-method





Again…

Quote from: sceptimatic on November 22, 2023, 09:24:43 PM

You're trying to use a curve and offer it as a straight-line perception and pretending that somehow covers what you're trying to portray Earth as which you have absolutely no idea about except to reference drawn graphs as some kind of proof offering.

Shrugs…


Measures “flat” with a straight edge with a small frame of reference.



The tank actually is big enough to have a gentle curve.



What should the curve look like to a person 6 foot tall for an earth 30,000 times, or more, greater in diameter than the tank?



https://flatearth.ws/horizon-dip

Didn’t Jack school you on that 8 inch thing? Anyway…

Debunking Flat Earthers 8 inches/mile squared - Irrelevant formula that both sides get wrong

mmmmmmm geometry says no



https://cdn1.byjus.com/wp-content/uploads/2021/04/types-of-polygons1.png

https://cdn1.byjus.com/wp-content/uploads/2021/04/types-of-polygons1.png

Not sure what you're trying to offer to back up your fictional globe.

Sceptic, he isn't trying. He IS using a curve and offering it as a straight line perception, just as you see when you look at the horizon out at sea.

Of course he can offer it as a straight line but it's never going to be a straight line, so he's never offering reality, only a pretence. That's the issue.
And the horizon has always been a theoretical line.

It is a drawn graph and it is a proof offering for the globe Earth.  Flat Earth destroyed with two lines.

Line drawing offers nothing for Earth and you know this so all you're doing is destroying your own ideals.

This is just TOO easy. Tell me I'm wrong, Sceptic.

It is fairly easy to show you're wrong.

I am demonstrating the dishonest trickery you use.

You are demonstrating the trickery you people use.

And you are confirming the general dishonesty of FEers where you now pretty much entirely ignore what is said to just go and claim pure BS.

Again, what the above clearly demonstrated is that if you view a sufficiently small enough section of a large enough curve, you cannot tell it is curved.

If you can't see a curve you can't claim a curve. If you do see what you believe may be a curve you have to physically verify it it.
None of this can be done over the vastness of Earth.
It can be done to show it's flat and water alone solves that, plus flying aircraft, as this topic is about.

Yet that doesn't stop dishonest FEers from using such trickery, taking a tiny portion of Earth and boldly proclaiming the entire Earth must be flat because they can't tell it is curved.

As above.

According to dishonest FE trickery, that circle is a straight line, because if you look at a tiny portion you cannot see the curve.

No. You've decided this, not flat Earthers or alternate Earthers.

Conversely, REers use actual evidence of curvature, such as how objects are obscured by Earth as they go past the horizon, and mountains of more evidence.
Things FEers cannot explain with a FE.

You don't use actual evidence of anything of the sort.
There's nothing you can physically offer to prove your globe. You know this and so does anyone else.

Quote from: sceptimatic on November 22, 2023, 09:24:43 PM

You're trying to use a curve and offer it as a straight-line perception and pretending that somehow covers what you're trying to portray Earth as which you have absolutely no idea about except to reference drawn graphs as some kind of proof offering.

Shrugs…


Measures “flat” with a straight edge with a small frame of reference.



The tank actually is big enough to have a gentle curve.



What should the curve look like to a person 6 foot tall for an earth 30,000 times, or more, greater in diameter than the tank?

Put your spirit level on that same curve as horizontal as if you were going to roll that big tank.
Place your level on it and keep that level bubble centred as you move the level and see if it curves around that tank or if it quickly leaves the tank in a straight line.
Trying to use a tiny level on a few corrugations is fine to offer a pretence of straightness but the immediate movement would kill it, as would a slightly bigger level or a stick.

They're called spirit levels for a reason, not spirit curves.

Now imagine flying a plane over a curve. You get the same thing. It would not follow it in level flight and your plane would leave an ever-widening gap between it and the surface, unless you moved the flaps to follow the contours, meaning you would be consistently in a downward dive, no matter how small that dive was.

Try again.

Put your spirit level on that same curve as horizontal

Your stupid.

The “spirit” level has nothing to do with what is being conveyed.

The straight edge is what is used.  The small frame of reference against the gentle curve of the large tank shows “flat”.

While your argument has to totally ignore the dipping try horizon.


So as you sceptimatic, you’re just trying to change the argument, you ignore context, and just ignore reality.

You’re just dogmatic and fail to provide any useful evidence that is from the real world. 

Lasers are used in precise surgical procedures, like on our eyes, etc.

When they talk about their accuracy, it is a degree of accuracy at a certain distance, the maximum distance within a range of accuracy.

They are much more accurate at closer distances than the maximum stated for them.

Do you think that laser levels cannot accurately measure for level over one mile, or over half a mile?

NASA has said that they have pointed lasers at their little ‘reflectors’ on the moon, and bounced back to them. If so, they would be incredibly accurate, to a much much longer distance that you believed them to be!!

To hit a target thats about one foot square with a laser pointed at it from 1/4 million miles away, and bounce right back to them, would take an extremely precise laser, no doubt.

It’s all fake, of course, but you believe it’s true, so how are laser levels not accurate enough to measure level over one mile or a half mile? 

Laser levels use a fine, focused light beam, which is a straight line of light, and the best ones today, are extremely accurate over a long distance.

They could not know how accurate they are, within a small range of error, at maximum, without knowing and setting up a target which is perfectly level to the laser pointing out to it. 

So they would certainly have to account for the ‘curvature’ over those distances, even if it were a fraction of an inch or a few mm, then!

They clearly don’t account for any ‘curvature’ at all.

Place your level on it and keep that level bubble centred as you move the level and see if it curves around that tank or if it quickly leaves the tank in a straight line.

WTF?

You are an idiot.

The straight edge is going to show deviation from flat.  The buble only shows how un-perpendicular to the right angle to gravity. 

Lasers are used in precise surgical procedures, like on our eyes, etc.

Which has nothing to do with the dip of the horizon.

Care to address what is actual posted?

If there really were ‘curvature’, that measures at a rate of 8” per mile, squared, we certainly would have measured for it, ages ago,

Like this?


https://flatearth.ws/al-biruni-method

To hit a target

Speaking of targets…

Proof of Earth Curvature: The Rainy Lake Experiment

http://walter.bislins.ch/bloge/index.asp?page=Proof+of+Earth+Curvature%3A+The+Rainy+Lake+Experiment

Summary
http://walter.bislins.ch/bloge/index.asp?page=Rainy+Lake+Experiment%3A+Conclusion

All data and observations agree with the predictions of the Globe Model, which includes Terrestrial Refraction. The predictions for the Flat Earth Model, however, contradict the observations.

The Rainy Lake Experiment shows even better than the Bedford Level Experiment that the earth is a globe, since we also have GPS measurements that are not influenced by Refraction or Perspective, but are of a pure geometric nature. GPS measurements directly provide the radius of the earth.

Only one conclusion remains:

The earth cannot be flat, but is a globe with a mean radius of 6371 km!

Simply seeing the buildings in Chicago or Toronto from over 40 or 50 miles away, when any ‘curvature’ over that distance would curve them down and out of our view, 100s of feet curving down by then, but they are still in view, except for the bottom, due to perspective.

This proves there is no ‘curvature’ right there, in fact

Quote from: DataOverFlow2022 on November 23, 2023, 04:06:24 AM

Quote from: sceptimatic on November 22, 2023, 09:24:43 PM

You're trying to use a curve and offer it as a straight-line perception and pretending that somehow covers what you're trying to portray Earth as which you have absolutely no idea about except to reference drawn graphs as some kind of proof offering.

Shrugs…


Measures “flat” with a straight edge with a small frame of reference.



The tank actually is big enough to have a gentle curve.



What should the curve look like to a person 6 foot tall for an earth 30,000 times, or more, greater in diameter than the tank?

Put your spirit level on that same curve as horizontal as if you were going to roll that big tank.
Place your level on it and keep that level bubble centred as you move the level and see if it curves around that tank or if it quickly leaves the tank in a straight line.
Trying to use a tiny level on a few corrugations is fine to offer a pretence of straightness but the immediate movement would kill it, as would a slightly bigger level or a stick.

They're called spirit levels for a reason, not spirit curves.

Now imagine flying a plane over a curve. You get the same thing. It would not follow it in level flight and your plane would leave an ever-widening gap between it and the surface, unless you moved the flaps to follow the contours, meaning you would be consistently in a downward dive, no matter how small that dive was.

Try again.

Why not keep the spirit level level on the tank, and roll the tank? It will remain level.

Planes do follow the curve of the Earth in level flight, Scepticmaniac. It's been explained to the likes of you a million fucking times.

Simply seeing the buildings in Chicago or Toronto from over 40 or 50 miles away, when any ‘curvature’ over that distance would curve them down and out of our view, 100s of feet curving down by then, but they are still in view, except for the bottom, due to perspective.

This proves there is no ‘curvature’ right there, in fact

Sigh.

Where you can see the top of the Chicago buildings across the lake from the top of a 200 foot tall hill.  And how much of the buildings you can see is dependent on the weather and amount of refraction?

Four cases together show beyond a reasonable doubt the earth is curved

https://www.theflatearthsociety.org/forum/index.php?topic=91626.0

Part one. First refraction. 

Refraction over simplified leads to how much of a distance target can be seen through mirage.  The new well known example is Chicago.

Quote

Skyline Skepticism: The Lake Michigan Mirage

https://www.abc57.com/news/mirage-of-chicago-skyline-seen-from-michigan-shoreline

To those that doubt affects of refraction. The full Chicago skyline should be visible all the time if it weren't the case, barring clouds, rain or fog. However that’s not the case, it is always changing. I encourage anyone to go look for themselves.

Flat earther’s ignore certain factors when using the Chicago skyline.  Such as, the pictures used are often from Tower Hill.

Quote

The distance from Warren Dunes state park is about 53 miles across the lake to Chicago. Someone that’s six feet tall standing on the lake shore can only see about three miles to the horizon. If you climb to the top of Tower Hill (250ft) you can see almost 20 miles to the horizon

https://www.abc57.com/news/skyline-skepticism-the-lake-michigan-mirage

And atmospheric conditions that change the amount of atmospheric refraction will change how much of the Chicago’s skyline that can be seen.  Seen as in the visible length of buildings. 

Quote

On a normal sunny day, say in summer you can only see a dozen or so of Chicago’s tallest buildings from southwest Michigan. Yes, you can see Chicago, just not all of it.
“Anything more than that, especially when you get above 10 or 12, something's happening, because that's not usually there," Nowicki said.
That something is a strong temperature inversion, warmer air above colder air, that causes light to bend.
“A mirage is just a case of atmospheric refraction, it’s caused by the fact you have temperature variations in the atmosphere and these cause density variations.”  says Doctor Mark Rennie, an associate professor in areo-optics at the University of Notre Dame. “So literally the speed of light varies within the air. And this variation of the speed of light has the effect of bending light rays."

https://www.abc57.com/news/skyline-skepticism-the-lake-michigan-mirage

The fact you need to stand on a 250 foot hill, and the changing visibility of building lengths is strong evidence the earth is curved.    And refraction is a factor that can’t be ignored, and most be factored for. 

If you doubt refraction, do you believe this is a real double decker ship?




If the earth is flat, why must one climb a hill over 200 tall to see the tops of builds where the amount of how much height of the buildings that can be seen is based on how much refraction?

Perspective causes it.

Why do we see further out when higher on the surface, or above the surface?

A horizon is further out when we’re higher up.

And so the reverse is also true.

You cannot see as far out when near the ground as you can see when standing up, right?

Near the ground you see more of the surface rising up in the distance than you see when standing up.

It reaches up to a limit, where a horizon is formed. 

Perspective causes it.

BS, a good zoom lens should bring things into view.  It can’t, because it’s physically blocked by the curvature of the earth.  From a sunset, boat going over the horizon, the Chicago Sky line.  Perspective can’t physically block something from view to prevent a zoom lens from revealing hidden details you falsely pin on perspective. 


Why can’t you see the whole  Chicago sky line as in the bases of the buildings standing on the shore.

Vs having to climb a hill 200 plus feet tall to see the tops of buildings?  And it’s dependent on refraction?

Anyway..  proper context..

The distance from Warren Dunes state park is about 53 miles across the lake to Chicago. Someone that’s six feet tall standing on the lake shore can only see about three miles to the horizon. If you climb to the top of Tower Hill (250ft) you can see almost 20 miles to the horizon

https://www.abc57.com/news/skyline-skepticism-the-lake-michigan-mirage

If you stood on a 200 foot hill.


Without refraction on a curved earth, you could see the tops of buildings over 850 feet tall?

If you stood on a hill 250 feet tall.


At 53 miles away, on a curved earth, on a hill 250 foot tall, with no refraction.  You could see buildings over 760 feet tall.



The 10 th tallest building in Chicago is still 896 feet tall.


Anyway….


https://www.flickr.com/photos/ctm_800/3417439088/in/photostream/

Why can’t you see the bases of the buildings.  Why can’t you see all the building all the time.  Why does how many buildings you can see depend on observation height and amount of refraction.

Perspective causes it.

Sigh.  A lie that was debunked here.

Horizon did not block duck from view
https://www.theflatearthsociety.org/forum/index.php?topic=90722.msg2367945#msg2367945

Turbs, a thread you were part of.

Don’t you get tired of the same old lies Turbs.

Quote from: sceptimatic on November 25, 2023, 02:33:19 AM

Put your spirit level on that same curve as horizontal

Your stupid.

Don't call people stupid unless you use the right word to show that (hint) you're not projecting.

The “spirit” level has nothing to do with what is being conveyed.

The spirit level has everything to do with it or you wouldn't have used it.

The straight edge is what is used.  The small frame of reference against the gentle curve of the large tank shows “flat”.

Then why didn't you use a straight edge?
Let me guess, the tiny spirit level was all you had at the time and a length of timber or metal box section would've rendered the experiment useless.

While your argument has to totally ignore the dipping try horizon.

The horizon is theoretical and dipping nor elevation will render the theoretical horizon impossible from level vision.
Seeing as we always see it with level vision we cannot be flying over a globe, no matter how ou try to twist it.

So as you sceptimatic, you’re just trying to change the argument, you ignore context, and just ignore reality.

No, I pay attention to the argument and I simply point out the massive errors and twisting in it with this global nonsense.

You’re just dogmatic and fail to provide any useful evidence that is from the real world.

I provide plenty. What you take from it will be nothing because you're 100% indoctrinated into the global model, no matter how absurd it is.
You're welcome to do that of course but you will never be correct.

Quote from: sceptimatic on November 25, 2023, 02:33:19 AM

Place your level on it and keep that level bubble centred as you move the level and see if it curves around that tank or if it quickly leaves the tank in a straight line.

WTF?

You are an idiot.

The straight edge is going to show deviation from flat.  The buble only shows how un-perpendicular to the right angle to gravity.

The straight edge will massively show deviation from flat but using a tiny level and con people into believing a curvature is level and flat is laughable.

Go and get a larger level or a larger straight edge and do this again and let's see what happens.

Why not keep the spirit level level on the tank, and roll the tank? It will remain level.

Nice try at twisting it. This is what you people have to do.

Planes do follow the curve of the Earth in level flight, Scepticmaniac.

Planes follow a path along Earth at whatever altitude. They do not follow any curvature unless they angle to change direction or to land or take off.
Their artificial horizon shows you this.

It's been explained to the likes of you a million fucking times.

Using foul language will not make your argument valid.

Then why didn't you use a straight edge?

Yes.  You’re being an idiot.

This straight edge with a small frame of reference makes the curve of the tank look flat because the tank has  such a general curve because of its size.

Measures “flat” with a straight edge with a small frame of reference.



The tank actually is big enough to have a gentle curve.


sceptimatic, why are you trying to change the subject from such a simple truth?

It does make you look like an idiot.

Now, part two of the argument.

What should the curve look like to a person 6 foot tall for an earth 30,000 times, or more, greater in diameter than the tank?

Their artificial horizon shows you this.

Walk us through this for the artificial horizon indicator as an airplane passes over an ever increasing horizon as it flys towards the increasing slope and horizon of a mountain range?


Anyway…

https://flatearth.ws/artificial-horizon

An artificial horizon, or attitude indicator, is a flight instrument that indicates the aircraft’s orientation relative to Earth’s horizon and gives an immediate indication of the smallest change of orientation. An artificial horizon utilizes a gyroscope to detect the change of orientation and pendulous vanes to continuously correct the orientation relative to the level.

Flat-Earthers claim that an artificial horizon should drift over time if the airplane is flying over the spherical Earth because the gyroscope will eventually drift and no longer points toward Earth’s center. In reality, an artificial horizon has a self-correcting mechanism, keeping the gyroscope upright if it is displaced for any reason, including by the aircraft’s motion following Earth’s curvature.

Preflight Actions:
When an aircraft engine is first started and pneumatic or electric power is supplied to the instruments, the gyro is not erect
A self-erecting mechanism inside the instrument actuated by the force of gravity applies a precessing force, causing the gyro to rise to its vertical position
The attitude indicator should not bank more than 5° in taxi turns

https://www.cfinotebook.net/notebook/avionics-and-instruments/attitude-indicator

Attitude indicators have mechanisms that keep the instrument level with respect to the direction of gravity.

https://en.m.wikipedia.org/wiki/Attitude_indicator

Flat Earth - Yes an aircraft Artificial Horizon self corrects in flight - Pt 1

Their artificial horizon shows you this.

The vacuum powered instruments that uses gravity?


🤣🤣🤣🤣🤣🤣🤣🤣

Pendulous Vanes | Pilot Tutorial



Ep. 60: Inner Workings of an Attitude Indicator | Gyroscope


Like this source better…

https://www.aopa.org/training-and-safety/students/presolo/special/understanding-gyroscopic-instruments

Gyro instruments react to short-term movements of the airplane. In fact, the attitude indicator contains a set of weights intended to drive the instrument toward level flight by sensing gravity. These weights move the instrument face about 3 degrees per minute. So if you were to maintain a 30-degree coordinated banked turn for 10 minutes,


Commonly, the AI and HI are powered by vacuum pneumatic systems.

Flat Earthers still don't understand how an Artificial Horizon works - read comments please.

Not sure what you're trying to offer to back up your fictional globe.

You mean the very real globe you are yet to show a fault with.

Of course he can offer it as a straight line but it's never going to be a straight line, so he's never offering reality, only a pretence. That's the issue.

No, the issue is how a curve will appear straight if you view a small enough portion of it.

I clearly demonstrated how a small enough portion of a large enough curve will appear straight.
Yes, it is NOT a straight line. The point is YOU CANNOT TELL if you are looking at a small enough portion of it.
So the dishonest FEers claiming Earth must be flat because they can't see the water curve in their sink are blatantly lying to everyone, pretending a curve is straight.

And the horizon has always been a theoretical line.

No, it has always been a physical line.
The theoretical horizon has been in drawing, where people take the lazy option and pretend it is infinitely far away.

It is fairly easy to show you're wrong.

Then why are you completely incapable of doing so and need to resort to deflection and lies?

You are demonstrating the trickery you people use.

No, I'm demonstrating the trickery YOU people use, dishonest FEers.
You take an observation of Earth where you cannot see the curvature because you do not have an accurate and precise enough device to do so; and then dishonestly use that to pretend Earth is flat.
And that is exactly what I demonstrated. Taking a tiny portion of a circle, so you cannot tell it is a circle, and showing how it looks like a straight line.
And then I exposed it, by showing how it is actually a circle.

This is the dishonesty YOU use.

REers do not do this.
Instead, they appeal to things like objects obscured by the horizon clearly showing a curve.
Or countless other observations which work with a curved Earth and require so much convoluted BS and wishful thinking, requiring nature itself to be conspiring against us to pretend it would work on a FE.

The time REers bring up this straight line is to refute the lies of dishonest FEers like yourself.
We bring it up when lying FEers claim that you should always be able to see a curve, no matter how slight.
We bring it up when lying FEers claim that Earth must be flat because they can't measure/observe a curve, when they make no attempt to demonstrate they would be able to do so over such a short distance.

So no, this is trickery entirely by your side. We bring it up to expose this dishonesty of yours.

If you can't see a curve you can't claim a curve.

We can see a curve. As clearly demonstrated by mountains of evidence showing this curve.
We are not presenting this curve appearing straight to claim Earth is curved. We are presenting it to expose your lies.
It is not an argument put forward in favour of a RE. It is an argument put forward to refute your lies.
Stop pretending it is an argument to prove a RE.

None of this can be done over the vastness of Earth.

Except it has been done, repeatedly.

It can be done to show it's flat and water alone solves that, plus flying aircraft, as this topic is about.

Except, as clearly demonstrating, including by the above, IT DOESN"T!

The fact that you can be above water level and look towards an object above water level, yet have water obscure the bottom of the object clearly indicates water IS NOT FLAT!

Again, you are appealing to the exact dishonest trickery demonstrated above.
You look at water in your sink, can't see the curve, and use that to boldly proclaim the surface of water must be flat; which is pure BS.
Your observation in your sink cannot tell if water will be flat or curved over 10s of km.
And again, this is just further demonstrating your dishonesty.
You blatantly lie to everyone by claiming it is our trickery, while using the exact trickery that is being discussed.
Your dishonesty knows no bounds.

But observations of distant objects, with water obscuring the bottom of the object, even though both the observer and object are at a greater elevation than the water clearly demonstrates it DOES curve.

So water alone shows you are wrong.

No. You've decided this, not flat Earthers or alternate Earthers.

No, I haven't.
This thread has been about that, about claiming that planes should magically be able to measure the curved path they are following, and because they don't it magically proves Earth is flat.
You have done it repeatedly, by appealing to water as if it is flat, even though you have no evidence of that except tiny observations where you cannot tell.

You don't use actual evidence of anything of the sort.
There's nothing you can physically offer to prove your globe. You know this and so does anyone else.

Repeatedly lying will not save you.
I provided examples of evidence in that quote which you just entirely ignore.
Again, objects disappearing from the bottom up as they go over the horizon is evidence of curvature.

Meanwhile, what do you have to pretend Earth is flat? Observations where you cannot tell if it is flat or curved, i.e. the very trickery being discussed; as well as blatant lies.

And yet again you flee from the topic, the simple lie you repeatedly claimed and had repeatedly refuted.
Again, when will you show even a single shred of integrity and admit to spouting pure BS to try to back up your flat Earth fantasy or do the impossible and defend your blatant lie?

Again, why should planes magically need to descend to stay level?
Remember, any argument you present for this MUST deal with the equivalent argument which would indicate they need to ascend.
Focusing on only one of those is just further dishonesty.

We measure objects for surface flatness to a micron, over miles of surfaces, and account for diffraction, etc.

Prove it.
The only times I have heard of anything close to that would be for things like LIGO, which had to account for curvature.

If we are able to account for diffraction, for example, as a known factor to account for in surveying land, they’d certainly account for your ‘curvature’ too.

And they do, in large distance surveying.

When they talk about their accuracy, it is a degree of accuracy at a certain distance, the maximum distance within a range of accuracy.
They are much more accurate at closer distances than the maximum stated for them.

You could just leave it as degree, as it is about ANGLES!
That means the linear measurement will depend upon distance.
That is also why they are often quoted as a gradient, e.g.  1mm per 100 m.

Do you think that laser levels cannot accurately measure for level over one mile, or over half a mile?

If you think there is one, why not provide it?
Most do not have the range to measure that far.
And as repeatedly shown, their accuracy within their range cannot account for the curve.
If you think there is a better one, PROVIDE IT!

NASA has said that they have pointed lasers at their little ‘reflectors’ on the moon, and bounced back to them. If so, they would be incredibly accurate, to a much much longer distance that you believed them to be!!

No, it wouldn't.
Not in the slightest.
You have had this delusional BS of yours refuted before. Why bring it up again?

If you would like a similar example, consider a car headlight when you driving down the street and illuminate one of the highly reflective surfaces.
Does that require you to carefully point your light at it? NO!
The same applies here.

All they need is for the laser to hit the retroreflector. It doesn't matter how wide the beam is.

And all laser beams diverge.
They are limited in their precision based upon their width, just like the angular resolution of a lens is limited.
If you want to be accurate to 1 m at 350 000 km, with a laser with a wavelength of 400 nm, you need a laser that is 170 m wide.
If you have it any narrower than that, it will diverge so it hits an area much larger than 1 m.
If you had a laser beam that was 1 m wide, by the time it reaches the moon, it would spread out to a size of 170 m wide.
And that is if it was perfect.
With things like the atmosphere scattering it and so on it is far more likely to spread out to several km wide.

So no, it does NOT need to be incredibly precise.

This is also why the return signal is so low.

It’s all fake, of course

Your arguments certainly are.

They clearly don’t account for any ‘curvature’ at all.

Based upon what? Your wishful thinking?

Simply seeing the buildings in Chicago or Toronto from over 40 or 50 miles away, when any ‘curvature’ over that distance would curve them down and out of our view, 100s of feet curving down by then, but they are still in view, except for the bottom, due to perspective.

This proves there is no ‘curvature’ right there, in fact

Wrong again.
In fact, you couldn't be further from the truth.
Even if we ignore refraction and place the observer at sea level, over 40 archaic units, the drop is only ~1000 archaic units.
The CN tower is almost double that height.

If Earth was flat, you would see the entirety of the building, just smaller. There is no reason for the bottom to be magically hidden if Earth was flat.
If Earth was flat, if you were able to resolve a 5 m section of the tower at the top, you should be able to do so at the bottom, and see the bottom of the tower.
The tower should appear to be a shrunk down version, still above the water.

But for a RE, you would expect to see the top, but the bottom hidden, obstructed by the curve.
It should appear as if the tower has sunk into the water.
And that is what we do see.

If you are on a hill, or there is significant refraction, you will see more of the tower.

So rather than disproving a curve, these observations PROVE a curve.

Perspective causes it.

No, it doesn't.
Perspective doesn't magically hide the bottom the objects.
It doesn't magically make them appear to sink below eye level.
Instead, it makes them appear smaller and closer to eye level.
No amount of perspective will hide the bottom of an object above sea level, or make it appear to sink into the water.

Why do we see further out when higher on the surface, or above the surface?

Because Earth is round, as explained repeatedly.

When I am above a flat surface, I can see to the edge of that surface, as there is nothing obstructing the view.
When I am in a straight corridor, I can see to the end of that corridor as there is nothing obstructing the view.
But when I am on a curved surface, or in a curved corridor, the curve blocks the view. As I get further from the curve I can see further.

This has been explained to you repeatedly. Stop playing dumb.

The higher you are above a RE, the further you can see.
So yet again, you are proving there is curvature.

It reaches up to a limit, where a horizon is formed.

And this limit is where curvature starts to beat perspective.
The effect of curvature makes it appear to sink, while perspective makes the ground appear to rise.

For a FE, there is no limit. The ground continues to rise at an ever decreasing rate.
For a RE, as the surface is actually going down, it eventually starts to appear to go down.

Again, you have had this explained to you before.
Again, all you are doing now is proving Earth is round.

For a FE, there should be no limit. You should be able to see to the edge, or until a mountain or the like obstructs your view.
For a RE, there should be a limit, and that limit depends upon your height.

Put your spirit level on that same curve as horizontal as if you were going to roll that big tank.
Place your level on it and keep that level bubble centred as you move the level and see if it curves around that tank or if it quickly leaves the tank in a straight line.

And more blatant dishonesty.
Will you also be rolling the tank to keep the direction of down consistent? Or are you just using the standard dishonest FE BS or pretending there is a magical universal down?

Earth is not a tiny ball on top of a much larger ball. It is in free fall, well outside the Roche limit of any larger mass.

Related to this, what is the top of the tank?
The point opposite Earth.
So what is the "top" of Earth? The point opposite what?

For Earth, there is no top.
You have down towards the centre and up away from the centre (approximately anyway).
So if you kept that tank oriented so the spirit level is at the top (to honestly simulate Earth) and rolled the tank along under the spirit level, you would not notice a curve between the tank and spirit level.

They're called spirit levels for a reason, not spirit curves.

Yes, because they measure LEVEL, i.e. the direction perpendicular to down.
Notice that they aren't called spirit flats?

Now imagine flying a plane over a curve. You get the same thing.

Yes, the same thing, where the curvature is insignificant and not able to be detected.

you would be consistently in a downward dive, no matter how small that dive was.

No, you wouldn't
Again, this is simply demonstrated by considering a round trip.

You start at A, you travel to B and then turn around and go back to A.
According to your delusional BS you need to go down to get to B from A, and then you need to go down again to get back to A.
This means A must be lower than A, clearly showing your argument is pure BS.

Likewise, it is also shown to be BS by the fact you can consider it in the opposite direction. Instead of focusing on where the plane has to go, focus on where it has been, and falsely claim it needs to have gone up to reach where it is. That would mean it needs to be in a constant ascent. If you can equally argue for 2 opposite options then the argument is BS.

What the honest argument would be is the change in the attitude of the plane, i.e. it would need to rotate.
Assuming it is travelling at 1000 km/hr, along the equator, in the direction Earth is spinning so it also gets the 444 m/s from the rotation of Earth, then its total speed would be roughly 721 m/s. That equates to 0.0065 degrees per second.
That will NOT be noticeable.
That will NOT be measurable.
And more importantly, the plane is already adjusting its attitude to maintain level flight.
So these corrections needed will be insignificant. So again, your argument is BS.

The spirit level has everything to do with it or you wouldn't have used it.

All it provided was a straight edge, an edge which did not allow you to see the curvature of the tank.

That is what was being discussed.
But because that refutes your BS, you ignore it and deflect, trying to twist it into something else.

Let me guess, the tiny spirit level was all you had at the time and a length of timber or metal box section would've rendered the experiment useless.

Why do you keep playing dumb?
The point is that over a short enough distance YOU CANNOT TELL IT IS CURVED!

So yes, going to a much larger section of it would entirely defeat the point.
That is why dishonest people like you want to stick to water in your sink to pretend it is flat, rather than long distance observations which clearly show it is curved.

The horizon is theoretical

The horizon is real.
You not liking that will not change it.

Seeing as we always see it with level vision we cannot be flying over a globe, no matter how ou try to twist it.

You have had this dishonest BS refuted before. Why bring it back up?
We see it with "level vision" with a significant FOV.
If you limit the FOV enough, you don't see it with a level view.
It is observed and measured to be BELOW level.
And by an amount consistent with a RE.

It doesn't matter how you try to twist that, it shows you are spouting pure BS and shows Earth is round.

You want to dishonestly pretend that something 1 mm below eye level at a distance of 1 km, is magically out of your level view.

No, I pay attention to the argument

And then proceed to blatantly lie about it to avoid admitting you are wrong.

I simply point out the massive errors and twisting in it with this global nonsense.

You mean the honest and accurate portrayal which matches reality? The one with massive errors and twisting is you.

I provide plenty.

No, you don't.
You dishonestly deflect from the argument and bring up the same refuted BS, blatantly lying about reality to pretend Earth is flat.

What you take from it will be nothing because you're 100% indoctrinated into the global model, no matter how absurd it is.

Quite the opposite.
The clearly indoctrinated one here is you. You need to repeat the same refuted lies as if they haven't already been refuted. You refuse to see reason and just cling to your fantasy.
You dismiss the RE as absurd but cannot show any fault with it.
You resort to pathetic lies and trickery, and when it is exposed you claim it is the other side doing it, and will some times try to twist a refutation of your delusional BS into a positive argument for the RE so you can attack that strawman rather than admit you were spouting dishonest BS.

The straight edge will massively show deviation from flat

Only if it is big enough. If it is small enough, it wont. That is the point you keep ignoring.

but using a tiny level and con people into believing a curvature is level and flat is laughable.

Projecting again.
You are the one using a tiny area, like the water in your sink, to pretend level is magically flat; while ignoring large scale observations which show it isn't.

Their artificial horizon shows you this.

How?