1

Flat Earth Investigations / Re: Airplane proves flat earth ✈️

« on: August 25, 2025, 08:48:09 PM »

Thanks, I think I understand your explanation about autopilot, altimeters, and how flight routes are determined. It makes sense that small pitch changes due to earth’s curvature are negligible compared to turbulence and pressure differences, and that operational factors like airspace and winds play a bigger role in flight paths
I’ve seen some people claim that certain flight routes or autopilot behavior prove the Earth is flat. Given what you explained, it seems that most of these observations could be explained by air traffic rules, pressure settings, and operational choices. From your experience, is there anything in actual flight that could realistically be used to ‘see’ the curvature of the Earth?

Yes, lots. Radio navigation aids have limited range because of the curvature of the earth. Radios themselves have the same limitation, depending on frequency. As an ATC, I also see the same limitations but from the viewpoint of ground based radar not detecting low level traffic at 50nm range, but detecting high level traffic at 200nm.

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Flat Earth Investigations / Re: Airplane proves flat earth ✈️

« on: August 21, 2025, 08:49:43 AM »

I'm not claiming the instruments aren't calibrated, but I'm trying to understand, if the Earth is truly spherical, how do the flight instruments account for the curvature in their real-time calculations? For example, on long-distance flights, does the autopilot follow the curvature by continuously descending at a shallow angle, or does it rely entirely on the data from the waypoints?

Because they have been designed to do so. What sort of flight instruments are you talking about? (there are many different kinds on instruments!) Do you mean what is often referred to as the 'artificial horizon'?

In most stages of flight, for most aircraft where fitted, the auotpilot will be in ALT SEL/VNAV modes, which will maintain whatever level is set in the autopilot control panel. Aircraft altimeters are basically barometers, so will be following a constant preessure plane, of, say, 1013.2Mb (29.92in). Dialling in 30,000ft might, depending on local air pressure at the surface/sea level, result in an aircraft flying at 29,000ft or 31,000ft. The key is that all aircraft in the same area of sky are using the same pressure datum to reference (which is why we tell all deaprting and arriving aircraft at my airport the local air pressure for them to enter into their altimeters). None of this is dependent upon the shape of the earth.

Any minute change in pitch due to the curvature of the earth's surface will be drowned out by the relatively massive changes felt by the passengers due to changes in air pressure and turbulent air masses.

There are lots of flight routes that don't follow the great circle route. This can be for many reasons -

- Airspace restrictions - many nations reserve large areas of airspace for military exercises and training, and there are lots of no-go airspace areas due to conflict.
- Route charges - Majority of nations charge the operators of aircraft flying through their airspace, in order to generate revenue to provide the ATC service. Some countries' charges are expensive, some not so much. An airline may try to avoid flying through expensive airspace, even if it lengthens the flight. It's a balance of airspace cost v fuel cost.
- Winds - a longer flight with a tailwind may use less fuel than a shorter flight with a head wind.
- Airspace route structure - the published airways and routes that aircraft file on their flight plan -  In busy areas, these will be designed to spearate directional flows of traffic, to ensure orderly and safe operations (just like one lane of a road goes in one direction, the other lane the other direction). This can often not be the shortest flight route for an individual aircraft, but it allows the airspace to handle far more aircraft at one time than if all the aircraft just flew their shortest route. 
Lots of other factors too.

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Flat Earth Investigations / Re: Airplane proves flat earth ✈️

« on: August 20, 2025, 02:47:14 PM »

As an air traffic controller of 27 years experience, I know that flight planning, routing and airspace design are all based on the round earth. In my experience, the myriad factors that come into play both in terms of exact route planned, and exact route subsequently flown, by aircraft often confuse flat earthers.

Aircraft in flight are constantly adjusting. They would do so regardless of the shape of the earth.

What leads you to believe that instruments and navigation systems are not 'correcting for curvature in real time'? What instruments?

4

Flat Earth Investigations / Re: Circumnavigation World Record Sailing Discrepancies

« on: October 10, 2024, 04:24:06 AM »

Quite.

The winds in the southern ocean are anomolous only in the fact that they are, on average, stronger in relative terms to those normally found, on average, elsewhere.

We know exactly why this is the case. We can predict them.

It's disingenuous at best to claim or suggest that they are somehow mysteriously strong, and that humankind is continually surprised by them, therefore causing all sorts of odd flight times and sail voyage durations.

5

Flat Earth Investigations / Re: What is the true map of the earth?

« on: May 17, 2024, 07:49:45 PM »

As anyone who has any serious knowledge of aviation knows (air traffic controller for 25yrs here), there's a lot of inaccurate nonsense and claims.

Airspeed indicators are accurate and work fine. As do the varied GNSS and SBAS systems. The various jetstreams are well known, and although always active, strength and location does vary, although can usually be forecast. 'Southern winds' are only 'anomalous' in the sense they are usually very strong. We know why.

The document Tom keeps linking to as evidence of weird flight routes is a red herring, and again written by someone with a demonstrable lock of understanding of how global commercial aviation works.

Again, having been involved in the operational side of aviation for 25yrs, I would say the majority of 'travel' writers have no idea about operational matters, just like the majority of their readers. Airlines cancel flights for all sorts of reasons. For example, yesterday British Airways had cancelled 12 departures from London Heathrow by mid afternoon, out of 347 planned.

6

Philosophy, Religion & Society / Re: Trump

« on: February 14, 2024, 06:59:02 AM »

Quite a few people here who don't understand how NATO works, is funded, or the difference between state's own defence budgets and NATO contributions.

Nobody owes outstanding money to NATO. There are not a lot of unpaid NATO invoices lying around in offices in Europe.

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Flat Earth Media / Re: New line-of-sight sea level signal transmission record

« on: October 03, 2023, 05:13:06 PM »

Yes, I admit to some embarrassment about posting on an FE forum. 

Anywho, I worked with pilots on a daily basis; not sure where your experience is drawn from.  Good to know you hold them in such high esteem though, as most astronaut pilots are former fighter pilots,

Me too, pilots and ATCs. There’s a bell curve for any characteristic, and for pilots (especially military pilots) you’d expect that curve to be offset from the general population for certain characteristics, but there will still be outliers as in any sample. That surely isn’t news to anyone?

To be honest the text in that video seems like it’s written by a DCS (or even a Falcon 4!) gamer who’s done 2+2 and made 974.9.

8

Flat Earth Theory / Re: Altitude related g... where are the experiments?

« on: April 25, 2023, 05:31:48 PM »

There are lots of options to travel to the north pole. Not just one. Have a google/duckduckgo.

Surely by your definiton everywhere is restricted? Where are you drawing the line here?

Yes, and there are lots of options to travel to North Korea as well. You can even go to different parts of the country. All of them approved and pre-arranged by "The Great Leader" and his government. See? That proves that North Korea isn't as restricted as you think; it's only your imagination.

Why are you talking about N Korea?

You were making a claim about the North Pole, no?

Can you explain how travel to the North Pole is restricted please?

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Flat Earth Theory / Re: Altitude related g... where are the experiments?

« on: April 25, 2023, 12:33:54 PM »

There are lots of options to travel to the north pole. Not just one. Have a google/duckduckgo.

Surely by your definiton everywhere is restricted? Where are you drawing the line here?

10

Flat Earth Theory / Re: Curvature of the Horizon

« on: April 14, 2023, 04:59:29 PM »

Action80,

Please can you provide any evidence that backs up your view that 'it is fact' ...'that no one person can claim with certainty what it is they are looking at from such a distance away' and that 'Every seafarer and navigator know the traits of both mediums are identical in most instances when it comes to coloration'?

Well, I don't know how to be more clear on either point.

You've been clear as to what you believe, I wasn't asking you that, I'd like to understand what you're basing that view on. What evidence have you got? Is it recorded that people often confuse what they think is the horizon with something else? That the sea extends further up then they think, or the sky extends further down than they think?

There is no clear delineation.

You don't see a clear delineation on my photograph? I've marked it with the red arrow as to where I'm seeing one. The reflective sea, and the non-reflective sky. Does the area below the arrow, and the area above the arrow look the same to you?

11

Flat Earth Theory / Re: Curvature of the Horizon

« on: April 10, 2023, 08:08:39 PM »

Can you explain what you mean? Because I don’t think you have.

On a clear day with good visibility, the delineation between sea and sky is very easy to discern.

Have you lived on the coast? How often do you look out to sea on the average day?

Although I don't currently live on a shoreline of a major body of water, I have spent ample time there.

Fact of the matter is this: the traits of both mediums, such as color and reflectivity, are such that no one person can claim with certainty what it is they are looking at from such a distant point away.

Fact of the matter is?

Sorry, no, that’s your opinion.

No, it is fact.

Every seafarer and navigator would disagree.

Every seafarer and navigator know the traits of both mediums are identical in most instances when it comes to coloration.

Yes, at time, in poor visibility, one cannot distinguish the horizon. But on many other occasions it is very clear.

Are you saying that even when it is clear, you believe that the water continues on, effectively appearing above the horizon, but that it looks to us exactly the same as the sky?

I am saying no one knows what it is they are looking at from that distance.

Sorry, I've been away and busy with work.

Action80,

Please can you provide any evidence that backs up your view that 'it is fact' ...'that no one person can claim with certainty what it is they are looking at from such a distance away' and that 'Every seafarer and navigator know the traits of both mediums are identical in most instances when it comes to coloration'?

When you claim this, are you saying that:

- You can see what looks like a clear delineation in most conditions, but you are not sure if the sky extends below this
- You can see what looks like a clear delineation in most conditions, but you are not sure if sea extends above this
- You can't see a clear delineation at all

How far away does an object have to be to be at that 'distant point away' 'such that no one person can claim with certainty what it is they are looking at'?

For example, the lighthouse in my picture below, how far away would it have to be near to the horizon such that you are no longer confident it's a lighthouse?

12

Flat Earth Theory / Re: Curvature of the Horizon

« on: March 19, 2023, 07:11:50 AM »

There are multiple accounts of most RE adherents that curvature can be detected even at ground level

Do you have any relevant quotes from people to back this up?

An oldie but a goodie claim by AATW that no RE-er has ever claimed that curvature can be detected at ground level by the human eye...

yet...

Unsurprisingly, here he is (along with his choir) in this very thread, doing just that.

With all due respect, I’m not claiming anything about curvature in this thread. I’m taking issue with the blanket assertion that the horizon can never be clearly distinguished.

Posters on this thread should also be wary when they talk about curvature, are they talking in the sense of a curve appearing left to right as you look at the horizon, or in the sense of the curvature away from the observer that produces the horizon?

13

Flat Earth Theory / Re: Curvature of the Horizon

« on: March 19, 2023, 07:08:05 AM »

And on a clear day, with little swell or chop, lo and behold it’s still a clear line.

I really don’t understand how people can say it’s not.

You can keep making this false statement until the end of time (if you choose), but I have already pointed out why it is false.

Can you explain what you mean? Because I don’t think you have.

On a clear day with good visibility, the delineation between sea and sky is very easy to discern.

Have you lived on the coast? How often do you look out to sea on the average day?

Although I don't currently live on a shoreline of a major body of water, I have spent ample time there.

Fact of the matter is this: the traits of both mediums, such as color and reflectivity, are such that no one person can claim with certainty what it is they are looking at from such a distant point away.

Fact of the matter is?

Sorry, no, that’s your opinion.

Every seafarer and navigator would disagree.

Yes, at time, in poor visibility, one cannot distinguish the horizon. But on many other occasions it is very clear.

Are you saying that even when it is clear, you believe that the water continues on, effectively appearing above the horizon, but that it looks to us exactly the same as the sky?

14

Flat Earth Theory / Re: Curvature of the Horizon

« on: March 16, 2023, 11:18:39 AM »

And on a clear day, with little swell or chop, lo and behold it’s still a clear line.

I really don’t understand how people can say it’s not.

You can keep making this false statement until the end of time (if you choose), but I have already pointed out why it is false.

Can you explain what you mean? Because I don’t think you have.

On a clear day with good visibility, the delineation between sea and sky is very easy to discern.

Have you lived on the coast? How often do you look out to sea on the average day?

15

Flat Earth Theory / Re: Curvature of the Horizon

« on: March 16, 2023, 11:11:11 AM »

Yes, often times, the sea and sky are indistinguishable.  The other half of that equation is that often times the difference is like night and day. 

If you haven't observed this yourself, perhaps you need to get out more.

Whether or not I 'need to get out more," is not the point. You, nor anyone else for that matter, have zero ability to determine the precise conditions of any object from three miles away. Especially with the naked eye.

That's the point.

We weren’t talking about how far away the horizon was. We were saying that it was often very clear. Because it is. I can count on the fingers of one hand how many times a year I used to struggle to see a clear horizon in good visibility.

You couldn't plot with any accuracy the exact line of the horizon from 3 miles away. Even if you did manage to wade thogh the swell, waves, freak waves, refraction, haze, reflections.

And on a clear day, with little swell or chop, lo and behold it’s still a clear line.

I really don’t understand how people can say it’s not. I spent the first 18 years of my life looking at the horizon out to sea literally hundreds of times every day.

Do you live near the coast, SimonC?

Just because someone has done something for a number of years does not mean they have been doing it right. Practice doesnt make perfect. Practice makes permanent. My heating engineer had been using an old saw to cut coper pipe since he was an apprentice. He had no idea that modern day pipe cutters had been invented and carried on blissfully with his 'rough' and time-consuming jointing method.
Many people think/believe they can see a definite line of the horizon. But thats c.3 miles away. And is so fine that it isnt even the thickness of a piece of paper - and you couldnt see something that thin at 3 miles.

Not doing it right?

I’m looking at the horizon and can see a clear delineation of the sea and sky. It’s quite simple. I’m doing it right now, as I type. It’s not thin, it’s the boundary between sea and sky, as you look out.

If you hold two pieces of paper of different colours and overlap one on top of the other, there’s not a thin, invisible line separating them, it’s where the extent one of piece of paper stops, and the other continues behind, and therefore becomes visible. One large body is in front of another large body. On days of poor weather, where the visibility is low, the clear delineation is not there, the sea appears to gradually disappear into the mist.

How you often looked out to sea? Are you saying you never see a clear delineation between sea and sky?

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Flat Earth Theory / Re: Curvature of the Horizon

« on: March 16, 2023, 11:03:12 AM »

So if you see bumps of waves where is the exact line? At the peak or the trough of the waves? If so which ones? Some are bigger than others.

If we're getting to this level of detail, its a median line between the peaks and troughs.  The volume of water present above the median is equal to the volume absent below the line.  The position of the median is a function of gravity, the shape of the Earth, and the volume of water on the Earth.  Waves are principally a localised topical effect of wind; past, and present. 

@Gonzo; by my count that's 3 individuals who have failed to respond to your question.  Its difficult to respond to someone's opinion on a phenomenon (in this case the maritime horizon), when we don't know whether they are actually in a position to observe it directly.  (Or, indeed, if they've ever observed it directly).

Quite.

It’s rather a habit of some people.

I haven’t posted recently as I’m on holiday in the Isle of Skye, Scotland, I’m staying in a cottage literally a few metres from the sea. On clear days I can see a very obvious clear delineation between sea and sky.

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Flat Earth Theory / Re: Curvature of the Horizon

« on: March 07, 2023, 08:14:05 PM »

Yes, often times, the sea and sky are indistinguishable.  The other half of that equation is that often times the difference is like night and day. 

If you haven't observed this yourself, perhaps you need to get out more.

Whether or not I 'need to get out more," is not the point. You, nor anyone else for that matter, have zero ability to determine the precise conditions of any object from three miles away. Especially with the naked eye.

That's the point.

We weren’t talking about how far away the horizon was. We were saying that it was often very clear. Because it is. I can count on the fingers of one hand how many times a year I used to struggle to see a clear horizon in good visibility.

You couldn't plot with any accuracy the exact line of the horizon from 3 miles away. Even if you did manage to wade thogh the swell, waves, freak waves, refraction, haze, reflections.

And on a clear day, with little swell or chop, lo and behold it’s still a clear line.

I really don’t understand how people can say it’s not. I spent the first 18 years of my life looking at the horizon out to sea literally hundreds of times every day.

Do you live near the coast, SimonC?

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Flat Earth Theory / Re: Curvature of the Horizon

« on: March 07, 2023, 06:16:44 AM »

Yes, often times, the sea and sky are indistinguishable.  The other half of that equation is that often times the difference is like night and day. 

If you haven't observed this yourself, perhaps you need to get out more.

Whether or not I 'need to get out more," is not the point. You, nor anyone else for that matter, have zero ability to determine the precise conditions of any object from three miles away. Especially with the naked eye.

That's the point.

We weren’t talking about how far away the horizon was. We were saying that it was often very clear. Because it is. I can count on the fingers of one hand how many times a year I used to struggle to see a clear horizon in good visibility.

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Flat Earth Theory / Re: Curvature of the Horizon

« on: March 04, 2023, 07:12:22 PM »

Yes it is. It is very often a clear, definite line.

Do you live near the coast?

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Flat Earth Theory / Re: Curvature of the Horizon

« on: February 27, 2023, 08:51:45 PM »

I spent the first 18 years of my life in Plymouth, UK, and would often see exactly that type of image with my own eyes through my binoculars. Especially Royal Navy vessels, and those of other nations, manoeuvering for Flag Officer Sea Training exercises just offshore. Anyone used to living by the coast and ship-watching would recognise that picture. I can take similar pictures of the Eddystone lighthouse too, approximately 12 miles offshore from Plymouth. It has stump next to it, the remnants of the previous lighthouse (Smeaton's Tower) that now stands on the promanade on Plymouth Hoe, and depending on one's height above sea level, the stump is either visible or not. It's a great test.

Seeing a 'crisp' or 'sharp', or whatever other words anyone wants to use, horizon is not unusual from such a location.