[SimonC]

In the above scenario there is nothing that could prove the earth is a ball. Very strange and futile question.

Very good observation Simon.  It's not supposed to.

The question is actually quite simple.  Most flat earthers should be able to answer it without any problem.  You claim the earth is flat because you don't see any curvature, right?  The question is, what would you expect to see on this large Earth such that you would say "Hey, now I'm convinced teh Earth is a sphere!"

The thing is, even if the Earth was a sphere 12,742,000 meters in diameter, you still could not see a curvature.  Given that, why do you think the Earth is flat?  What is it you are seeing that you should not see on a spherical Earth 12,742,000 meters in diameter?  If you are confused about the whole meters thing, use 41,804,460 feet.  Would you expect to see a curve standing, or boating, on a sphere 41,804,460 feet in diameter?

I have already answered your question and stated there is nothing in that scenario that could prove the earth is a ball.
Why not let us know what would convince YOU that the world was a sphere by sitting in a boat in the middle of an ocean with no land in sight?

Limited to just sitting in a boat in the middle of the ocean, things we can observe are clearly limited. However:

- the existence of a clear, distinct horizon line on days with good visibility means the earth cannot be flat. If the earth was flat, the only occasion where you would see a distinct line like that would be when you were close to the 'edge' itself. If the earth was flat, and you were a long way from the edge, then there would be no clear horizon - you would instead get what we see on poorer visibility days, where there is a blurry, indistinct horizon, caused by particulate matter in the atmosphere limiting how far you can see.

- if you lie in the boat at night, and watch the stars, you will notice that they appear to rotate in a circular manner around a fixed point at a rate of one rotation per day. The fact that they behave in this way, but are clearly 'decoupled' from the sun and moon, gives a strong indication that the surface we are on is rotating somehow, and that the stars are a lot further away from us than the sun and moon. If you add in the fact that that the elevation above the horizon of the centre of the point of rotation (roughly where the north star is, in the northern hemisphere) is directly related to your latitude, then we can start to make deductions about the likely shape of the earth.

Not to mention that if you're out in the middle of the ocean and wish to navigate to a desired land location, you bust out your sextant and start observing. Then using your declination and sightings, making sure there are no collimation errors, log the sighting time, then using the Hilaire method, calculate via triangulation including the sphericity of earth and derive your position relative to your map. And on your way you go.

What exactly is it that you 'start observing'...presumably with your sextant?

[stack]

In the above scenario there is nothing that could prove the earth is a ball. Very strange and futile question.

Very good observation Simon.  It's not supposed to.

The question is actually quite simple.  Most flat earthers should be able to answer it without any problem.  You claim the earth is flat because you don't see any curvature, right?  The question is, what would you expect to see on this large Earth such that you would say "Hey, now I'm convinced teh Earth is a sphere!"

The thing is, even if the Earth was a sphere 12,742,000 meters in diameter, you still could not see a curvature.  Given that, why do you think the Earth is flat?  What is it you are seeing that you should not see on a spherical Earth 12,742,000 meters in diameter?  If you are confused about the whole meters thing, use 41,804,460 feet.  Would you expect to see a curve standing, or boating, on a sphere 41,804,460 feet in diameter?

I have already answered your question and stated there is nothing in that scenario that could prove the earth is a ball.
Why not let us know what would convince YOU that the world was a sphere by sitting in a boat in the middle of an ocean with no land in sight?

Limited to just sitting in a boat in the middle of the ocean, things we can observe are clearly limited. However:

- the existence of a clear, distinct horizon line on days with good visibility means the earth cannot be flat. If the earth was flat, the only occasion where you would see a distinct line like that would be when you were close to the 'edge' itself. If the earth was flat, and you were a long way from the edge, then there would be no clear horizon - you would instead get what we see on poorer visibility days, where there is a blurry, indistinct horizon, caused by particulate matter in the atmosphere limiting how far you can see.

- if you lie in the boat at night, and watch the stars, you will notice that they appear to rotate in a circular manner around a fixed point at a rate of one rotation per day. The fact that they behave in this way, but are clearly 'decoupled' from the sun and moon, gives a strong indication that the surface we are on is rotating somehow, and that the stars are a lot further away from us than the sun and moon. If you add in the fact that that the elevation above the horizon of the centre of the point of rotation (roughly where the north star is, in the northern hemisphere) is directly related to your latitude, then we can start to make deductions about the likely shape of the earth.

Not to mention that if you're out in the middle of the ocean and wish to navigate to a desired land location, you bust out your sextant and start observing. Then using your declination and sightings, making sure there are no collimation errors, log the sighting time, then using the Hilaire method, calculate via triangulation including the sphericity of earth and derive your position relative to your map. And on your way you go.

What exactly is it that you 'start observing'...presumably with your sextant?

Look up how to use a sextant. There's endless documentation as to how sextant sightings and subsequent navigations are performed. And it's not 'my' sextant, sextants have been around for 250+ years.

[BillO]

Why not let us know what would convince YOU that the world was a sphere by sitting in a boat in the middle of an ocean with no land in sight?

Well, your answer does not answer the question I asked, but I'll answer you.  I maintain you could never determine the shape of the earth (one way or the other) by such an observation.  The Earth is just too big for that.  So not seeing a curvature by looking out over the sea would convince me of nothing because that is exactly what I expect to see on either a mostly flat Earth or one that is a sphere of 41,804,460 feet in diameter.

However, that is all flat earthers have.  That you don't see any curvature.  The point is, you cannot expect to see any curvature whether the Earth is flat or not because if it is spherical it is just too big to be able to see a curvature

Given that and that you seem to agree with me, why do you think the Earth is flat?

[DuncanDoenitz]

So the distinct line you see is the beginning, the top, or the falling away of the curve? Do you not consider that if the earth was a continuous curve there would be no distinct line? Curves dont have distinct lines. Even curves 'fade away'. And if there was a distinct line it would be a different (further or nearer line) for every person of differing heights and stood on different heights above sea level. You cant have an infinite number of 'distinct lines'.

Of course curves have a distinct line.  Look at a snooker/pool ball; it curves away to the "horizon", which is a distinct line.  Sit in your car and look over the hood.  Distinct line. 

And of course there are an infinite number of distinct lines, that's the point.  The visible horizon is unique to the observer.  If I am standing 1 metre behind you on a boat, your horizon is one metre further away than mine. 

[AATW]

So the distinct line you see is the beginning, the top, or the falling away of the curve? Do you not consider that if the earth was a continuous curve there would be no distinct line? Curves dont have distinct lines. Even curves 'fade away'.

What are you talking about? "Curves don't have distinct lines" is a meaningless sentence. And in what sense do curves "fade away"?
Look at any spherical object. You can see the edge of it, can't you? A clear line. The edge isn't all fuzzy. I happen to have a globe in the house so I took this photo:



Is that a clear enough line for you? And if you zoom in to a portion of this image then even at this scale the horizon starts to flatten out:



That's what the horizon is. Why would that happen on a FE? What presents you seeing further than the distinct horizon on a FE? It isn't visibility, you can see distant landmasses beyond the horizon, you just can't see the bottom of them. The only exception to that is on a foggy day when visibility is poor, in that case you don't see a clear horizon line, the sea just fades out. But what would cause the clear horizon line on a FE? What is hiding the rest of the sea?

And if there was a distinct line it would be a different (further or nearer line) for every person of differing heights and stood on different heights above sea level.

Correct. Which is exactly what we observe. The higher you ascend the further you can see. You ever looked out a airplane window? You can see a horizon much further away than when you're on the beach. I took these photos with the same globe as above, raising the camera to simulate going up in altitude.



Note how the label "Russia" can be clearly seen in the bottom of the 3 photos but is hidden behind the curve in the top photo from a "lower" altitude.
Note out the word "Mountains" (upside down) is further from the horizon as you ascend.

You cant have an infinite number of 'distinct lines'.

The distinct line isn't a physical thing, it's simply the limit of how far you can see on the globe earth, and the reason for it is the earth curves away from you. That's why the distance to the horizon increases with altitude, because you can see further over the curve. This diagram illustrates the principle:

[SteelyBob]

So the distinct line you see is the beginning, the top, or the falling away of the curve? Do you not consider that if the earth was a continuous curve there would be no distinct line? Curves dont have distinct lines. Even curves 'fade away'. And if there was a distinct line it would be a different (further or nearer line) for every person of differing heights and stood on different heights above sea level. You cant have an infinite number of 'distinct lines'.

As the others have said, the line you see is merely the tangent of your sight line and the globe. Yes, that does mean that the horizon appears in a different place for different observer heights. If the distance to the horizon is less than the meteorological visibility, then you will see a distinct horizon line. If it’s not, then you won’t see one - it will be blurry or completely indistinct, which is what you would see every day on a flat earth. The fact that you don’t see this should be a major clue that the earth isn’t flat.

And moving on to your second point if you know of such a person who lay in a boat staring towards the sky at every single star for 24 non-stop hours and mentally noting their continuous shift in positions exactly then I should like to meet this person. And you say that this gives an indication that the surface we are on is rotating - had you not given any consideration to the fact that it could be the stars that are rotating and not the earth?

Well, you don’t need to do this - simple photography lets you do it very clearly, or you can just note the azimuth and elevation of a few obvious stars and see the pattern. Either way, they rotate in a neat circular pattern, every 24 hours.

So then you might reasonably ask ‘couldn’t the stars be moving around the earth?’ - a perfectly valid line of enquiry. But there are several ways we know this is not the case:

- if the stars are rotating around the earth, why does the neutral point at the centre of rotation vary linearly with our latitude, and why do the stars disappear below the horizon during part of the their rotation? If I’m in Scotland and you’re in Africa, why can I see stars that are below the horizon for you? The wiki invoked ‘bendy light’ at this point. Aside from being an incomplete explanation, if it were the case that light was bending in the vertical plane, as asserted, then the neat circular pattern that we observe would not happen, as the paths would be distorted by the EA.

- why the exact 24 hour period of rotation, precisely the same as the apparent periodicity of the sun, when the sun is clearly ‘moving’ in a different manner and at a closer range than the stars?

A rotating spherical earth explains all of these things perfectly. We can even measure the rotation using gyroscopes, both mechanical and laser. It all lines up.

[Action80]

In the above scenario there is nothing that could prove the earth is a ball. Very strange and futile question.

Very good observation Simon.  It's not supposed to.

The question is actually quite simple.  Most flat earthers should be able to answer it without any problem.  You claim the earth is flat because you don't see any curvature, right?  The question is, what would you expect to see on this large Earth such that you would say "Hey, now I'm convinced teh Earth is a sphere!"

The thing is, even if the Earth was a sphere 12,742,000 meters in diameter, you still could not see a curvature.  Given that, why do you think the Earth is flat?  What is it you are seeing that you should not see on a spherical Earth 12,742,000 meters in diameter?  If you are confused about the whole meters thing, use 41,804,460 feet.  Would you expect to see a curve standing, or boating, on a sphere 41,804,460 feet in diameter?

I have already answered your question and stated there is nothing in that scenario that could prove the earth is a ball.
Why not let us know what would convince YOU that the world was a sphere by sitting in a boat in the middle of an ocean with no land in sight?

Limited to just sitting in a boat in the middle of the ocean, things we can observe are clearly limited. However:

- the existence of a clear, distinct horizon line on days with good visibility means the earth cannot be flat. If the earth was flat, the only occasion where you would see a distinct line like that would be when you were close to the 'edge' itself. If the earth was flat, and you were a long way from the edge, then there would be no clear horizon - you would instead get what we see on poorer visibility days, where there is a blurry, indistinct horizon, caused by particulate matter in the atmosphere limiting how far you can see.

Explain the thought process leading to this momentous conclusion!

Is this only on the water? Is the water perfectly flat?

I mean, jesus...your pronouncement here comes across as is if it is uttered on Mt. Sinai!

You are making a claim about the only possible conclusive state of a particular set of circumstances that would exist in a world you absolutely, vehemently deny is possible.

Pardon me, but I call bs. You deny something exists, but presume to have a clue about what it could possibly be like.

- if you lie in the boat at night, and watch the stars, you will notice that they appear to rotate in a circular manner around a fixed point at a rate of one rotation per day. The fact that they behave in this way, but are clearly 'decoupled' from the sun and moon, gives a strong indication that the surface we are on is rotating somehow, and that the stars are a lot further away from us than the sun and moon. If you add in the fact that that the elevation above the horizon of the centre of the point of rotation (roughly where the north star is, in the northern hemisphere) is directly related to your latitude, then we can start to make deductions about the likely shape of the earth.

Again, with the grand pronouncements of rotation. The crap above us moving, not the other way around. And yeah, the sun, moon, and stars, all occupy different levels of the firmament. the decouple is the only thing you got right.

[AATW]

Explain the thought process leading to this momentous conclusion!

OK.
The distance to the horizon, from an average height standing on the sea shore, is less than 3 miles.
As you look out to sea you can observe about 3 miles of sea then there's a sharp line, on a clear day, and above that line you can see the sky.

Why can't you see any more sea? If the earth is flat then what's stopping you? It isn't visibility. We know that because if there are distant land-masses or ships which are further than the horizon then you can see them, you just can't see the top of them.
On a globe this makes sense, the earth curves away from you. That's why you can't see any more sea. It's why you can't see the bottom of distant ships of land-masses, they're hidden by the earth's curve. And it's why the distance to the horizon increases with increasing altitude, that allows you to see further over the curve:



But the bottom of those two diagrams shows the FE claim, that the sea is flat. If that's so then why is there a horizon? The person has a clear line of sight to the rest of the sea, why can't they see it? What causes a sharp horizon line on a FE?

Is this only on the water? Is the water perfectly flat?

Water is the clearest way to see this as it's unusual for 3 or more miles of land to be flat. And by flat I mean "following the contour of the earth". The sea is flat in as much as while there are waves and swells, on a calm day these are relatively small. The sea doesn't have hills and valleys. But the sea does follow the contour of the earth, and the horizon observations I mentioned above are evidence of that.

You deny something exists, but presume to have a clue about what it could possibly be like.

Well, it's more that we know the something doesn't exist because observations of the horizon indicate that it can't.
We know that on a beach we can only see about 3 miles of sea. The only reasons I can think of why we wouldn't be able to see more are:
a) Visibility prevents you seeing further
b) The rest of the sea is occluded by something.

We know that option A isn't true - you can see part of objects further than the horizon. That leaves option B.  So what's occluding the rest of the sea on a FE? On a RE it's the curve of the earth itself, what's your explanation? Unless there's another reason I haven't considered?

Note that on a foggy day when visibility IS less than the distance to the horizon then you don't see a sharp horizon line



That's what I'd expect to see were the earth flat. At some point visibility would stop you seeing more sea, but that wouldn't be a clear sharp line, more of a fading out as gradually you can see things less clearly. If you have an explanation for a sharp horizon line on a FE then feel free to present it.

[SteelyBob]

Explain the thought process leading to this momentous conclusion!

I did explain it.

Is this only on the water? Is the water perfectly flat?

Well, the original question proposed a boat in the middle of the ocean. Is the water perfectly flat...that would help, or we need the boat to be substantially bigger than the waves, otherwise we'd just be looking at waves, and not the horizon several miles away. I don't think that's particularly contentious, regardless of your views on the earth's shape, is it?

I mean, jesus...your pronouncement here comes across as is if it is uttered on Mt. Sinai!

Note really sure where you're going with this one.

You are making a claim about the only possible conclusive state of a particular set of circumstances that would exist in a world you absolutely, vehemently deny is possible.

Conclusive...no, but we can exclude the possibility that the world is flat from the simple existence of a clear horizon. If the visibility is, say 20km, and world is 10s of thousands of km across, then there cannot be a clear horizon all around us if the world is flat. And yet there is, so the earth cannot be flat.

Pardon me, but I call bs. You deny something exists, but presume to have a clue about what it could possibly be like.

Again, not really clear what you're on about here. Shout BS if you like, but you would help your argument if you actually engaged with the science, instead of just decrying what I'm saying.

Again, with the grand pronouncements of rotation. The crap above us moving, not the other way around. And yeah, the sun, moon, and stars, all occupy different levels of the firmament. the decouple is the only thing you got right.

Again, if the 'crap around us' is moving, and the earth is flat, why does stuff disappear below the horizon during its circular journey? Why can I see something in Scotland that is below the horizon for you in Africa? Why is the centre of rotation different in the northern hemisphere to the southern one? Why can you only see one of the two centres of rotation at any one time, why not both? Surely if the earth was flat, and things were rotating above us, there would be only one centre of rotation?

[Pete Svarrior]

What causes a sharp horizon line on a FE?

I contest your assertion that the horizon would be "sharp" in either model. In fact, you already submitted your own photographs of how blurry a sphere's "horizon" really is.

In essence, you gave us these images of a poorly-defined edge that gradually fades away while bluntly asserting that they are in fact well-defined and sharp:



This is problematic, because:

• Your assertion contradicts the photographic evidence you produced. [If your assertion is true, then your photographs are "wrong"]
• This is despite a flaw in your experiment which should skew it in your favour - you were able to entirely ignore atmospheric effects due to your experiment's small scale. These would make the real horizon even blurrier.
• Your assertion directly contradicts the RE model. [If your assertion is true, then RE is an impossibility]

In short, you have now joined the echelons of RE'ers who, in their desperation to defend their favourite model at all costs, gallop away from the orthodoxy and start making RE up on the spot. Although I completely support your personal exploration of the Earth's shape*, I think you need a more structured approach. Nonetheless, this is the closest you've come to Zeteticism, and that effort ought to be noted. The next step would be not presupposing your outcome - if you follow a similar approach, but without declaring that it must support your favourite shape, you'll start making some real progress.

* - I know this sentence may come across as sarcastic. I promise it isn't.

[Action80]

Explain the thought process leading to this momentous conclusion!

I did explain it.

Thinking you did and actually doing it are two different things.

Is this only on the water? Is the water perfectly flat?

Well, the original question proposed a boat in the middle of the ocean. Is the water perfectly flat...that would help, or we need the boat to be substantially bigger than the waves, otherwise we'd just be looking at waves, and not the horizon several miles away. I don't think that's particularly contentious, regardless of your views on the earth's shape, is it?

That you do not understand the water actually needs to be perfectly flat to meet the criteria of your claim, not mine, is a huge clue your claim is totally bogus.

I mean, jesus...your pronouncement here comes across as if it is uttered on Mt. Sinai!

Note really sure where you're going with this one.

See below.

You are making a claim about the only possible conclusive state of a particular set of circumstances that would exist in a world you absolutely, vehemently deny is possible.

Conclusive...no, but we can exclude the possibility that the world is flat from the simple existence of a clear horizon. If the visibility is, say 20km, and world is 10s of thousands of km across, then there cannot be a clear horizon all around us if the world is flat. And yet there is, so the earth cannot be flat.

Repeating the claim you originally made does not help you here. Kindly explain how or why someone should believe you when you try to tell others that a sharp horizon would be absolutely impossible on the very real flat earth plane when you absolutely reject the concept to begin with. You are telling me for instance, there could not possibly be any pictures of a sharp horizon taken, for instance in Kansas...totally ridiculous. The rest of the conditions you wish to interject here are just more smoke, having been caught with the matches already. No one should trust you or any other RE'er to be objective on the physical nature of the flat earth plane. All of you need to twist words and jump through multiple hoops on a consistent basis. You cannot possibly relate the nature of the true picture of what you deny.

Pardon me, but I call bs. You deny something exists, but presume to have a clue about what it could possibly be like.

Again, not really clear what you're on about here. Shout BS if you like, but you would help your argument if you actually engaged with the science, instead of just decrying what I'm saying.

I am on science. You are not.

Again, with the grand pronouncements of rotation. The crap above us moving, not the other way around. And yeah, the sun, moon, and stars, all occupy different levels of the firmament. the decouple is the only thing you got right.

Again, if the 'crap around us' is moving, and the earth is flat, why does stuff disappear below the horizon during its circular journey? Why can I see something in Scotland that is below the horizon for you in Africa? Why is the centre of rotation different in the northern hemisphere to the southern one? Why can you only see one of the two centres of rotation at any one time, why not both? Surely if the earth was flat, and things were rotating above us, there would be only one centre of rotation?

Everything above us, even planes if it were possible to view them to the full extent, would merge into the horizon. The human eye can only see so far.

[Action80]

Explain the thought process leading to this momentous conclusion!

OK.
The distance to the horizon, from an average height standing on the sea shore, is less than 3 miles.
As you look out to sea you can observe about 3 miles of sea then there's a sharp line, on a clear day, and above that line you can see the sky.

Why can't you see any more sea? If the earth is flat then what's stopping you? It isn't visibility. We know that because if there are distant land-masses or ships which are further than the horizon then you can see them, you just can't see the top of them.
On a globe this makes sense, the earth curves away from you. That's why you can't see any more sea. It's why you can't see the bottom of distant ships of land-masses, they're hidden by the earth's curve. And it's why the distance to the horizon increases with increasing altitude, that allows you to see further over the curve:



But the bottom of those two diagrams shows the FE claim, that the sea is flat. If that's so then why is there a horizon? The person has a clear line of sight to the rest of the sea, why can't they see it? What causes a sharp horizon line on a FE?

All of your explanation assumes facts, such as consistency of atmoplanar conditions are consistent through the entirety of the viewing area.

Impossible, especially over water.

Is this only on the water? Is the water perfectly flat?

Water is the clearest way to see this as it's unusual for 3 or more miles of land to be flat. And by flat I mean "following the contour of the earth". The sea is flat in as much as while there are waves and swells, on a calm day these are relatively small. The sea doesn't have hills and valleys. But the sea does follow the contour of the earth, and the horizon observations I mentioned above are evidence of that.

You deny something exists, but presume to have a clue about what it could possibly be like.

Well, it's more that we know the something doesn't exist because observations of the horizon indicate that it can't.
We know that on a beach we can only see about 3 miles of sea. The only reasons I can think of why we wouldn't be able to see more are:
a) Visibility prevents you seeing further
b) The rest of the sea is occluded by something.

We know that option A isn't true - you can see part of objects further than the horizon. That leaves option B.  So what's occluding the rest of the sea on a FE? On a RE it's the curve of the earth itself, what's your explanation? Unless there's another reason I haven't considered?

Note that on a foggy day when visibility IS less than the distance to the horizon then you don't see a sharp horizon line



That's what I'd expect to see were the earth flat. At some point visibility would stop you seeing more sea, but that wouldn't be a clear sharp line, more of a fading out as gradually you can see things less clearly. If you have an explanation for a sharp horizon line on a FE then feel free to present it.

Again, no one needs to pay attention to the expectations of an RE'er concerning what a flat earth would look like. You deny it so vehemently one can rest assured you have spent ZERO TIME in conjecture regarding its appearance.

Me on the other hand look out and know that's what I am looking at every day of my life.

[SteelyBob]

In essence, you gave us these images of a poorly-defined edge that gradually fades away while bluntly asserting that they are in fact well-defined and sharp:

I think that has rather more to do with the fact that his camera is clearly focussing at a point nearer than the horizon than it does with the shape of the earth. If we were to take a similar shot with the focus at the 'horizon' it would be a lot crisper.

Aside from that, what do you think causes a visible horizon? If the edge of the earth is many thousands of miles away, what exactly are we looking at when we see the horizon?

[SteelyBob]

That you do not understand the water actually needs to be perfectly flat to meet the criteria of your claim, not mine, is a huge clue your claim is totally bogus.

No, not perfectly flat - as AATW explains, it just needs to be calm enough that the waves don't block your sightline to the horizon. That might be because it's very calm indeed and you are low down, or because there is some swell but you are high up in a large vessel. Either way, you'll see the horizon, met visibility permitting.

Repeating the claim you originally made does not help you here. Kindly explain how or why someone should believe you when you try to tell others that a sharp horizon would be absolutely impossible on the very real flat earth plane when you absolutely reject the concept to begin with.

That's a very back-to-front way of approaching this. I reject the concept of a flat earth because the evidence does not support it, not the other way around. There's lots of reasons for that - we are focussing on one small part of the evidence here. We are simply asking ourselves what we would see if we out at sea in a boat, and the earth was flat. The fact we can see a horizon on clear days is hugely important - it tells us something. Do you have a mechanism for explaining the existence of a horizon in FE?

You are telling me for instance, there could not possibly be any pictures of a sharp horizon taken, for instance in Kansas...totally ridiculous.

No, that's not what I'm saying at all. You get a good clear horizon in all sorts of places with extensive flat land...the original thought piece was about the sea, so that's where we went. The sea is useful because it eliminates complications like hills and valleys etc, but if you were talking about salt flats, or somewhere like that with many miles of flat terrain, the argument would be the same - why do you get a horizon if the earth is flat? Why can't you see beyond a few miles?

The rest of the conditions you wish to interject here are just more smoke, having been caught with the matches already. No one should trust you or any other RE'er to be objective on the physical nature of the flat earth plane. All of you need to twist words and jump through multiple hoops on a consistent basis. You cannot possibly the true picture of what you deny.

That's just ad hom garbage.

Everything above us, even planes if it were possible to view them to the full extent, would merge into the horizon. The human eye can only see so far.

Here is your major misunderstanding. The human eye isn't limited by distance. You can see big things far away, and small things up close. Your eyes ability to see things is an angular resolution problem - distance is only half the equation. Consider the stars - we discussed how they rotate in circles earlier. If they are dropping to the horizon because of their distance from you, why are they moving around in a circle? They can't be any further or closer at the top or bottom, or they would be moving in elliptical path. Is it not more likely that they are moving in a circle, but something...the horizon...is obscuring your view of them for part of that circular journey? The same thing is true for large things on earth - we can often see large objects beyond the horizon, partially obscured by it - large boats, distant hills, tall buildings etc...so the horizon can't be an eyesight / distance thing - we can see beyond it.

[Pete Svarrior]

If we were to take a similar shot with the focus at the 'horizon' it would be a lot crisper.

Yes, he could have taken better photos. It would be difficult, and he'd have to actively work around many inconveniences, but it's possible. That's why I included my comment about the crucial flaw of scale - the bypasses you suggest wouldn't work in the Earth's case.

Aside from that, what do you think causes a visible horizon? If the edge of the earth is many thousands of miles away, what exactly are we looking at when we see the horizon?

Please familiarise yourself with basic FET before attempting to debate it.

[SteelyBob]

Please familiarise yourself with basic FET before attempting to debate it.

Well aware of the various ideas espoused in the wiki. I’m just asking what you personally believe to be the case.

[Action80]

The human eye isn't limited by distance. You can see big things far away, and small things up close.

^ Here

Your eyes ability to see things is an angular resolution problem - distance is only half the equation. 

All in one post...

Amazing!!!

[SteelyBob]

The human eye isn't limited by distance. You can see big things far away, and small things up close.

^ Here

Your eyes ability to see things is an angular resolution problem - distance is only half the equation. 

All in one post...

Amazing!!!

Which part of that don’t you understand?

[AATW]

I contest your assertion that the horizon would be "sharp" in either model. In fact, you already submitted your own photographs of how blurry a sphere's "horizon" really is.

Sigh...
Tbh, when I posted the pictures I did notice they weren't that well focussed. I think my stupid phone focused on the foreground.
I just hoped no-one would notice, I should have known better...

And OK, in real life you're right, there are atmospheric effects and waves which mean it might not be 100% sharp. But the point is according to the RE model you're looking at the edge of something. And the edges of somethings are generally pretty well defined. I mean, I can see houses out the window. I can see where the rooves ends and beyond that I just see the sky, a roof doesn't just fade gradually into the sky. The sea is, famously, not solid, but a body of liquid on a calm day has a flat enough surface to approximate a solid. I would urge you not to be pedantic about the word "flat" here, I'm talking on a scale of a few miles square where any curvature is negligible.

There's no issue with visibility on a clear day. You can see distant landmarks beyond the horizon. I think you're being a bit pedantic about the word sharp. OK, the horizon might not be 100% sharp but can we agree that there's a pretty obvious difference between these two images:





In the first it's a clear day, you can see a fairly clear, sharp horizon line. In the second it's a foggy day, the visibility is less than the distance to the horizon and the result is there is no sharp horizon line, it's more of a fading out. The latter is what I would imagine one would see on a FE. My reasoning being that on a RE it makes sense that as the sea curves away from you, you're not able to see any more sea, that's why you get the well defined boundary between sea and sky. Some other explanation is required on a FE. I'll repost this diagram:



In the bottom image I've drawn an arbitrary horizon to match the one at the top RE diagram. But what is stopping you seeing further? If you're looking out on, say, the Atlantic, there's thousands more miles of sea, why can you only see the first few miles? This does all presuppose light travels in roughly straight lines of course (and yes, I know refraction is a thing, but that generally allows one to see further than expected). You may invoke EA I guess, but there has to be some explanation. A RE model quite neatly explains why you only see a few miles out to sea before observing a clear horizon line, and it explains why that horizon distance increases with altitude as does the angle dip to the horizon.

Nonetheless, this is the closest you've come to Zeteticism, and that effort ought to be noted. The next step would be not presupposing your outcome - if you follow a similar approach, but without declaring that it must support your favourite shape, you'll start making some real progress.

I'd suggest the method of starting with a hypothesis and devising an experiment to test it has served humanity pretty well. You may disagree, but most of our advances in technology and engineering over the past couple of centuries have been based on us having good working models of reality. The thing I don't understand about Zeteticism is on your Wiki it says:

For example, in questioning the shape of the Earth the zetetic does not make a hypothesis suggesting that the Earth is round or flat and then proceed to testing that hypothesis; he skips that step and devises an experiment that will determine the shape of the Earth, and bases his conclusion on the result of that experiment.

Well ok...but what's the experiment? Let's say we make an observation of the horizon without presupposing the shape of the earth. OK, so what's the conclusion?
It could be that the earth curves away from us, that would explain that observation.
It could be that the sea actually just ends after a few miles.
It could be that the earth is flat but some effect like EA bends the light and that prevents us seeing further.
Any of these interpretations are possible, so how does that experiment help us?

You might fairly reasonably say that's not the right experiement, in which case what is? Any experiment has some underlying assumptions and could be interpreted multiple ways.

[AATW]

All of your explanation assumes facts, such as consistency of atmoplanar conditions are consistent through the entirety of the viewing area.

Any conclusion has to be built on certain underlying assumptions. My assumptions are that visibility on a clear day is greater than the distance to the horizon - I believe that can be easily justified, as I've said you can see distant landmarks beyond the horizon. And I've assumed light travels in roughly straight lines, refraction is a thing and does affect results somewhat, but it doesn't allow you to see indefinitely.

Me on the other hand look out and know that's what I am looking at every day of my life.

OK. So what observations have you made and what conclusions have you drawn.
Why do you believe there is a clear horizon line on a FE when you look out to sea (on a clear day)