[Tom Bishop]

But in any case, your "experiment" simply demonstrates the part I already wrote in bold above. The very thin hull in your picture will become hard to resolve at a certain distance. And yes, in that case optical magnification could "restore" it. But the reason it can be "restored" is that it isn't hidden in the first place. It isn't behind anything, it just becomes difficult to discern at a certain distance.

Which is exactly what Rowbotham is describing in Earth Not a Globe. When bodies are smaller than 1/60th of a degree they become lost to optical resolution, and are beyond perception. So, you were wrong. This effect does exist and it is reversible with optical zoom.

[secretagent10]

This effect does exist and it is reversible with optical zoom.

Telescopes on earth can resolve images a tiny fraction of the ship’s apparent size.
There are plenty of amateur images resolving Jupiter’s bands swirling, even its moons. This is extraordinarily smaller than making out a ship. With Jupiter, there is no geometric obstacle while with a ship there clearly is. That geometric obstacle would be the curvature of the earth. No amount of optical zoom will reverse a geometric obstruction.

[WTF_Seriously]

But in any case, your "experiment" simply demonstrates the part I already wrote in bold above. The very thin hull in your picture will become hard to resolve at a certain distance. And yes, in that case optical magnification could "restore" it. But the reason it can be "restored" is that it isn't hidden in the first place. It isn't behind anything, it just becomes difficult to discern at a certain distance.

Which is exactly what Rowbotham is describing in Earth Not a Globe. When bodies are smaller than 1/60th of a degree they become lost to optical resolution, and are beyond perception. So, you were wrong. This effect does exist and it is reversible with optical zoom.

It's not a matter of whether it exists, it's a matter of whether or not it explains what we see with objects going beyond the horizon.  You know, that zetetic observation thingy.
 As has been clearly illustrated, Rowbotham's effect in no way illustrates what we actually observe.  No amount of optical zoom can bring back the hidden parts of the objects.

[AATW]

But in any case, your "experiment" simply demonstrates the part I already wrote in bold above. The very thin hull in your picture will become hard to resolve at a certain distance. And yes, in that case optical magnification could "restore" it. But the reason it can be "restored" is that it isn't hidden in the first place. It isn't behind anything, it just becomes difficult to discern at a certain distance.

Which is exactly what Rowbotham is describing in Earth Not a Globe. When bodies are smaller than 1/60th of a degree they become lost to optical resolution, and are beyond perception. So, you were wrong. This effect does exist and it is reversible with optical zoom.

So Rowbotham's hot take is that as you get further away from things they get smaller and then at some point you can no longer see them?
I mean...yeah, but that's not some breakthrough discovery. What was I wrong about? I said:

1) Ships, buildings and other distant landmarks disappear behind the horizon and do so increasingly with distance. They cannot be "restored" with optical resolution as Rowbotham claimed

Note the word "behind". If an object is partially behind the horizon you can zoom in as much as you like, you're not going to restore the missing part. In my previous post I showed an image demonstrating that. But I went on to say, and this is the part you keep ignoring, even after I bolded it in my previous post:

I mean, they can if they're this side of the horizon, but not once they're beyond it.

So yeah, if things are NOT behind the horizon, but are so far away that they are just an indistinct dot then yes, optical zoom will "restore" them.
But as I have demonstrated with my experiment - which is basically the same as the one on your Wiki - that cannot explain the sinking ship effect.
That's where Rowbotham was wrong. Because even if the thin "hull" is at the top it still becomes impossible to see at a certain distance and can be "restored" with optical zoom. Nothing to do with sinking.

TL;DR - the limits of optical resolution do not explain the sinking ship effect. Rowbotham was wrong about that.
And you know that's true, you have a whole other Wiki page which tries to explain the sinking ship effect using other mechanisms like swells or refraction. As I've noted, that second one is strange as refraction generally means you can see more of an object than you would be able to on a globe with no atmosphere.

And I like Tumeni's argument a lot. It's a better one than mine. If you're at a high vantage point looking out to sea and looking down at a lower vessel then your line of sight from you to the top of the vessel must continue downwards to intersect the sea IF the sea is flat. It has to, that's just basic geometry. So that photo is impossible on a FE. I'd suggest a sharp horizon line is impossible on a FE. Why is there a distinct distance at which you can't see the sea any more, what stops you seeing further? It can't be visibility, on a foggy day you can't see the horizon but the sea just fades out, there's no distinct line.

Now, you can invoke EA to explain this I guess, but in doing so you are admitting that the observation is not one would expect on a FE and you have to hypothesise a mechanism to explain that. And that's your fundamental problem. You simultaneously claim the earth is flat because of observations, and then have to invoke mechanisms to explain why observations don't match a FE. So which is it?

[Tron]

As a quick aside, Globers believe refraction generally makes objects rise and Levelers believe refraction makes objects sink?  MCToon used this as his main argument about why refraction cannot explain things on a flat Earth.

There is no consensous here?  Is there an experiment we can do?

[Tumeni]

Which is exactly what Rowbotham is describing in Earth Not a Globe. When bodies are smaller than 1/60th of a degree they become lost to optical resolution, and are beyond perception. So, you were wrong. This effect does exist and it is reversible with optical zoom.

Rowbottom describes his flags at Bedford Level;



He indicates an upward sightline to the higher flag, and a level sightline across the tops of those of equal height. I've added the black flag, which is lower than those around it, and lower than the observer's eye level. The sightline to this must be a downward one. Upward to the higher flag, level to the others, downward to the black one.

Any instance of the observer above the object, looking out at the object on the water, given sufficient water, MUST have the observer seeing water behind and beyond the top of the object. If he sees clear sky, with water below the top of the object in his field of view, the water cannot be flat. 

So, with sufficient water, and no landfall beyond, the downward sightline from observer to lower object/flag MUST meet the water. It cannot miss it. Parallel lines never meet, non-parallel must meet.

 

[Tumeni]

I like Tumeni's argument a lot. It's a better one than mine. If you're at a high vantage point looking out to sea and looking down at a lower vessel then your line of sight from you to the top of the vessel must continue downwards to intersect the sea IF the sea is flat. It has to, that's just basic geometry. So that photo is impossible on a FE.

Thank You.

Here's another, taken from YouTube channel 'Flatsa'. You can see my original critique comments in the video below reflecting the same argument that I present here.



Observer height was 210m, and there are four objects/elements in play here; from left to right, there's the lighthouse on the Isle of May - 73m optical height; there's the ship on or near the horizon; height unknown, distance unknown, but we can certainly state it to be less than 210m in height, and in the video we see it pass in front of the third element, the Inch Cape Met Mast (you might need to watch the video below to see it). The large hill to the right is Berwick Law, on the mainland, but with a peak of 187m, still lower than the observation point. There's plenty of water beyond all of them. No landfall until Norway, some 700km+ away.

So, all of the sightlines from 210m down to the 73m lighthouse, the far smaller ship, the met mast, and Berwick Law, should meet the water. But they do not. We can work out the geometry of it all, and from that, we find that the sightline through the top of the lighthouse, for instance, should meet the water between the observation point and the met mast, IF the water is flat. But it does not. If it did, the met mast would be above the lighthouse in the observer's field of view.  All we see behind and beyond the lighthouse is clear sky. And the topmost point of the lighthouse is above the topmost point of the met mast. The seas CANNOT be flat.

This diagram shows the principle that applies to this observation, and to that of the Jumbo Kinetic that I posted earlier;





----------------------------------------------------------------




 

[Tom Bishop]

So yeah, if things are NOT behind the horizon, but are so far away that they are just an indistinct dot then yes, optical zoom will "restore" them.
But as I have demonstrated with my experiment - which is basically the same as the one on your Wiki - that cannot explain the sinking ship effect.
That's where Rowbotham was wrong. Because even if the thin "hull" is at the top it still becomes impossible to see at a certain distance and can be "restored" with optical zoom. Nothing to do with sinking.

Rowbotham was not wrong. You were just lazy and didn't bother to read the book. He also studied the cases where the hull could not be restored with a telescope. He said that in the cases where the hull could not be restored it was clearly due to a special cause, due to inconsistency, inaccuracy, or weather correlation of such observations.

https://wiki.tfes.org/Sinking_Ship_Effect

Inconsistency

It has been found that the Sinking Ship effect is inconsistent. At times it occurs and at other times it does not occur.

In The Plane Truth: The History of the Flat Earth Movement by Robert Schadewald we find:

  “ Let Richard A. Proctor, science writer, astronomer, and good-humored arch-enemy of Parallax, describe another experiment:

' Mr. Rowbotham did a very bold thing … at Plymouth. He undertook to prove, by observations made with a telescope upon the Eddystone Lighthouse from the Hoe and from the beach, that the surface of the water is flat. From the beach, usually only the lantern can be seen. From the Hoe, the whole of the lighthouse is visible under favourable conditions. Duly on the morning appointed, Mr. Rowbotham appeared. From the Hoe a telescope was directed towards the lighthouse, which was well seen, the morning being calm and still and tolerably clear. On descending to the beach it was found that, instead of the whole lantern being visible as usual, only half could be seen—a circumstance doubtless due to the fact that the Air’s refractive power, which usually diminishes the dip due to the earth’s curvature by about one-sixth part, was less efficient that morning than usual. The effect of the peculiarity was manifestly unfavourable to Mr. Rowbotham’s theory. The curvature of the earth produced a greater difference than usual between the appearance of a distant object as seen from a certain low station (though still the difference fell short of that of which would be shown if there were no error). But Parallax claimed the peculiarity observable that morning as an argument in favour of his flat earth. It is manifest, he said, “that there is something wrong about the accepted theory; for it tells us that some much less of the lighthouse should be seen from the beach than from the Hoe, whereas still less was seen.” And many of the Plymouth folk went away from the Hoe that morning, and from the second lecture, in which Parallax triumphantly quoted the results of the observation, with the feeling which had been expressed seven years before in the Leicester Advertiser, that "some of the most important conclusions of modern astronomy had been seriously invalidated." [ref. 1.20] ' ”

From p.223 in Earth Not a Globe we read:

  “ It is well known that even on lakes of small dimensions and also on canals, when high winds prevail for some time in the same direction, the ordinary ripple is converted into comparatively large waves. On the "Bedford Canal," during the windy season, the water is raised into undulations so high, that through a powerful telescope at an elevation of 8 inches, a boat two or three miles away will be invisible; but at other times, through the same telescope the same kind of boat may be seen at a distance of six or eight miles.

During very fine weather when the water has been calm for some days and become as it were settled down, persons are often able to see with the naked eye from Dover the coast of France, and a steamer has been traced all the way across the channel. At other times when the winds are very high, and a heavy swell prevails, the coast is invisible, and the steamers cannot be traced the whole distance from the same altitude, even with a good telescope.

Instances could be greatly multiplied, but already more evidence has been given than the subject really requires, to prove that when a telescope does not restore the hull of a distant vessel it is owing to a purely special and local cause. ”

On p.217 we read additional accounts of inconsistency:

  “ In May, 1864, the author, with several gentlemen who had attended his lectures at Gosport, made a number of observations on the "Nab" light-ship, from the landing stairs of the Victoria Pier, at Portsmouth. From an elevation of thirty-two inches above the water, when it was very calm, the greater part of the hull of the light vessel was, through a good telescope, plainly visible. But on other occasions, when the water was much disturbed, no portion of the hull could be seen from the same elevation, and with the same or even a more powerful telescope. At other times, when the water was more or less calm, only a small portion of the hull, and sometimes the upper part of the bulwarks only, could be seen. These observations not only prove that the distance at which objects at sea can be seen by a powerful telescope depends greatly on the state of the water, but they furnish a strong argument against rotundity. The "Nab" light-ship is eight statute miles from the Victoria pier, and allowing thirty-two inches for the altitude of the observers, and ten feet for the height of the bulwarks above the water line, we find that even if the water were perfectly smooth and stationary, the top of the hull should at all times be fourteen feet below the horizon. Many observations similar to the above have been made on the north-west light-ship, in Liverpool Bay and on light-vessels in various parts of the sea round; Great Britain and Ireland.

It is a well known fact that the light of Eddystone lighthouse is often plainly visible from the beach in Plymouth Sound, and sometimes, when the sea is very calm, persons sitting in ordinary rowing boats can see the light distinctly from that part of the Sound which will allow the line of sight to pass between "Drake's Island" and the. western end of the Breakwater. The distance is fourteen statute miles. In the tables published by the Admiralty, and also by calculation according to the supposed rotundity of the earth, the light is stated to be visible thirteen nautical or over fifteen statute miles, yet often at the same distance, and in rough weather, not only is the light not visible but in the day time the top of the vane which surmounts the lantern, and which is nearly twenty feet higher than the centre of the reflectors or the focus of the light, is out of sight.

A remarkable instance of this is given in the Western Daily Mercury, of October 25th, 1864. After lectures by the author at the Plymouth Athenæum and the Devonport Mechanics' Institute, a committee was formed for the purpose of making experiments on this subject, and on the general question of the earth's form. A report and the names of the committee were published in the Journal above referred to; from which the following extract is made.

"OBSERVATION 6TH.--On the beach, at five feet from the water level, the Eddystone was entirely out of sight."
At any time when the sea is calm and the weather clear, the light of the Eddystone may be seen from an elevation of five feet above the water level; and according to the Admiralty directions, it "maybe seen thirteen nautical (or fifteen statute), miles," 1 or one mile further away than the position of the observers on the above-named occasion; yet, on that occasion, and at a distance of only fourteen statute miles, notwithstanding that it was a very fine autumn day, and a clear background existed, not only was the lantern, which is 80 feet high, not visible, but the top of the vane, which is 100 feet above the foundation, was, as stated in the report "entirely out of sight." There was, however, a considerable "swell" in the sea beyond the breakwater.

That vessels, lighthouses, light-ships, buoys, signals, and other known and fixed objects are sometimes more distinctly seen than at other times, and are often, from the same common elevation, entirely out of sight when the sea is rough, cannot be denied or doubted by any one of experience in nautical matters. ”

[markjo]

Rowbotham was not wrong. You were just lazy and didn't bother to read the book. He also studied the cases where the hull could not be restored with a telescope. He said that in the cases where the hull could not be restored it was clearly due to a special cause, due to inconsistency, inaccuracy, or weather correlation of such observations.

Thank you for explaining exactly why such observations should not be used as evidence of anything.

[AATW]

He also studied the cases where the hull could not be restored with a telescope. He said that in the cases where the hull could not be restored it was clearly due to a special cause, due to inconsistency, inaccuracy, or weather correlation of such observations.

OK, so he's doing the same thing you are.
Simultaneously claiming that hulls can be restored and they don't really sink behind the horizon...and then in cases when that isn't true, invoking other mechanisms to try and explain it. As I said, this is your problem. You simultaneously claim that observations better match a FE, and then invoke mechanisms to explain why they don't.
I note you haven't commented on Tumeni's point. If you're at a high vantage point and looking down at the top of a lower vessel then your line of sight has to continue on and intersect the sea. It has to, if the earth is flat. Why can you see the sky behind the top of the ship in that picture and not the sea? Why is there a horizon at all on a FE? It isn't visibility as you can see distant ships and land beyond the horizon, you just can't see all of them because they are hidden behind the horizon. You can hypothesise mechanisms to explain that, but in doing so you are acknowledging that observations do not match a FE.

[Tumeni]

I note you haven't commented on Tumeni's point. If you're at a high vantage point and looking down at the top of a lower vessel then your line of sight has to continue on and intersect the sea. It has to, if the earth is flat. Why can you see the sky behind the top of the ship in that picture and not the sea? Why is there a horizon at all on a FE? It isn't visibility as you can see distant ships ....

Exactly. There are four ships/boats in the photo with the Jumbo Kinetic (that plus three others).

To the left, a container ship and some kind of fishing vessel beyond it. The JK to the right of centre, and, pretty much in the centre, a ship or boat on or near the horizon.

The original full-frame shot;



The area where the fourth craft is (along with the smaller craft beyond the container ship), both highlighted in red;



And a crop showing the fourth craft;




Again; I, the observer, was at 100m above sea level. The manufacturer's data sheet for the JK states it is 52m air draft (height above the waterline), so 52m above sea level. It is roughly half the height that I was observing from. There's no landfall beyond the JK until Norway, some 700km or so beyond, so why do I see clear sky beyond the tops of the cranes, if my sightline should lead directly to the water if the seas are flat?

It's simple geometry of right-angle triangles. Drop a vertical from the observation point, continue the presumed flat plane of the sea to meet that vertical below the observer, and we have a right-angle. Join observer to top of ship with a straight line, a descending hypotenuse, and that line MUST, if continued beyond the top of the ship, meet the sea, as described and illustrated above.

It's not lack of visibility. We can see wave crests beyond the JK, all the way to the horizon, and to the fourth ship on or near it. We can see way beyond the JK.

[WTF_Seriously]

Now, you can invoke EA to explain this I guess,

Didn't want to copy your whole post.  Recap, you could invoke EA as to why a ship's hull appears to go behind the horizon.

Over my morning coffee, I happened to think about the Bishop's experiment for some reason.  https://wiki.tfes.org/Experimental_Evidence  That led me to thinking about this thread and your statement.

Assuming that everything in the WIKI is truthful and accurate,  the Bishop experiment would empirically verify that EA bends light less than 20 inches at the water's surface over some 23 miles.  That being the case, EA would bend light significantly less than that at the distance of roughly 3 miles that a ship begins to sink below the horizon.  This leads to the fact, should empirical evidence be believed, the majority of the 20+ feet of cargo ship hull should be visible at distances in excess of 23 miles to sea.

[SimonC]

How come an image such as this one has never been seen (the top image in the below link) ? i.e. a boat cruising along parallel to the coastline just beyond the horizon. If anyone saw this they would think it was sinking and call the coastguard. This one has to be a fake so how come there are no real ones? Or are there?

https://www.google.com/imgres?imgurl=https%3A%2F%2Fqph.cf2.quoracdn.net%2Fmain-qimg-a04c6df7269268394ce2348d6476bf22.webp&imgrefurl=https%3A%2F%2Fwww.quora.com%2FCan-anyone-shatter-the-argument-Ships-disappear-over-the-horizon-because-of-the-limits-of-human-vision-not-a-spherical-world-I-found-it-online&tbnid=RP1SeUCdRJsTgM&vet=12ahUKEwiFncKpk-v7AhXVhHMKHdEkAKAQMygAegQIARBZ..i&docid=J20kGyaxtSGR5M&w=602&h=337&q=why%20is%20there%20no%20sea%20beyond%20a%20ship%20on%20the%20horizon&ved=2ahUKEwiFncKpk-v7AhXVhHMKHdEkAKAQMygAegQIARBZ

[stack]

How come an image such as this one has never been seen (the top image in the below link) ?

What makes you say it "has never been seen"? And why does it have to be fake? How do you know that no one called the coast guard?

Seeing this would probably prompt to call the coast guard, not the other one...

[WTF_Seriously]

How come an image such as this one has never been seen (the top image in the below link) ? i.e. a boat cruising along parallel to the coastline just beyond the horizon. If anyone saw this they would think it was sinking and call the coastguard.

WTF......Seriously.

The majority of the people in the world would simply say, "Oh, look at that ship beyond the horizon."
It's an everyday occurrence.  Why would it warrant a call to the coastguard?

[Tumeni]

How come an image such as this one has never been seen (the top image in the below link) ? i.e. a boat cruising along parallel to the coastline just beyond the horizon.

What makes you think this has "never been seen"? How many people have you asked? Have you asked ANYONE if they have seen this? Or is your "never" just based on your own, limited, experience?

[SimonC]

How come an image such as this one has never been seen (the top image in the below link) ?

What makes you say it "has never been seen"? And why does it have to be fake? How do you know that no one called the coast guard?

Seeing this would probably prompt to call the coast guard, not the other one...

If you have some thatearent processed/photoshopped I would like to see them but I have never seen an authentic one of a boat sailing parallel to the shore with its bottom half seemingly below the water level.

[SimonC]

How come an image such as this one has never been seen (the top image in the below link) ? i.e. a boat cruising along parallel to the coastline just beyond the horizon. If anyone saw this they would think it was sinking and call the coastguard.

WTF......Seriously.

The majority of the people in the world would simply say, "Oh, look at that ship beyond the horizon."
It's an everyday occurrence.  Why would it warrant a call to the coastguard?

How do you know what they would say? do you have any authentic pics of the same occurrence?

[SimonC]

How come an image such as this one has never been seen (the top image in the below link) ? i.e. a boat cruising along parallel to the coastline just beyond the horizon.

What makes you think this has "never been seen"? How many people have you asked? Have you asked ANYONE if they have seen this? Or is your "never" just based on your own, limited, experience?

it would aid the round earth theorists if it was a regular occurrence but for some reason i think not.

[Tumeni]

How come an image such as this one has never been seen (the top image in the below link) ? i.e. a boat cruising along parallel to the coastline just beyond the horizon.

What makes you think this has "never been seen"? How many people have you asked? Have you asked ANYONE if they have seen this? Or is your "never" just based on your own, limited, experience?

it would aid the round earth theorists if it was a regular occurrence but for some reason i think not.

Why would you "think" that, without some meaningful statistics to back it up?