The Flat Earth Society
Flat Earth Discussion Boards => Flat Earth Investigations => Topic started by: edby on January 01, 2019, 06:38:41 PM
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Rowbotham says (http://www.sacred-texts.com/earth/za/za14.htm)
The distance across St. George's Channel, between Holyhead and Kingstown Harbour, near Dublin, is at least 60 statute miles. It is not an uncommon thing for passengers to notice, when in, and for a considerable distance beyond the centre of the Channel, the Light on Holyhead Pier, and the Poolbeg Light in Dublin Bay, as shown in fig. 23.
And he explains
The Lighthouse on Holyhead Pier shows a red light at an elevation of 44 feet above high water; and the Poolbeg Lighthouse exhibits two bright lights at an altitude of 68 feet; so that a vessel in the middle of the Channel would be 30 miles from each light; and allowing the observer to be on deck, and 24 feet above the water, the horizon on a globe would be 6 miles away. Deducting 6 miles from 30, the distance from the horizon to Holyhead, on the one hand, and to Dublin Bay on the other, would be 24 miles. The square of 24, multiplied by 8 inches, shows a declination of 384 feet. The altitude of the lights in Poolbeg Lighthouse is 68 feet; and of the red light on Holyhead Pier, 44 feet. Hence, if the earth were a globe, the former would always be 316 feet and the latter 340 feet below the horizon, as seen in the following diagram, fig. 24. The line of sight H, S, would be a tangent touching the horizon at H, and passing more than 300 feet over the top of each lighthouse.
Many instances could be given of lights being visible at sea for distances which would be utterly impossible upon a globular surface of 25,000 miles in circumference. (etc)
Taking the second part first. The curve calculator (https://www.metabunk.org/curve) agrees that the horizon would be 6 miles distant, and the calculation for the hidden amount given 30 miles with the observer 24 feet above water is 384 feet. So science agrees with Rowbotham on what science says.
However his first claim is that ‘it is not an uncommon thing’ (giving no source) for observers to see the harbour lights at both directions, which is impossible according to science. So is the earth really flat then?
However, this source (http://200proofsthatericdubayisaliar.blogspot.com/2018/06/93-holyhead-pier-light-and-poolbeg.html) disagrees, noting the publication ‘Sailing directions for the coast of Ireland. Part I (https://archive.org/details/sailingdirectio01deptgoog)’, 1877, compiled by Staff Commander Richard Hoskin of the Royal Navy from various Admiralty surveys.
Poolbeg Light. - A white tower on the east end of the south wall at the entrance of the river Liffey, exhibits one fixed white light at an elevation of 68 feet above high water, visible 12 miles.
My emphasis. Of course it is theoretically possible that the Admiralty document, published as a guide to help navigators safely move from harbour to harbour, was deliberately designed to lure sailors to their death, but why would it do that? It is also theoretically possible that Rowbotham was making the whole thing up. Who can say?
A simple investigation could resolve the matter.
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If one source says that a lighthouse is visible when 30 miles away, why isn't it possible for another source to say that a light house is visible when at 12 miles away?
That source does not even specify that 12 miles is the limit, only that it was seen. And, even if it did, which I cannot find specified, there is such a thing as marine fog and atmospheric conditions that can regularly obscure.
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If one source says that a lighthouse is visible when 30 miles away, why isn't it possible for another source to say that a light house is visible when at 12 miles away?
That source does not even specify that 12 miles is the limit, only that it was seen. And, even if it did, which I cannot find specified, there is such a thing as marine fog and atmospheric conditions that can regularly obscure.
My understanding is that visible range refers to maximum visible range (otherwise there would be no point in publishing it).
Note also this:
When first sighting a light, an observer can determine if it is on the horizon by immediately reducing his height of eye. If the light disappears and then reappears when the observer returns to his original height, the light is on the horizon. This process is called bobbing a light.
Why would changing the observer's height cause the light to appear and disappear?
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You might also look up the concept of 'geographic range', which is a navigational concept, meaning precisely the maximum range a light is visible.
If you can also 'bob the light', it means you are at geographic range.
Here is a neat video. Warning: the instructor assumes 'as we all know', that the earth is round. But this is only 'the practical experience of nautical men', as Rowbotham says.
https://www.youtube.com/watch?v=lO-oUm4f84E
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If one source says that a lighthouse is visible when 30 miles away, why isn't it possible for another source to say that a light house is visible when at 12 miles away?
That source does not even specify that 12 miles is the limit, only that it was seen. And, even if it did, which I cannot find specified, there is such a thing as marine fog and atmospheric conditions that can regularly obscure.
My understanding is that visible range refers to maximum visible range (otherwise there would be no point in publishing it).
Note also this:
When first sighting a light, an observer can determine if it is on the horizon by immediately reducing his height of eye. If the light disappears and then reappears when the observer returns to his original height, the light is on the horizon. This process is called bobbing a light.
Why would changing the observer's height cause the light to appear and disappear?
It just says visible, not visible range.
Regardless, 30 miles is pretty far away. When looking out on the ocean it is not uncommon for the marine layer to build up.
Rowbotham doesn't say that the lighthouse is always visible, only that it and others like it have been seen at those ranges and that people were speculating about refraction to explain it.
The 12 mile source seems ambiguous in exactly what it's talking about or how it was determined, but if it did imply range, it would not be surprising if a book listed a shorter distance for it's visible range, rather than publishing a range that some people have seen it from. The purpose would be to give information to sailors on what they could expect to see.
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It just says visible, not visible range.
Regardless, 30 miles is pretty far away. When looking out on the ocean it is not uncommon for the marine layer to build up.
Rowbotham doesn't say that the lighthouse is always visible, only that it and others like it have been seen at those ranges and that people were speculating about refraction to explain it.
It would not be surprising if a book listed a shorter distance for it's visible range, rather than publishing a range that some people have seen it from. The purpose would be to give information to sailors on what they could expect to see.
I recommend you watch the instructional video above. These things are not written down just for fun.
You might also be interested in the range table at t = 219.
https://youtu.be/lO-oUm4f84E?t=219
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It just says visible, not visible range.
Regardless, 30 miles is pretty far away. When looking out on the ocean it is not uncommon for the marine layer to build up.
Rowbotham doesn't say that the lighthouse is always visible, only that it and others like it have been seen at those ranges and that people were speculating about refraction to explain it.
It would not be surprising if a book listed a shorter distance for it's visible range, rather than publishing a range that some people have seen it from. The purpose would be to give information to sailors on what they could expect to see.
I recommend you watch the instructional video above. These things are not written down just for fun.
You might also be interested in the range table at t = 219.
https://youtu.be/lO-oUm4f84E?t=219 (https://youtu.be/lO-oUm4f84E?t=219)
I took a brief look at the video. It appears that he is just encouraging the use of the theoretical Round Earth model on paper to determine a range, rather than testing it in real life.
How do we know that this wasn't the same method used in the source you quoted for the shorter range? What you posted seems more discrediting to the shorter range argument, if that is the method used.
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I took a brief look at the video. It appears that he is just encouraging the use of the theoretical Round Earth model on paper to determine a range
That's right. I assume, as a marine instructor, he knows what he is talking about.
In fact, applying that table to Rowbotham's example, I get 6.7 statute miles for the visible range of the boat at 24 feet height, plus 11.3 miles for the 68 feet of the lighthouse, giving a total maximum distance of 18 miles.
So Rowbotham's figure of 30 statute miles is way off. I wonder if he was just making this up? Do have evidence he was telling the truth?
rather than testing it in real life.
He is teaching people who will 'test it in real life' in circumstances that will hopefully save their life!
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Northeastern Maritime Institute (https://northeastmaritime.com/).
I suggest he is using textbooks which teach heuristics (rules of thumb) which have long passed the test of time by 'practical seafaring men'.
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I took a brief look at the video. It appears that he is just encouraging the use of the theoretical Round Earth model on paper to determine a range
That's right. I assume, as a marine instructor, he knows what he is talking about.
In fact, applying that table to Rowbotham's example, I get 6.7 statute miles for the visible range of the boat at 24 feet height, plus 11.3 miles for the 68 feet of the lighthouse, giving a total maximum distance of 18 miles.
So Rowbotham's figure of 30 statute miles is way off. I wonder if he was just making this up? Do have evidence he was telling the truth?
Rowbotham and Co. took their information from credible sources of the day. Dubey writes about the matter:
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A copy of the book “The Lighthouses of the World” and a calculator are enough to prove that the Earth is not a globe, but an extended flat plane. The distance from which various lighthouse lights around the world are visible at sea far exceeds what could be found on a globe Earth 25,000 miles in circumference. For example, the Dunkerque Light in southern France at an altitude of 194 feet is visible from 28 miles away. Spherical trigonometry dictates that if the Earth was a globe with the given curvature of 8 inches per mile squared, this light should be hidden 190 feet below the horizon!
The Port Nicholson Light in New Zealand is 420 feet above sea-level and visible from 35 miles away which means it should be 220 feet below the horizon. The Egerö Light in Norway is 154 feet above high-water and visible from 28 statute miles where it should be 230 feet below the horizon. The Light at Madras, on the Esplanade, is 132 feet high and visible from 28 miles away, where it should be 250 feet below the line of sight. The Cordonan Light on the west coast of France is 207 feet high and visible from 31 miles away, putting it 280 feet below the line of sight. The light at Cape Bonavista, Newfoundland is 150 feet above sea-level and visible at 35 miles, where it should be 491 feet below the horizon. And the lighthouse steeple of St. Botolph’s Parish Church in Boston is 290 feet tall and visible from over 40 miles away, where it should be hidden a full 800 feet below the horizon!
“The distance across St. George's Channel, between Holyhead and Kingstown Harbour, near Dublin, is at least 60 statute miles. It is not an uncommon thing for passengers to notice, when in, and for a considerable distance beyond the centre of the Channel, the Light on Holyhead Pier, and the Poolbeg Light in Dublin Bay. The Lighthouse on Holyhead Pier shows a red light at an elevation of 44 feet above high water; and the Poolbeg Lighthouse exhibits two bright lights at an altitude of 68 feet; so that a vessel in the middle of the Channel would be 30 miles from each light; and allowing the observer to be on deck, and 24 feet above the water, the horizon on a globe would be 6 miles away. Deducting 6 miles from 30, the distance from the horizon to Holyhead, on the one hand, and to Dublin Bay on the other, would be 24 miles. The square of 24, multiplied by 8 inches, shows a declination of 384 feet. The altitude of the lights in Poolbeg Lighthouse is 68 feet; and of the red light on Holyhead Pier, 44 feet. Hence, if the earth were a globe, the former would always be 316 feet and the latter 340 feet below the horizon!”'—Zetetic Astronomy, Earth Not a Globe!” (59)
“The lights which are exhibited in lighthouses are seen by navigators at distances at which, according to the scale of the supposed ‘curvature’ given by astronomers, they ought to be many hundreds of feet, in some cases, down below the line of sight! For instance: the light at Cape Hatteras is seen at such a distance (40 miles) that, according to theory, it ought to be nine-hundred feet higher above the level of the sea than it absolutely is, in order to be visible! This is a conclusive proof that there is no ‘curvature,’ on the surface of the sea - ‘the level of the sea,’- ridiculous though it is to be under the necessity of proving it at all: but it is, nevertheless, a conclusive proof that the Earth is not a globe.”—William Carpenter, “100 Proofs the Earth is Not a Globe” (5)
The Isle of Wight lighthouse in England is 180 feet high and can be seen up to 42 miles away, a distance at which modern astronomers say the light should fall 996 feet below line of sight. The Cape L’Agulhas lighthouse in South Africa is 33 feet high, 238 feet above sea level, and can be seen for over 50 miles. If the world was a globe, this light would fall 1,400 feet below an observer’s line of sight! The Statue of Liberty in New York stands 326 feet above sea level and on a clear day can be seen as far as 60 miles away. If the Earth was a globe, that would put Lady Liberty at an impossible 2,074 feet below the horizon! The lighthouse at Port Said, Egypt, at an elevation of only 60 feet has been seen an astonishing 58 miles away, where, according to modern astronomy it should be 2,182 feet below the line of sight!
"The distance at which lights can be seen at sea entirely disposes of the idea that we are living on a huge ball.” —Thomas Winship, “Zetetic Cosmogeny” (58)
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He is teaching people who will 'test it in real life' in circumstances that will hopefully save their life!
If so, then as marine layer visibility can vary, better to assume short than long.
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Rowbotham and Co. took their information from credible sources of the day. Dubey writes about the matter:
This http://200proofsthatericdubayisaliar.blogspot.com/2018/06/dubays-lighthouse-proofs-shown-to-be.html argues that Dubay's arguments are bogus.
Dubay took his sources from Rowbotham and Carpenter. Where is the independent credible evidence?
Please supply the 'credible sources for the day' that you are claiming.
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Neither Dubey, Rowbotham, Winship, or Carpenter wrote the Lighthouses of the World book.
These are not their claims at all. Look up what quotes and citations are. These are the claims of academia and the traditional sciences.
From your link: "In the two Sailing Direction documents that I have access to online there is NOT A SINGLE ACCOUNT of a lighthouse or light that is visible from further than it should be on a spherical Earth."
Considering your video on how some of these ranges are determined, apparently by a theoretical Round Earth model on paper, we know why that may be the case. Your video appears to discredit this source.
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Now this is very interesting. Findlay’s 1861 book is here (https://books.google.co.uk/books?redir_esc=y&id=XlkBAAAAQAAJ&q=visible+in+miles#v=onepage&q=visible%20in%20miles&f=false).
We can look up the claims above in this book, where Findlay gives both the height of the lighthouse and the figure ‘visible in miles’, which he gives as the minimum distance to which the light can be seen, in clear weather, from a height of 10 feet above sea level. Note he adds that ‘they could be seen at any distance with increased elevation’.
I checked out some of these using the curve calculator (https://www.metabunk.org/curve/). Put in first the height of the lighthouse to give its distance to the horizon, then add the distance to the horizon of 10 feet.
It turns out (1) for the figures I looked at, Rowbotham adds about 5 miles to the ‘visible distance’, plus (2) he also cherry picks for the distances where Findlay’s estimate is inconsistent with his other estimates. For example, Rowbotham says “The Light at Madras, on the Esplanade, is 132 feet high and visible from 28 miles away”. But the figure Findlay gives is 24 miles, not 28! The curve calculator gives around 18 miles. However, on the same page Findlay says the lighthouse at Pondicherry is 131 feet, only a foot less than Madras, with a visible distance of 15 miles, which is less than expected.
So is someone making these numbers up?
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Firstly, I believe the author you are quoting for those is Dubey, not Rowbotham. Rowbotham's quote is separated with quotes, with an emdash which says that it is from ENAG.
Secondly, 28 statute miles = 24.33 nautical miles (https://www.google.com/search?num=30&client=firefox-b-1&ei=_O4rXMGcE4yItQXlzKzIDg&q=28+statute+miles+in+nautical+miles&oq=28+statute+miles+in+nautical+miles&gs_l=psy-ab.3...57488.77078..77325...5.0..0.206.4351.0j36j1......0....1..gws-wiz.......0i71j33i10j33i10i299.mMRoz7oT8JQ). To defend Dubey, you are likely looking at conversions.
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Interesting information from Bob Schadewald’s book regarding Rowbotham’s lighthouse theories and how they may not be as accurate as claimed:
"A substantial section of Earth Not a Globe is devoted to lighthouses that can be seen at greater distances than should be allowed by the earth’s rotundity. Rowbotham drew most of his examples from Lighthouses of the World by Alexander Findlay, and Bresher examined this work closely. He wrote:
“Parallax” gives about twenty cases of this kind, collected from a book, “Lighthouses of the World,” which contains a list of upwards of 2000 lighthouses, and then says (page 173,) “Many other cases could be given from the same work, shewing that the practical observations of mariners, engineers, and surveyors, entirely ignore the doctrine that the earth is a globe.” [ref. 1.79]
Bresher called this a bold but unwarranted assertion. He had himself examined Findlay’s book and found therein entries for about 2000 lighthouses. As far as he could tell, Rowbotham had found and listed almost every one that seemed to be visible at too great a distance. But there was more:
Now while “Parallax” was attentively scanning the “Lighthouses of the World,” to find out some that could be seen farther than they ought to be seen, on the supposition that the earth is a globe of about 25,000 miles in circumference; he could not but find many more which cannot be seen as far as they ought to be, on the above assumption. [ref. 1.80]
Somehow Rowbotham neglected to mention these. Bresher promised that “for every instance ‘Parallax’ can quote, where the distance given is greater than the theory requires, I will quote another where it is less.” [ref. 1.81] As a down payment he listed ten lighthouses that (from the information provided) couldn’t be seen far as they should. [ref. 1.82] Bresher suspected that misprints or local peculiarities accounted for many of the apparent discrepancies. Besides, Findlay wrote that the lights used were typically powerful enough to be seen for 60 miles or more, and refraction sometimes made lighthouses visible farther than they should be. In any case, Bresher argued that a few aberrant examples (about one percent) do not negate the earth’s sphericity.
In one case, Rowbotham used erroneous data published in a popular weekly, the Illustrated London News, which gave the wrong elevation for the light, when he could have found the correct figures in his favorite reference. [ref. 1.83] Reverend Bresher discussed this in detail and wrote:
The above, I am sorry to say, is but a fair specimen of the manner in which “Parallax” conducts his “search after truth;” and I do not think it will commend itself to any right-minded man. Anything he hears or reads, which can, by any means, be twisted into an argument against the Newtonian system, he seizes with avidity; not caring to ascertain its truth or untruth, even when he has the means of doing so, at hand. [ref. 1.84] "
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Somehow Rowbotham neglected to mention these. Bresher promised that “for every instance ‘Parallax’ can quote, where the distance given is greater than the theory requires, I will quote another where it is less.”
Come on, this is supposed to be meaningful? We can't see 30 miles into the horizon on every day and hour of the year.
A terrible argument, in my opinion. That person is clearly desperate for arguments and will say anything to try and deny whatever they want to deny. If the earth is a globe and if light travels in straight lines they should all be within globe distances, not some.
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Somehow Rowbotham neglected to mention these. Bresher promised that “for every instance ‘Parallax’ can quote, where the distance given is greater than the theory requires, I will quote another where it is less.”
Come on, this is supposed to be meaningful? We can't see 30 miles into the horizon on every day and hour of the year.
A terrible argument, in my opinion. That person is clearly desperate for arguments and will obviously say anything to try and deny whatever they want to deny. If the earth is a globe and if light travels in straight lines they should all be within globe distances, not some.
In ENAG, the basis of his calculations:
1) “...and allowing the observer to be on deck, and 24 feet above the water
2) "Allowing 16 feet for the altitude of the observer (which is more than is considered necessary, 2 10 feet being the standard; but 6 feet may be added for the height of the eye above the deck)”
It looks like he uses #2 for all of the ones he lists in ENAG below:
"The Egerö Light, on west point of Island, south coast of Norway, is fitted up with the first order of the dioptric lights, is visible 28 statute miles, and the altitude above high water is 154 feet. On making the proper calculation it will be found that this light ought to be sunk below the horizon 230 feet.
The Dunkerque Light, on the south coast of France, is 194 feet high, and is visible 28 statute miles. The ordinary calculation shows that it ought to be 190 feet below the horizon.
The Cordonan Light, on the River Gironde, west coast of France, is visible 31 statute miles, and its altitude is 207 feet, which would give its depression below the horizon as nearly 280 feet.
The Light at Madras, on the Esplanade, is 132 feet high, and is visible 28 statute miles, at which distance it ought to be beneath the horizon more than 250 feet.
The Port Nicholson Light, in New Zealand (erected in 1859), is visible 35 statute miles, the altitude being 420 feet above high water. If the water is convex it ought to be 220 feet below the horizon.
The Light on Cape Bonavista, Newfoundland, is 150 feet above high water, and is visible 35 statute miles. These figures will give, on calculating for the earth's rotundity, 491 feet as the distance it should be sunk below the sea horizon."
In “Lighthouses of the World”, Rowbotham’s reference, the following stats are listed:
Egerö Light
Height above High Water: 154’
Visible in Miles: 24 miles
Dunkerque Light:
Height above High Water: 194’
Visible in Miles: 24 miles
(Rowbotham has it at 28 miles)
Cordonan Light
(Couldn’t find)
Light at Madras
Height above High Water: 132’
Visible in Miles: 24 miles
(Rowbotham has it at 28 miles)
Port Nicholson Light
Height above High Water: 450'
Visible in Miles: 30 miles
(Rowbotham has it 420’ & 35 miles)
Cape Bonavista Light
Height above High Water: 150'
Visible in Miles: 30 miles
(Rowbotham has it at 35 miles)
I’m not sure why Rowbotham has different numbers than what’s in his source. I couldn't find a mention of nautical miles in the book so perhaps he assumed they were nautical and converted to statute.
Source:
(https://i.imgur.com/9Tkn4B6.jpg?2)
And we are talking about observing the light of a lighthouse, not just an observation of the lighthouse itself. Because there’s a distinct difference between observing a light source at distance versus, say just a structure/object.
Regarding Lighthouse lights:
"The luminous intensity of a light, or its candlepower, is expressed in international units called candelas. Intensities of lighthouse beams can vary from thousands to millions of candelas. The range at which a light can be seen depends upon atmospheric conditions and elevation. Since the geographic horizon is limited by the curvature of the Earth, it can be readily calculated for any elevation by standard geometric methods. In lighthouse work the observer is always assumed to be at a height of 15 feet, although on large ships he may be 40 feet above the sea. Assuming a light at a height of 100 feet, the range to an observer at 15 feet above the horizon will be about 16 nautical miles. This is known as the geographic range of the light. (One nautical mile, the distance on the Earth’s surface traversed by one minute of arc longitude or latitude, is equivalent to 1.15 statute miles or 1.85 kilometres.)
The luminous range of a light is the limiting range at which the light is visible under prevailing atmospheric conditions and disregarding limitations caused by its height and the Earth’s curvature. A very powerful light, low in position, can thus have a clear-weather luminous range greater than that when first seen by the mariner on the horizon. Powerful lights can usually be seen over the horizon because the light is scattered upward by particles of water vapour in the atmosphere; this phenomenon is known as the loom of the light.”
britannica.com/topic/lighthouse
This from the US Coast Guard’s Light List Volume I is the chart for distance to light source calculations which is different than Rowbotham's ENAG geometric observer to site calculations.
(https://i.imgur.com/9tUEGn9.png?1)
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See the chart below for some of the values given by Findlay, i.e. lighthouse height vs visibility in (statute) miles, against the theoretical GE values.
Note the majority of Findlay’s values are below the GE values, except for the four outliers which are the ones selected by Rowbotham.
Note also how closely the Findlay values follow the expected values. Why is this? Why is it difficult to find a Findlay lighthouse with a large height but low visibility, or with a low height but high visibilility? Why are short lighthouses never visible for a long distance?
Stepping right back, why did lighthouses exist at all in the days before satellites? Why go to the enormous expense of building them high at all?
(http://www.logicmuseum.com/w/images/c/cf/Lighthouse_visibility.jpg)
If the earth is a globe and if light travels in straight lines they should all be within globe distances, not some.
If all the data is correct, yes. But the chart above statistically suggests high margin of error in Findlay's data. What credible sources assure you that these are not just errors?
Note that I had to eliminate one obvious typo in Findlay's data. He clearly didn't check his published work too closely.
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The word "statute" appears nowhere in that nautical work. See the Google Books search feature. I will suggest that you two redo your analysis and graphs again and refrain from deception.
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This Samuel Rowbotham chap seems to have been quite a colourful character. Clearly someone of very individual mind who would probably regarded in a certain way if he were around today. Certainly if his thoughts and beliefs figure significantly in the way FET works today, much is explained by that alone.
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The word "statute" appears nowhere in that nautical work. See the Google Books search feature. I will suggest that you two redo your analysis and graphs again and refrain from deception.
I already have a conversion factor in the spreadsheet. However the phrase 'nautical' only appears twice, and not in the context of 'nautical miles'. It is possible the search facility is missing a misscanned item. Until then, I shall leave it at ordinary miles. The conversion does not make a significant difference in any case.
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The word "statute" appears nowhere in that nautical work. See the Google Books search feature. I will suggest that you two redo your analysis and graphs again and refrain from deception.
I agree, neither 'statute' nor 'nautical' miles appears in the book, at least in the scanned version we have. It's just odd that Rowbotham seemingly converted from what he assumed were nautical miles to statute. Nor did Rowbotham explain that he did so. Though it doesn't really make a difference as edby pointed out. And I assume Rowbotham listing one lighthouse as 420' instead of what his reference states is 450' is just a typo.
No one is deceiving here, just pointing out the data discrepancies.
But you're still not addressing the difference between visible light to observer distance as referenced by the US Coast Guard and Rowbotham's sole use of geographic object to observer distance.
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The word "statute" appears nowhere in that nautical work. See the Google Books search feature. I will suggest that you two redo your analysis and graphs again and refrain from deception.
I already have a conversion factor in the spreadsheet. However the phrase 'nautical' only appears twice, and not in the context of 'nautical miles'. It is possible the search facility is missing a misscanned item. Until then, I shall leave it at ordinary miles. The conversion does not make a significant difference in any case.
Except that when using nautical miles it goes against your theory.
Using statute miles, in a nautical work, to provide evidence for your theory is deceptive and you should have provided both versions rather than choosing to deceive through misrepresentation.
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Except that when using nautical miles it goes against your theory.
No it doesn't.
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Noticing that the non-UK data published by Findlay seemed less accurate than the UK (England and Scotland) data, I performed a correlation test between the theoretical visibility and the published visibility. Result
Correlation (UK data) 97.5%
Correlation (non-UK data) 24.1%
That indicates straight away that Findlay was using a different source for his non-UK data, almost certainly suspect (unless the earth really is flat outside of the UK).
As an example, consider the data from Spain.
Lighthouse: Country: Height: published: theoretical
Cape Mayor Spain 298 24 25.16
Cape Busto Spain 307 12 25.48
Corunna Spain 331 12 26.31
Cisargas Isles Spain 358 11 27.20
Bilbao Spain 380 10 27.91
San Sebastian Spain 431 15 29.47
Cape Prior Spain 448 15 29.97
Cape Finisterre Spain 468 20 30.54
Pasages Port Spain 486 14 31.05
Bayona Spain 595 20 33.94
You can see right away that the published data is inconsistent with itself. E.g. Cape Mayor (h 298, v 24) / Cape Busto (307, 12)
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The word "statute" appears nowhere in that nautical work. See the Google Books search feature. I will suggest that you two redo your analysis and graphs again and refrain from deception.
I already have a conversion factor in the spreadsheet. However the phrase 'nautical' only appears twice, and not in the context of 'nautical miles'. It is possible the search facility is missing a misscanned item. Until then, I shall leave it at ordinary miles. The conversion does not make a significant difference in any case.
Except that when using nautical miles it goes against your theory.
Using statute miles, in a nautical work, to provide evidence for your theory is deceptive and you should have provided both versions rather than choosing to deceive through misrepresentation.
I'm confused, are you saying Rowbotham was deceptive and deceiving through his misrepresentation? After all he used statute miles, taken from a nautical work, to provide evidence for his theory.
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The word "statute" appears nowhere in that nautical work. See the Google Books search feature. I will suggest that you two redo your analysis and graphs again and refrain from deception.
I already have a conversion factor in the spreadsheet. However the phrase 'nautical' only appears twice, and not in the context of 'nautical miles'. It is possible the search facility is missing a misscanned item. Until then, I shall leave it at ordinary miles. The conversion does not make a significant difference in any case.
Except that when using nautical miles it goes against your theory.
Using statute miles, in a nautical work, to provide evidence for your theory is deceptive and you should have provided both versions rather than choosing to deceive through misrepresentation.
I'm confused, are you saying Rowbotham was deceptive and deceiving through his misrepresentation? After all he used statute miles, taken from a nautical work, to provide evidence for his theory.
Rowbotham only has one example in that quote. You keep labeling Eric Dubey as Rowbotham.
Secondly, the distances are in nautical miles, and Dubey is converting to statute miles for his calculator.
Please point out where, in this nautical work, where statute miles are specified.
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The word "statute" appears nowhere in that nautical work. See the Google Books search feature. I will suggest that you two redo your analysis and graphs again and refrain from deception.
I already have a conversion factor in the spreadsheet. However the phrase 'nautical' only appears twice, and not in the context of 'nautical miles'. It is possible the search facility is missing a misscanned item. Until then, I shall leave it at ordinary miles. The conversion does not make a significant difference in any case.
Except that when using nautical miles it goes against your theory.
Using statute miles, in a nautical work, to provide evidence for your theory is deceptive and you should have provided both versions rather than choosing to deceive through misrepresentation.
I'm confused, are you saying Rowbotham was deceptive and deceiving through his misrepresentation? After all he used statute miles, taken from a nautical work, to provide evidence for his theory.
Rowbotham only has one example in that quote. You keep labeling Eric Dubey as Rowbotham.
Secondly, the distances are in nautical miles, and Dubey is converting to statute miles for his calculator.
Please point out where, in this nautical work, where statute miles are specified.
No, I already presented Rowbotham's data in a previous post. Has nothing to do with Dubey.
This is from ENAG, which I'm pretty sure Dubey didn't write:
"The Egerö Light, on west point of Island, south coast of Norway, is fitted up with the first order of the dioptric lights, is visible 28 statute miles, and the altitude above high water is 154 feet. On making the proper calculation it will be found that this light ought to be sunk below the horizon 230 feet.
The Dunkerque Light, on the south coast of France, is 194 feet high, and is visible 28 statute miles. The ordinary calculation shows that it ought to be 190 feet below the horizon.
The Cordonan Light, on the River Gironde, west coast of France, is visible 31 statute miles, and its altitude is 207 feet, which would give its depression below the horizon as nearly 280 feet.
The Light at Madras, on the Esplanade, is 132 feet high, and is visible 28 statute miles, at which distance it ought to be beneath the horizon more than 250 feet.
The Port Nicholson Light, in New Zealand (erected in 1859), is visible 35 statute miles, the altitude being 420 feet above high water. If the water is convex it ought to be 220 feet below the horizon.
The Light on Cape Bonavista, Newfoundland, is 150 feet above high water, and is visible 35 statute miles. These figures will give, on calculating for the earth's rotundity, 491 feet as the distance it should be sunk below the sea horizon."
If his source is using nautical miles, which is the assumption, Rowbotham converted them to statute miles (for some reason) in ENAG and didn't specify that he was doing so. How is that not deceptive, yet edby's is?
You still haven't addressed the question of Rowbotham's sole use of geographic observation versus light range observation. There is a difference.
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Those weren't the quotes that I provided. However, it looks like Rowbotham is also using statute miles in those. Probably because the 8 inches per mile square rule applies to statute miles.
In ENAG Rowbotham does specify that he is converting to statute miles around those quotes and that nautical miles were likely intended.
From just above what you quoted we read:
Many instances could be given of lights being visible at sea for distances which would be utterly impossible upon a globular surface of 25,000 miles in circumference. The following are examples:--
"The coal fire (which was once used) on the Spurn Point Lighthouse, at the mouth of the Humber, which was constructed on a good principle for burning, has been seen 30 miles off." 1
Allowing 16 feet for the altitude of the observer (which is more than is considered necessary, 2 10 feet being the standard; but 6 feet may be added for the height of the eye above the deck), 5 miles must be taken from the 30 miles, as the distance of the horizon. The square of 5 miles, multiplied by 8 inches, gives 416 feet; deducting the altitude of the light, 93 feet, we have 323 feet as the amount this light should be below the horizon.
p. 30
The above calculation is made on the supposition that statute miles are intended, but it is very probable that nautical measure is understood; and if so, the light would be depressed fully 600 feet.
Rowbotham appears correct in his last paragraph in that quote. Nautical men and the writers for nautical men would be reporting nautical miles, not statute miles.
In the video edby provided earlier, that YouTube presenter is also using nautical miles for a nautical matter of lighthouse ranges.
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Those weren't the quotes that I provided. However, it looks like Rowbotham is also using statute miles in those. Probably because the 8 inches per mile square rule applies to statute miles.
In ENAG Rowbotham does specify that he is converting to statute miles around those quotes and that nautical miles were likely intended.
From just above what you quoted we read:
Many instances could be given of lights being visible at sea for distances which would be utterly impossible upon a globular surface of 25,000 miles in circumference. The following are examples:--
"The coal fire (which was once used) on the Spurn Point Lighthouse, at the mouth of the Humber, which was constructed on a good principle for burning, has been seen 30 miles off." 1
Allowing 16 feet for the altitude of the observer (which is more than is considered necessary, 2 10 feet being the standard; but 6 feet may be added for the height of the eye above the deck), 5 miles must be taken from the 30 miles, as the distance of the horizon. The square of 5 miles, multiplied by 8 inches, gives 416 feet; deducting the altitude of the light, 93 feet, we have 323 feet as the amount this light should be below the horizon.
p. 30
The above calculation is made on the supposition that statute miles are intended, but it is very probable that nautical measure is understood; and if so, the light would be depressed fully 600 feet.
Rowbotham appears correct in his last paragraph in that quote. Nautical men and the writers for nautical men would be reporting nautical miles, not statute miles.
In the video edby provided earlier, that YouTube presenter is also using nautical miles for a nautical matter of lighthouse ranges.
I get it, I'm under the assumption as well that the nautical reference uses nautical miles and Rowbotham converted them to statute miles. And I think your logic is sound that he did so to more easily conform to the geographic distances.
There still is a lot that needs to be addressed. Similar to the US Coast Guard light range doc I previously referenced, I found this too:
'LUMINOUS INTENSITY AND RANGE OF LIGHTS GEOGRAPHICAL RANGE'
https://journals.lib.unb.ca/index.php/ihr/article/download/23979/27764
"The geographical range P„ would thus be a fixed value for a given light and a given ship.
In reality, however, Pe depends a little on atmospheric conditions. The various air strata are often of unequal temperature, pressure and humidity and consequently of a different refractive index, so that the luminous rays are not rectilinear but concave, the concavity being generally downwards. In these circumstances the light can be seen beyond its geographical range; frequently up to 40% farther, and occasionally even farther, and this phenomenon is difficult to predict."
There's tons of information in the article about how light range is calculated with meteorological and geographic data. Rowbotham is only using geographic data/calcs. I assume Findlay's book is based upon reports of observations not solely on what can be geographically calculated.
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So I went through the USCG New England section of the “Light List” I referenced earlier and randomly selected lighthouses I could find in Findlay’s book. Interesting results:
(Per Rowbotham, 16’ Observer height)
Findlay:
Cape Ann Light, Height: 98’ Range: 16 NM (18.4125 statute miles)
Geographic Range/Curve Calc: 23’ below horizon
US Coast Guard:
Cape Ann Light, Height: 166’ Range: 17 NM (19.5633 statute miles)
Geographic Range/Curve Calc: 23’ above horizon
Findlay:
Minots Ledge Light, Height: 84’ Range: 14 NM (16.1109 statute miles)
Geographic Range/Curve Calc: 0 above horizon, 0 below horizon
US Coast Guard:
Minots Ledge Light, Height: 85’ Range: 10 NM (11.5078 statute miles)
Geographic Range/Curve Calc: 56’ above horizon
Findlay:
Race Point Light, Height: 35’ Range: 11 NM (12.6586 statute miles)
Geographic Range/Curve Calc: 5’ below horizon
US Coast Guard:
Race Point Light, Height: 41’ Range: 14 NM (16.1109 statute miles)
Geographic Range/Curve Calc: 43’ below horizon
See if you can figure out what’s going on. I think the thrust here is that using just Rowbotham’s geographic calculation alone does not tell the whole story. It’s only one part of the equation. It’s a convenient argument, but it seems that’s all it is, convenient. It’s incomplete.
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I challenge whether Findlay was using nautical miles. He never specifies that he is, and I looked at other works of his where he uses geographic miles. So the jury is out. It could be that Rowbotham deliberately 'converted' in order to strengthen his case, who can tell.
In any case, this is a red herring and we are missing my main point above. When I calculate the theoretical range and compare to Findlay's UK data I get a correlation of 97.5%, which is very strong. When I use Findlay's non-UK data, the correlation collapses. This is prima facie evidence (1) that some of Findlay's data is corrupt and (2) that the section of his data set likely to be least corrupt, namely the UK data which in the days without email was the easiest to verify, is perfectly consistent with globe earth assumptions.
Tom needs to explain why the UK data so strongly correlates with globe earth.
Correlation (UK data) 97.5%
Correlation (non-UK data) 24.1%
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Tom needs to explain why the UK data so strongly correlates with globe earth.
Does he? You've found a correlation that allegedly applies to >0.05% of the Earth.
Why don't you explain why you find this statistically significant, and why you think correlation implies a causal link?
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First off, let me say that I have been reading these forums for a while now, and decided to jump into the fray.
I could not let the last reply from Pete stand due to its logical inconsistency.
Pete, you say that UK data does not imply a causal link since it represents a statistical insignificant amount of the geographical surface of the Earth.
Logically, this implies that the data that supports a flat earth is statistically significant and therefore proves the flat earth theory.
However, the reverse could be said that your flat earth data only represents a small amount of the geographical surface of the earth and therefore does not imply a causal link.
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Pete, you say that UK data does not imply a causal link since it represents a statistical insignificant amount of the geographical surface of the Earth.
I said neither of those things.
Logically, this implies that the data that supports a flat earth is statistically significant and therefore proves the flat earth theory.
No, this does not follow in the slightest. Asking someone to substantiate their claims does not make me an advocate for the opposite claim.
However, the reverse could be said that your flat earth data only represents a small amount of the geographical surface of the earth and therefore does not imply a causal link.
It could be said, and it would require the same substantiation that I currently await from our friend.
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Tom needs to explain why the UK data so strongly correlates with globe earth.
Does he? You've found a correlation that allegedly applies to >0.05% of the Earth.
I said above that it is possible that the UK is a part of a globe earth, but the rest of the UK part of a flat earth, but I think that's highly unlikely. What's your view?
Why don't you explain why you find this statistically significant, and why you think correlation implies a causal link?
All correlation as high as this requires some kind of explanation.
[EDIT] This page (http://condor.depaul.edu/sjost/it223/documents/correlation.htm) is a guide to how meaningful correlations are.Look for the entry in the table under 'physics'.
97.5% correlation is pretty high, no?
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Tom needs to explain why the UK data so strongly correlates with globe earth.
Does he? You've found a correlation that allegedly applies to >0.05% of the Earth.
Why don't you explain why you find this statistically significant, and why you think correlation implies a causal link?
I am pretty sure when you say "allegedly applies to >0.05% of the earth" combined with your question using the phrase "statistically significant" means that you currently are of the opinion that his data is not representative of the entire surface of the earth and that he needs to prove the link with something else. Which, obviously, you or Tom will refute again, ad nauseam. Yes, while you did not use that specific combination of words, language and word combinations are strongly indicative of what you mean to say, and given that you believe in a Flat Earth, this further shows what your words mean.
And yes, you are an advocate of the opposite claim. You believe in a Flat Earth. You believe that Rowbotham's data is representative of proof of a flat earth.
And where is the substantiation that Rowbotham's data is correct? This is a flat earth forum, therefore it should be substantiated.
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He is showing that there is a discrepancy between the two sets of data, and therefore one or the other is incorrect. Thats it.
Almost, but not quite. A high correlation always demands an explanation. It implies non randomness.
The very low correlation outside the UK suggests the Findlay's data is corrupt in some way. My guess: he was working in the UK at a time when universal travel was not common, and expensive, so he relied on agents outside the UK to supply information, and perhaps didn't pay them enough.
I am currently working through the whole data set to sort out these inconsistencies.
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I am pretty sure when you say "allegedly applies to >0.05% of the earth" combined with your question using the phrase "statistically significant" means that you currently are of the opinion that his data is not representative of the entire surface of the earth and that he needs to prove the link with something else.
Well, you can be as sure as you'd like. It's still false. I said what I meant, and I didn't mean things I didn't say.
And yes, you are an advocate of the opposite claim.
No, I'm not. Asking for someone to substantiate their claims is different from arguing the opposite. Especially when the issue is not binary.
You believe in a Flat Earth. You believe that Rowbotham's data is representative of proof of a flat earth.
Please could you point me to an instance of me agreeing with Rowbotham's data? My beliefs are quite divergent from Rowbotham.
And where is the substantiation that Rowbotham's data is correct? This is a flat earth forum, therefore it should be substantiated.
That appears to be largely unrelated to my own request, and I'm not sure flooding this board with tu quoques is particularly helpful.
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Pete,
My apologies. I assumed, seeing as how you and Tom are the most vocal and prominent members of the website, that you would be supportive in using Rowbotham as supporting evidence in the earth being flat. I stand corrected.
And again his only claim is that there needs to be an investigation as to why one set of data has a high correlation and another does not. He does not have to substantiate anything, he already has shown it. You are inserting irrelevancy by asking him to prove why 0.05% of the earth is statistically significant for the whole, when that is not what he was setting out to do.
And yes, this is unrelated to your request due to the fact that your request is unrelated to the subject matter.
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You are inserting irrelevancy by asking him to prove why 0.05% of the earth is statistically significant for the whole, when that is not what he was setting out to do.
He is demanding that we explain a tiny subset of the data. I ask why he's focusing on that tiny subset. I do not want to assume his reasoning, hence the question.
If you really wanted me to guess a reason, I would speculate confirmation bias - the tiny speck on the map confirms his hypothesis, and nothing else does, so let's focus on favourable data. I'd rather have him explain himself than assume that - I think that's only courteous.
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You are inserting irrelevancy by asking him to prove why 0.05% of the earth is statistically significant for the whole, when that is not what he was setting out to do.
He is demanding that we explain a tiny subset of the data. I ask why he's focusing on that tiny subset. I do not want to assume his reasoning, hence the question.
If you really wanted me to guess a reason, I would speculate confirmation bias - the tiny speck on the map confirms his hypothesis, and nothing else does, so let's focus on favourable data. I'd rather have him explain himself than assume that - I think that's only courteous.
I already explained this in my earlier post. As I live in England, I am interested in whether England is flat or not. Evidence from Findlay's data strongly suggests not flat. Rest of world, not too bothered.
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I already explained this in my earlier post. As I live in England, I am interested in whether England is flat or not. Evidence from Findlay's data strongly suggests not flat. Rest of world, not too bothered.
That's extremely peculiar. At such small scale, you can only really hope to infer how hilly the area is. Let's say it turns out that England is slightly convex - how does that help this particular discussion?
And, if it doesn't, I hope you can guess what I have to say next.
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I already explained this in my earlier post. As I live in England, I am interested in whether England is flat or not. Evidence from Findlay's data strongly suggests not flat. Rest of world, not too bothered.
That's extremely peculiar. At such small scale, you can only really hope to infer how hilly the area is. Let's say it turns out that England is slightly convex - how does that help this particular discussion?
Remember we are talking about a wide coastal area around England, i.e. about the sea being 'hilly', or rather having a consistent positive curvature. That would be significant, no? Of course this could be a peculiarity of the English coastline, but would be something FE needed to explain.
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I have just checked out the 1879 edition of A Description and List of the Lighthouses of the World where some of the numbers have changed. Mostly they change the underestimates of visible distance to something closer to the expected value. Sometimes they change overestimates to something close. Very occasionally they make the discrepancies worse.
My point therefore remains that this work (on which Rowbotham relied) is not entirely reliable.
There is also an 1887 edition, which is not available online, but is in the library and I shall check out when next there.
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Further, the 1879 edition states
The distance to which the principal lights are visible is generally limited by the horizon. There is no doubt but that they might be seen to very great distances, even 60, 80, or even 100 miles, if sufficient elevation could be gained to view them from. It is considered by many that 250 feet is the maximum height necessary or advisable, which will give an horizon 18 miles distant and, by ascending the rigging, 20 miles off.
adding that the table gives miles visible to an observer 14 feet above the sea. It then gives a table 'given in the grand work on the Skerryvore Lighthouse by Alan Stevenson esq, which lists the distance to the horizon in both statute and nautical miles'.
I have calibrated the table and find it gives exact results using the formula d = 1.3228 x sqrt(h), where d is distance to horizon, h is height of observer.
What do we conclude? Well first that Findlay and co were assuming a spherical earth in their calculations. Second, that it is odd that Rowbotham was using their book as proof of a flat earth. The logical conclusion is that the exceptions that Rowbotham he found were simply typographical or reporting or calculation errors, some of which were corrected in the 1879 edition, some were not.
[EDIT]For those who are interested, the book by Stevenson to which he refers is here https://books.google.co.uk/books?id=u-hhAAAAcAAJ, and the table is on p.329. Stevenson mentions the formula d = sqrt(7h)/2, and you will notice that sqrt(7)/2 = 1.3228, the number I calibrated above.
You may also remember that Robert Louis Stevenson, the Treasure Island guy, Captain Hook and all that, came from a family of lighthouse engineers. He was the nephew of Alan. He wasn't so good at lighthouses, so he wrote stories instead.
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Of course this could be a peculiarity of the English coastline, but would be something FE needed to explain.
Only if we assume the data is correct. Given that a vast majority of it is not, I see no reason to make that assumption. You're conflating "correlation with RET" with "correctness".
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Of course this could be a peculiarity of the English coastline, but would be something FE needed to explain.
Only if we assume the data is correct. Given that a vast majority of it is not, I see no reason to make that assumption. You're conflating "correlation with RET" with "correctness".
I agree there are problems with the data. See my later posts immediately above.
However correlation still needs explanation, and there I disagree with you. Correlation implies lack of randomness, and lack of randomness always requires explanation.
[EDIT] You also mentioned a 0.05% figure somewhere above. Where did this come from?
[EDIT] Oh I see. You divided area of UK by area of world (assuming latter is correct) giving 0.05%. But immediately above you say "Given that a vast majority of it [i.e. the data] is not". But the percentage of Findlay's book devoted to UK data is not 0.05%. Oh dear.
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In fact 11% of Findlay's data is devoted to UK (i.e. England and Scotland) lighthouses.
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Correlation implies lack of randomness, and lack of randomness always requires explanation.
2*2=2+2, therefore for a certain subset of numbers, addition is the same as multiplication. Those who propose that these operations are different must be able to explain this correlation, even though it's not in any way significant or remarkable.
Correlation is a perfectly valid outcome of randomness or coincidence. Indeed, it's exactly as likely as any other outcome. You're attempting to force a logical fallacy through.
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As for 0.05%, I said this:
You've found a correlation that allegedly applies to >0.05% of the Earth.
Of course, I meant <0.05%, but hey-ho, this isn't the first time I've failed at basic typing ;)
Nonetheless, it was you who claimed that your data shows the UK is convex while the rest of the world is not. I can't be held responsible for your own claims.
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My claims were about data, not area. See this post https://forum.tfes.org/index.php?topic=11728.msg178123#msg178123.
Also this post https://forum.tfes.org/index.php?topic=11728.msg178183#msg178183.
You say
He is demanding that we explain a tiny subset of the data.
But it is not a ‘tiny subset of the data’, as I have explained. You are confusing percentage area, by percentage of data. Keep on digging that hole.
2*2=2+2, therefore for a certain subset of numbers, addition is the same as multiplication.
Yes for a very small data set, in this case one, correlation is of no statistical significance whatsoever. For a large set, in my case I used 54 items, it is highly significant. Another way to approach it is via the concept of ‘standard deviation’. How far does the expected amount (RE calculation) differ from the observation? In the case of Findlay’s UK data, 1.67 miles.
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You keep asserting that it's significant with no qualification. I have already asked you to substantiate that. Further unqualified assertions are unlikely to advance your cause.
Also, if you want to shift the goalposts to percentage of data points (despite the obvious flaws of that approach), even after you've successfully made your case you'll still need to justify your reasoning for ignoring the vast majority of data points you personally find inconvenient. Whether you fight against 99.5% of the Earth's area or 90% of the data points collected is largely irrelevant - it's nothing but meaningless semantics that ignores the actual issue.
Start defending your position.
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You keep asserting that it's significant with no qualification. I have already asked you to substantiate that. Further unqualified assertions are unlikely to advance your cause.
Also, if you want to shift the goalposts to percentage of data points (despite the obvious flaws of that approach), even after you've successfully made your case you'll still need to justify your reasoning for ignoring the vast majority of data points you personally find inconvenient. Whether you fight against 99.5% of the Earth's area or 90% of the data points collected is largely irrelevant - it's nothing but meaningless semantics that ignores the actual issue.
This is essentially what Bresher's point was in describing what Rowbotham did. Bresher claimed that, after reviewing the reference source, Rowbotham, was, in your words, 'ignoring the vast majority of data points he personally found inconvenient.'
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[…] if you want to shift the goalposts to percentage of data points
I already stated above, citing two previous posts, that ‘my claims were about data, not area’. So I am not ‘shifting goalposts’. The whole of this thread is about the data that Rowbotham and others have used to support their claim of a flat earth, all of which (as far as I can tell) is sourced from Findlay 1862.
You keep asserting that it's significant with no qualification. I have already asked you to substantiate that.
You did, and I replied (https://forum.tfes.org/index.php?topic=11728.msg178207#msg178207) citing this (http://condor.depaul.edu/sjost/it223/documents/correlation.htm) as evidence. Or look in almost any standard statistics textbook that deals with correlation. [EDIT] I used 54 data points for the UK. Most textbooks state that 20 will suffice.
I will deal with the allegations of cherry-picking in the next post.
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… even after you've successfully made your case you'll still need to justify your reasoning for ignoring the vast majority of data points you personally find inconvenient. Whether you fight against 99.5% of the Earth's area or 90% of the data points collected is largely irrelevant - it's nothing but meaningless semantics that ignores the actual issue.
Start defending your position.
My position is that there are many clear problems with the data in the 1862 edition of the book ‘Lighthouses of the World’, which Samuel Rowbotham cites in Earth not a Globe (http://www.sacred-texts.com/earth/za/za14.htm), experiment number 9.
First problem. Rowbotham cites Findlay as defining the visible range as the minimum distance to which the light can be seen in clear weather from a height of 10 feet above the sea level’. This is what the 1862 ed. states, p. 32. However the 1879 edition p.31 states ‘The distance of the sea-horizon due to that elevation [of the lighthouse], is stated to be the distance it may be seen from the deck of an ordinary vessel, 14 feet above the sea’
This discrepancy affects every calculation in Findlay’s book.
Second problem A number of figures given in the 1862 edition were revised in the 1879 edition, some of them cited by Rowbotham. For example, Rowbothamsays ‘The Light on Cape Bonavista, Newfoundland, is 150 feet above high water, and is visible 35 statute miles [=30 NM]. These figures will give, on calculating for the earth's rotundity, 491 feet as the distance it should be sunk below the sea horizon’. This calculation is correct assuming the figures given in the 1862 ed. p.111. Howeverthe 1879 ed., p. 157, gives 16 miles, not 30. If we assume the observer is 16 feet above water, not 10, and assume nautical miles are meant (Findlay never says), this is less (not more) than the RE calculation.
Rowbotham writes ‘The Port Nicholson Light, in New Zealand (erected in 1859), is visible 35 statute miles, the altitude being 420 feet above high water. If the water is convex it ought to be 220 feet below the horizon’. But the 1879 edition (p.155) gives a height of 450.
Of course the 1879 edition could be wrong and the 1862 correct, but this contradicts the usual state of things where later editions correct mistakes in earlier ones, and in any case it casts doubt on the reliability of Findlay’s data, on which Rowbotham’s claims depend.
Third problemWhen we split Findlay’s data into UK (11%) and non-UK (89%) data, we find a significant correlation (97.5%) between RE and Findlay UK estimate of visible range, and a very low (24%) correlation for non-UK.
Pete has challenged my claim of ‘significant’ for the 97.5% correlation. This is for over 50 data points, I refer him to any standard textbook on statistics on this point.
He has also claimed I am cherry picking the data. But my position, as stated above, is that there are clear problems with the data that Rowbotham was using (i.e. Findlay’s 1862 data). Either
(1) All the data, UK and non-UK, is weak. Then I have my case. Rowbotham was basing his claims on weak data.
(2) Some of the data is weak (the non-UK data), other data is strong (the UK data). This is my hypothesis. Findlay was almost certainly relying on agencies for the non-UK data, and weak data is what you often get with agencies. But if the UK data is strong, that supports the RE position, moreover Rowbotham’s case collapses.
(3) The non-UK data is strong, the UK data is weak. This contradicts the strong correlation found in the UK case. For the non-UK case we have merely weak correlation, which proves nothing.
(4) Both data sets are strong. But in that case we have the sea around the UK being convex, the sea around all other countries flat. Pete has talked about the UK being ‘hilly’, but the last time I looked, hills only exist on solid ground. We are talking here about the surface of the sea here, not the land, and the only ‘hills’ on the sea are temporary ones. I suppose it could be argued that there is a sort of permanent swell surrounding the British coastline, but that is implausible even in an FE state of mind.
I rest my case.
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(3) The non-UK data is strong, the UK data is weak. This contradicts the strong correlation found in the UK case. For the non-UK case we have merely weak correlation, which proves nothing.
Your personal credulity is not applicable here. Correlations prove nothing, and your attempt to categorise them into correlations you like and correlations you dislike is laughable.
I rest my case.
I take it we're ready for the AR move, then? Your entire argument relies on correlations implying causation, and on the fact that you personally think some things are likely. A perfect exhibit for the Logic Museum, indeed.
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(3) The non-UK data is strong, the UK data is weak. This contradicts the strong correlation found in the UK case. For the non-UK case we have merely weak correlation, which proves nothing.
Your personal credulity is not applicable here. Correlations prove nothing, and your attempt to categorise them into correlations you like and correlations you dislike is laughable.
As I said, look at any textbook entry that deals with data size and correlation. Not my 'personal credulity'.
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As I said - trying to leap from correlation to a causal relation is laughable. Revise your argument or justify it.
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As I said - trying to leap from correlation to a causal relation is laughable. Revise your argument or justify it.
Nowhere in any of this thread did I use the word 'causation' or its cognates. I said that any high correlation requires an explanation, for correlation implies a degree of non-randomness.
You are the only person talking about causal relations here.
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Nowhere in any of this thread did I use the word 'causation' or its cognates.
I refer you to my previous point on meaningless semantics (https://forum.tfes.org/index.php?topic=11728.msg178317#msg178317), and how effective they are as a distraction strategy.
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Nowhere in any of this thread did I use the word 'causation' or its cognates.
I refer you to my previous point on meaningless semantics (https://forum.tfes.org/index.php?topic=11728.msg178317#msg178317), and how effective they are as a distraction strategy.
Perhaps we could refer this dispute on a technical point to a referee here. If no one here I have plenty of academic colleagues who could act as such. The exam question is whether a correlation of 97.5% over a sample size of 54 requires an explanation. [EDIT] I am happy to increase the sample size, plus include the corrections in the 1879 edition (see above), and publish the evidence. Up to you.
By all means consign to 'angry ranting about correlation', but then we have the evidence that you have done so.
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Nah, I apologise about the AR posturing and I take it back. I strongly disagree with your point, and I do think it relies on fallacies, but I don't doubt your genuine intentions. From a moderation standpoint, there's nothing wrong with this thread.
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I strongly disagree with your point, and I do think it relies on fallacies ...
I will try to explain better. We have a function f(h) -> v, where h is lighthouse height, v is visible distance, and we are trying to test ‘how well’ the function predicts the visible range given by observers.
Suppose that in scenario 1, our function returns a random number uniformly distributed between 0 and 45 miles, where 45 miles is the maximum range that any light can be seen due to atmospheric conditions. I think you agree that would not be a very useful function. It predicts nothing, because it is random, and that was my point earlier about randomness.
In scenario 2, by contrast, suppose that the maximum difference either side is 5 miles, that 80% of the observations are within 2 miles of the amount predicted by our function, and that 70% are within 1 mile.
Then we don’t need adjectives like ‘good’ or ‘strong’. We don’t even have to know how the function works, or whether it is consistent with round earth or whatnot. We just know that, given the height, there is an 80% chance of being within 2 miles of the observation, and a 70% chance of being within 1 mile.
Does that work better for you?
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Except that when using nautical miles it goes against your theory.
Using statute miles, in a nautical work, to provide evidence for your theory is deceptive and you should have provided both versions rather than choosing to deceive through misrepresentation.
If the measurements presented were miles then he should have used miles. If you want to know where some distance in nautical miles falls along the trendline simply convert that distance into miles and find the x coordinate whose output is that distance in miles you are using. Converting his use of miles to nautical miles would yield the same results as the actual distance is still the same and as long as the conversion is done correctly the equivalent distance in some other unit will by definition still be the same distance. If something is 1000m away and you want it converted to kilometers, that object is still 1000m away, only now your gragh has it as 1.000km. You are literally asking him to apply one additional coefficient which graphically appears as a compression or stretch unless a different scale is used to compensate; if the latter is true the two graphs will be identical
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Except that when using nautical miles it goes against your theory.
Using statute miles, in a nautical work, to provide evidence for your theory is deceptive and you should have provided both versions rather than choosing to deceive through misrepresentation.
If the measurements presented were miles then he should have used miles. If you want to know where some distance in nautical miles falls along the trendline simply convert that distance into miles and find the x coordinate whose output is that distance in miles you are using. Converting his use of miles to nautical miles would yield the same results as the actual distance is still the same and as long as the conversion is done correctly the equivalent distance in some other unit will by definition still be the same distance. If something is 1000m away and you want it converted to kilometers, that object is still 1000m away, only now your gragh has it as 1.000km. You are literally asking him to apply one additional coefficient which graphically appears as a compression or stretch unless a different scale is used to compensate; if the latter is true the two graphs will be identical
I appreciate that, but it depends whether our function f(x) gives results in statute or nautical miles. We don't know exactly which units Findlay was using, and Rowbotham actually concedes this.
I did the calculation both ways and actually makes very little difference. That is because the correlation function is implicitly looking at deviations from average values.
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Does that work better for you?
No. No amount of hand-waving will clear your logical fallacies and your attempt at overfitting a tiny subset of the data you're considering. You have to correct your errors, not restate them until I get bored.
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The comment about causation and correlation is another example of “heads I win, tails you lose” reasoning.
The globe model can predict how far one should be able to see objects from if we know their height above sea level. Now, in real life there may be refraction effects which make it harder to predict exactly but some correlation between the maximum distance an object can be seen and the prediction from the model would build confidence in the model.
Rowbotham casts doubt on the model by claiming that there are lots of sightings from much further than predicted by the model. The counter argument presented was that the non-UK data seems to be unreliable and from a different source to UK data and the UK data does actually correlate quite well with the globe earth model.
Then Pete swings in with “correlation doesn’t imply causation”. Now, he’s right but here we are testing a model which claims a correlation. The criticism is that the correlation doesn’t exist, ergo the model is wrong. If someone shows that a correlation does exist for a section of the data and that other data had a different, possibly less reliable source, then that can’t just be dismissed as meaningless
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then that can’t just be dismissed as meaningless
I agree - but unfortunately that's the situation we were presented with. I pointed out that this is likely a case of overfitting, and edby informed us that he likes England because he lives there (https://forum.tfes.org/index.php?topic=11728.msg178246#msg178246). Any meaningful discussion died at that point.