[Tontogary]

Ok here i am going to try to hold a discussion and debate the claims made in EnaG regarding the horizon always rising to eye level.

I am not trying to derail any other threads, there is an excellent experiment underway to try obtain a photographic proof of this or not, but this thread is about examining EnaGs claims, and looking at the chapters where he makes the claims and looking at the different ways he attempt to Prove it.

The hypothesis is a cornerstone of many of the claims made in EnaG, and is used as a proof of something, ie “X must be true as the horizon always rises to eye level” or “Y is proven as the horizon must rise to eye level”

To start with I will list down the chapters and experiments that are used to prove this hypothesis, and then examine them in a bit more detail, and trying to see if they stand up to scrutiny.

The following are the chapters and experiments that deal with showing how it works, or proving the claim,

Chapter II
Experiments 10, 11, 15.

Chapter XIV
Tangential Horizon


These are the chapters and experiments that he uses to explain the hypothesis, and where he makes studies and measurements as such.
Only in Ch II experiment 11 and 15 does he use instruments to back up the claims, Whilst elsewhere he uses newspaper articles and line drawings as evidence.

Whilst there are other parts of EnaG that use the hypothesis as a proof, they do not advance or forward the knowledge of why that is, other than to state that is has been shown to be so.

I will take each experiment or chapter and deal with it separately.

[Tontogary]

Chapter II experiment 11.

This is the first real go at explaining the idea that the horizon rises to meet eye level, and pretty much consists of eye witness accounts, taken from other publications, newspapers or periodicals, that repeat the writings of the ballonists who ascended at different heights on different balloons.

However at the start of the chapter he describes what is seen at sea;

“If he takes a position where the water surrounds him--as, on the deck or the mast-head of a ship out of sight of land, or on the summit of an island far from the mainland--the surface of the sea appears to rise up on all sides equally, and to surround him like the walls of an immense amphitheatre. He seems to be in the centre of a large concavity--a vast watery basin--the circular edge of which expands or contracts as he takes a higher or lower position. This appearance is so well known to sea-going travellers that nothing more need be said in its support”

These remarks do nothing other than say, People say it is so, so it must be! I am a sea going traveller, of the last 33 years, and this phenomena is not well known to me! Or any of my colleagues, so at this point his arguments do not stand up to any logical test, or to the test of sea going travelers i have met, and should be treated with caution, and a rather large pinch of salt.

The rest of his “experiment” is devoted to copying the words of 6 people who had ascended in balloons, with he highest of them 2 miles high (although no description of how this was measured is found) and the accounts that are dated from the time they appeared in print in their original publications are from between 16 and 24 years prior to publication of the second edition of EnaG. That there were only very few accounts are described below;

”but the appearance from a balloon is only familiar to a very few observers, and therefore it will be useful to quote the words of some of those who have written upon the subject”

And it is not completely sure that all accounts are actually written by balloonists, and may be only attributed to them.

In any case with the highest mentioned altitude of 2 miles, the dip of the horizon would be calculated to be 1 degree and 40 minutes of arc, which to an observer with the naked eye, flying high, possibly in awe of his surroundings, it is easy to see how they could not have possibly detected such a tiny amount of dip with their eyes alone, and most of the passages are rather poetic in the descriptions of what is observed.

At no time are any instrument measurements taken, or referred to, which brings into question the accuracy of the human eye observations.

It has to noted that there were hundreds of ballon flights before the publication of EnaG second edition, notably in 1850s through to 1880,  and to use just a few poetic descriptions that do not use any instruments, to make the argument of the horizon rising to eye level is not particularly scientific.

The results of chapter 10 are therefore completely subjective, and should be not believed to be accurate, considering we have had more than 150 years of flight since, with instruments such as aviation sextant with artificial horizons that are capable of recording the dip of the horizon at altitude.

Personally I would tend to dismiss “experiment” 10, as a series of annecdotal third hand accounts, (definitely not an experiment) that does nothing to prove that the horizon rises to eye level. It does not follow a Zetetic process as far as i can see.

[hexagon]

In principle you only have to go for his description in Chapter XIV. There he defines the angle of about 1° under which perspective lines go away from the vanishing point. If you read how he derives this conclusion, it is more than obvious, that mixes this up with the effect of optical resolution. Basically he gives perfect description, how optical resolution effects the perception of far away objects and how this changes if you use a tool like a telescope.

The other interesting point is, when he correctly describes what happens if you look through a long tunnel. He says, that the exists of the tunnel shrink to points and look like distance stars. That's a very nice description of the isotropic effect of perspective. But besides this tunnel observation, he restricts the effect perspective to the vertical plane. E.g. ships only shrink in the vertical direction, but not in the horizontal direction. The same for the sun. This is inconsistent with his own descriptions, examples and explanations.

Interestingly, the flat-earth believes go beyond this up to now. They use horizontal perspective only for things like railway tracks or streets. But never for buildings, mountains, ships, etc. far away at the horizon. Same still for the sun (while stars shrink inconsequentially isotropic to points). Most obviously this error is made in the typical "look a long a wall" example. From the point of perspective this is a mixture of horizontal and vertical effects of perspective. But they use it only as example for the vertical effect. It's really hard to follow way of thinking.         

[Tontogary]

In was going to get round to chapter XIV, and was going to take each “experiment” at a time, to see if there was any way that the y could be defended as proven, which i think is not the case.

Interestingly this thread came about when Tom insisted that EnaG showed that instruments were not necessary to prove the horizon rises to eye level, and that all of his experiments were fail/pass, prompting me to look again at what was written.

Experiment 11 Is the next one I was going to tackle..........

[hexagon]

I only thought it is easier to go for the origin of all this. If the premise is already wrong, it is self evident that any conclusions drawn from it are also wrong.

[Tontogary]

I only thought it is easier to go for the origin of all this. If the premise is already wrong, it is self evident that any conclusions drawn from it are also wrong.

I appreciate the comments though, as this is after all a discussion. Hopefully some FEers will engage here as well.

Your comments on Chapter XIV are along the lines of what i was thinking, and are welcome in any case.

[rabinoz]

Here is a much earlier post on this topic:

Baloney. Even Rowbotham admits that this isn't true (perhaps inadvertently). From the very first paragraph of EnaG: Tangential Horizon:

IF a theodolite is placed on the sea shore, "levelled," and directed towards the sea, the line of the horizon will be a given amount below the cross-hair, and a certain "dip" or inclination from the level position will have to be made to bring the cross-hair and the sea-horizon together. If the theodolite is similarly fixed, but at a greater altitude, the space between the cross-hair and the sea horizon, and the dip of the instrument to bring them together, is also greater. From the above, which is perfectly true...

I underlined the relevant part. If the horizon does actually "ascend to eye level" regardless of height, then you wouldn't have to incline the theodolite at all. He goes on to argue that this doesn't prove that the earth is curved, but this is beside the point.

Awwww, SNAP!!
This is what happens when you tell us to go read your ancient rubbish, Tom!  We actually READ it, and UNDERSTAND it, and use it to refute you.  It is unfortunate for your cause that Rowbotham is so clear in his writing, it leaves no room for misinterpretation of his meaning.

Were you guys capable of reading a complete paragraph you would have found the following:

From the above, which is perfectly true, it has been concluded that the surface of the earth is convex, and the line of sight over the sea tangential. As a proof that such is not the case, the following experiment may be tried:--

How embarrassing for you. Apparently you do not look very deeply into anything. Rowbotham provides contradicting experimental evidence and goes on to correctly identify the effect as an effect of the lens. I would suggest actually reading the material.

Note that Tom Bishop claimed that:

Rowbotham provides contradicting experimental evidence and goes on to correctly identify the effect as an effect of the lens. I would suggest actually reading the material.

Rather than Rowbotham providing "contradicting experimental evidence" I would assert that all Rowbotham did was cover up the very small dip angle to the horizon by discarding the telescope.

[hexagon]

Hm, the explanation of lenses in EnaG only shows a complete lack of knowledge how a lens works, how optics works and so on... Maybe someone should do some research and read a standard book like Born/Wolf "Principle of Optics"...

[Tontogary]

Ok, Now having dealt with “experiment” 10, we will look at “experiment” 11, and i will do this in a few bites as it is a relatively long chapter.

At the start he uses the East pier at Sussex, as well as a balloon to try to show the dip of the horizon does not exist.
The pier observation has the height of the observer at 34 feet from the water, and he says he uses a “large wooden quadrant” which is essentially a plumb bob with a wooden protractor.
https://en.m.wikipedia.org/wiki/Quadrant_(instrument)

He claims that he could not measure the dip of the horizon therefore it does not exist.

The calculation and tables for a height of eye of 34 feet gives a dip of the horizon of 5.7 arc minutes, or less than 1/12 of a degree. This would have been pretty much impossible to see with the naked eye, and as well as the problems of making the plumb bob steady in any breeze, renders the above observation pretty much useless.

The second “observation” relates to an observation from a balloon, and he claims that such a dip
“would be so great that the aëronaut could not fail to observe it; instead of which he always sees it "on a level with his eye," "rising as he rises," and "at the highest elevation, seeming to close with the sky."
This is dealt with in the discussion of “experiment” 10, And will result in a dip of the horizon of 1 degree and 40 minutes, which might have been possible to measure with a quadrant, but of course he is relying purely on an account taken third hand from a publication some years previously, so it cannot be verified.

He also goes on to list a few places that he has visited and claims to have taken his plumb bob and wooden set square to and says he did not observe any dip, such as;
1, Arthurs seat (elevation 251M ) dip would be 28arc minutes, (also pretty windy, and a very small arc of the horizon to view),
2, Hills near Brighton racecourse, (no sure as to height as he did name them), but have taken the highest hill nearby at 120M elevation, Dip of 20 arc minutes.
3, Some hills on the Isle of Wight, (Again none named), but i have taken some of the highest and rounded up to 250M, Dip of 28 arc minutes,
4, Steep Holm, Elevation 78M, Dip 15.7 arc minutes.
5, Hills near Plymouth, 125M (Rame head) Dip 20 arc minutes
6, Irelands Eye, Elevation 32M Dip 10 arc minutes,

Above is a list of some of the places he visited, and claimed to have taken readings with his plumb bob and quadrant, and all of them suffer the same issue, they are ALL exposed locations, and the UK is not known for its still and calm airs! And as can be seen, low elevations, with low dip arcs, and as the equipment used is pretty imprecise, it is easy to see that he could probably not have made any meaningful observations of those dip angles.
He was also (i would suggest) suffering from confirmation bias, he was looking for zero dip, therefore he found none using an imperfect device.

More to follow;

[Bobby Shafto]

The calculation and tables for a height of eye of 34 feet gives a dip of the horizon of 5.7 arc minutes, or less than 1/12 of a degree. This would have been pretty much impossible to see with the naked eye, and as well as the problems of making the plumb bob steady in any breeze, renders the above observation pretty much useless.

I can attest to that.

In my garage, the plumb bob is great for leveling my instrument. But I have yet to find it useful in the open, near the coast.
I tried the simple homemade clinometer, using a plumb bob and a quality protractor. But like you predict, any kind of breeze makes it nearly impossible to use so I scrapped that idea.

[MCToon]

Excellent thread so far.

Let's all remember this: Useful experiments are confirmable by third parties.  Detailing the test conditions and equipment are vital.  Without this the experiment is must less useful and less trustworthy.

[Tontogary]

Ok further on in experiment 11 he looks at the idea of using a theodolite for taking the dip of the horizon, and he says it shows an apparent dip.

He says he has used different instruments and has seen the same thing each time, always shows the horizon is below the cross hairs, but by different amounts.

He then goes on to describe an experiment where he uses a levelled tube instead, which has no lenses, and says

“He therefore obtained an iron tube, about 18 inches in length; one end was closed, except a very small aperture in the centre; and at the other end cross-hairs were fixed. A spirit level was then attached, and the whole carefully adjusted. On directing it, from a considerable elevation, towards the sea,
and looking through the small aperture at one end, the cross-hair at the opposite end was seen to cut or to fall close to the horizon”

Now the diagrams are a bit disingenuous as they both show a ship, but the theodolite diagram shows a ship on the horizon, and the “iron tube” view shows the same ship at the same size.

Now he claims that all lenses have what he calls “collimation” error which is caused by the lens, and makes the horizon appear below where it should, yet he makes no mention of why if this is true the manufacturers dont simply adjust for it, or even why it ALWAYS appears to be below the horizon.

Also his view down the iron tube is not magnified, and he says the cross hair is on “or close” to the horizon, yet at most sensible elevations, with the naked eye, dip would not be determined, and would be close to zero, and not really observable.

As an aside, and taking into account other threads on this site, it is remarkable that he never once says that the horizon is not clear or is being fogged out, or is hazy in this examination. Surely not to the same degree as some responses on here do.

[hexagon]

The problem is always the same, he doesn't understand how a lens works and attaches random properties to it that just fit to neglect the outcome of the experiment. For him a lens/telescope only works fine if he explains the recovery effect of objects behind the horizon. It's not that in this case he has a better understanding of it, but there it fits to his view on the world...

[edby]

Now he claims that all lenses have what he calls “collimation” error which is caused by the lens, and makes the horizon appear below where it should, yet he makes no mention of why if this is true the manufacturers dont simply adjust for it, or even why it ALWAYS appears to be below the horizon.

That's the one that puzzles me. Suppose the lens makes every point whatsoever proportionately lower relative to the spirit level than it should be. Then that defeats the purpose of the instrument. You first twiddle the dial which adjusts the angle of the tube, until the bubble on the level is exactly in the centre. Then every point you can see on the horizontal crosshair, will be 'on the level', but this is because the instrument is carefully calibrated at the factory.

Or suppose that nearby objects are level, but distant ones are not, i.e. appear lower than they should be. This would not be explained by the lens, but by a property of the light, i.e. by concave refraction.

I have asked about concave refraction here before, but no one has given a satisfactory answer.

[hexagon]

I have asked about concave refraction here before, but no one has given a satisfactory answer.

What d you mean by "concave refraction"? "Concave" is a property of the lens, not the refraction. The refracted index difference of both sides of an interface determines if the angle of refraction is larger or smaller than the incident angle. But that effect you don't call "concave" or "convex".

A lens as it is used in a telescope or similar instruments is usually a spherical lens, that means it's surface is part of sphere. Therefore it's optical properties are isotropic with respect to center of the lens (the optical axis). There can't be just a vertical distortion. That would only be possible if the telescope as such is not well manufactured or misaligned. But this would be visible in the same way for objects close by or far away.     

[Max_Almond]

I think he means a line of sight that dips down and then back up.

I guess that's not an impossibility. But probably very, very rare.

[edby]

I think he means a line of sight that dips down and then back up.

I guess that's not an impossibility. But probably very, very rare.

That's what I meant. That hypothesis would explain why the horizon appears to be lower than it would be in FE. It would also explain why ships 'disappear' over the horizon. However, seems to be inconsistent with the actual facts about refraction, as well as other things FE proposes.

[Max_Almond]

Here are the best papers on refraction I could find when I was looking into it last year:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JD014067

https://www.metabunk.org/attachments/practical-formulas-for-calculating-the-refraction-coefficient-pdf.28444/

And here's a refraction simulator you can play with:

https://www.metabunk.org/mirage/

See if you can find any evidence or possibility for "upwardly curving refraction" that may imitate the earth's curvature.

[edby]

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JD014067 I think I roughly follow this. It says that the coefficient of refraction k is the ratio between the radius of the Earth R and radius of the line of sight r.
   

k  =  R/r

A positive sign of the refraction coefficient indicates a convex shape of the light ray, i.e. following the Earth's curvature. If I understand, a k of 1 means the refraction = curvature of earth, multiples of that mean more curved.

But note:

Here, the temperature of the air strata, particularly its vertical temperature gradient, is strongly influenced by daily variations in the surface temperature. This may result in either negative or positive values of the refraction coefficient k near the ground ..

And figure 1 indeed shows concave light!

Note that the path of light is bent toward the ground (negative refraction coefficient k), which is a typical situation for observations near the surface in the summer.

[edby]

That said, the other paper suggests that negative k is abnormal, and that if you take readings off the ground, and about mid morning, you should expect the standard k of 0.13.

Who volunteers to explain this to Tom?