Offline SiDawg

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Perspective in 'Earth Not a Globe' contradicts itself
« on: May 24, 2018, 02:28:24 AM »


ENAG shows this representation for how humans perceive objects disappearing in to the distance towards a vanishing point (drawing perspective lines to show the effect):


It follows that one can also draw a perspective line on the bottom of the lamp, as it clearly follows the same rules: in other words, the lamp post gets smaller, and the actual lamp 'head' gets smaller, as clearly shown in the diagram:


ENAG then goes on to show how the sun sets because it too approaches a vanishing point:


However, in this image, they have either forgotten or failed to show the size of the sun descreasing, just like the head of the lamp does


Is there some "exception" rule for the top image vs the bottom image? Is ENAG choosing not so show the sun shrinking for the purposes of the diagram? Given the diagram is meant to describe what we see in reality, then which version is more correct in reality? When you view a lamp in the distance, does the light/head part of the lamp stay exactly the same size while only the post shrinks to the vanishing point?

ENAG is saying in the top image, that images shrink towards a vanishing point, yet it's also saying that objects DON'T shrink towards a vanshing point in the bottom image, and that somehow light can hold information about what should shrink and what shouldn't shrink? Aparently the height of an object can shrink without the object itself shrinking? If the top of the lamps had their posts removed, and were sitting on the ground, would they not still shrink in the distance? How are they any different from the sun: the sun is just a lamp without a post, yes?

All base images from 'ENAG' courtesty "Zetetic Astronomy - Earth Not a Globe" (ENAG), by 'Parallax' (pseud. Samuel Birley Rowbotham), [1881], at sacred-texts.com. Red lines added to images but all rights retained as per original
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Offline hexagon

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #1 on: May 24, 2018, 07:58:23 AM »
As far as I understood, there are some differences how perspective acts on objects on or close the ground and celestial objects. It also makes a difference, if the object is a light source or not. Cause light sources do not shrink. In your case, the sun is a light source, so it will not shrink. The lamp post will also shrink, but the lamp it self not (at least if it is dark and the lamp is switched on).

Interesting question is, how should you treat the moon? Is it a light source, therefor it is not shrinking as the sun? But if is only visible because it is reflecting light, does it still behaves like a light source? 

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Offline MCToon

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #2 on: May 24, 2018, 11:47:49 AM »
As far as I understood, there are some differences how perspective acts on objects on or close the ground and celestial objects. It also makes a difference, if the object is a light source or not. Cause light sources do not shrink. In your case, the sun is a light source, so it will not shrink. The lamp post will also shrink, but the lamp it self not (at least if it is dark and the lamp is switched on).

Lets clarify some things here:
"light sources do not shrink"  Shouldn't the head of the lamp then stay the same size while the post shrinks?

If a lamp on a post is very far away, close to the edge of visibility and the light is off you would hardly see it.  Then the light is turned in and the light unshrinks and appears full size while the post remains small.

This doesn't match the top diagram posted above.  In that diagram the head of the lamp is shrinking as the lamp and post are farther away.
I love this site, it's a fantastic collection of evidence of a spherical earth:
Flight times
Full moon
Horizon eye level drops
Sinking ship effect

Offline hexagon

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #3 on: May 24, 2018, 12:28:20 PM »
Yes, that's would you would expect, but read this:

https://wiki.tfes.org/Magnification_of_the_Sun_at_Sunset#Lamp_Post_Example


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Offline MCToon

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #4 on: May 24, 2018, 02:21:42 PM »
Yes, that's would you would expect, but read this:

https://wiki.tfes.org/Magnification_of_the_Sun_at_Sunset#Lamp_Post_Example

That's just lens flare.  I see the Q/A at the bottom of that page claiming it's a "a projection upon the atmoplane", but lens flaring happens in a vacuum also.  It's a phenomenon of the lens, not the "atmoplane".  This is a well understood aspect of optics.

I see nowhere in EnaG claiming sources of light do not shrink with perspective.  On the contrary, the claim for the setting of the sun relies on perspective shrinking the apparent size of the sun.

To directly address the OP, it seems to me diagram 64 in EnaG simply left off the perspective shrinking of the sun.

I love this site, it's a fantastic collection of evidence of a spherical earth:
Flight times
Full moon
Horizon eye level drops
Sinking ship effect

Offline hexagon

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #5 on: May 24, 2018, 03:52:59 PM »
You're right it's in reality a very simple optical effect, but look at the top of the page I linked. There you find the quotation from EnaG regarding the apparent size of the sun.

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Offline MCToon

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #6 on: May 24, 2018, 04:07:55 PM »
You're right it's in reality a very simple optical effect, but look at the top of the page I linked. There you find the quotation from EnaG regarding the apparent size of the sun.

This quote:
Quote
"IT is well known that when a light of any kind shines through a dense medium it appears larger, or magnified, at a given distance than when it is seen through a lighter medium. This is more remarkable when the medium holds aqueous particles or vapour in solution, as in a damp or foggy atmosphere. Anyone may be satisfied of this by standing within a few yards of an ordinary street lamp, and noticing the size of the flame; on going away to many times the distance, the light upon the atmosphere will appear considerably larger. This phenomenon may be noticed, to a greater or less degree, at all times; but when the air is moist and vapoury it is more intense. It is evident that at sunrise, and at sunset, the sun's light must shine through a greater length of atmospheric air than at mid-day; besides which, the air near the earth is both more dense, and holds more watery particles in solution, than the higher strata through which the sun shines at noonday; and hence the light must be dilated or magnified, as well as modified in colour."

This just illustrated that the author does not have a good understanding of optics.  Denser mediums do not magnify light, the angle of incident between the materials is what causes magnification or contraction.  A convex lens will magnify, a concave lens will contract.  We can confidently discard this quote.


I love this site, it's a fantastic collection of evidence of a spherical earth:
Flight times
Full moon
Horizon eye level drops
Sinking ship effect

Offline SiDawg

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #7 on: May 25, 2018, 12:03:18 AM »
Quote from: https://wiki.tfes.org/Magnification_of_the_Sun_at_Sunset#Lamp_Post_Example
Q: Shouldn't the sun get blurrier if it is being magnified?
A: The sun actually does get a bit fuzzier when it is at the horizon compared to overhead at noonday.

Q: Shouldn't polarized sun glasses or a welding mask be able to restore the sun to its actual state?
A: The explanation is describing a projection upon the atmoplane. The projection is appearing upon a medium between the source and the observer. Polarized sun glasses or welding masks are useful for reducing internal glare lens effects within the eye; but would only darken the scene in this external situation.

It's handy they've provided answers, but they're completely nonsensical. For a start, "a bit fuzzier" is a HUGE stretch from "a tiny point of light somehow becomes the same size disc as it was at noon, with MINIMUM, 1% or less blurring effect".

What is a "projection upon the atmolayer" ?? A projection requires focus on to an image plane. Light through gas is not focusing on anything: light rays are scattering, not converging. It's interesting they give a laser as an example: further proves the RE point. A laser from 1cm shows a single point... a laser diverging at 10m shows a bigger "point", and A LOT fuzzier, when projected on to, say, a wall... there's no "focus" to it at all. It's not as if it's focused for 9cm then fuzzy for the remaining 1cm... it's completely fuzzy.

If you point a laser directly at someone 10m away, they will see the single point in the middle...(or more to the point, they will get a single point burnt in t otheir retina!) they may notice a slight "haze" surrounding it but the majority of the light they see is from the centre point. Try the same with your phone: torn the torch on, hold your phone a meer 5cm from the wall and it projects a pretty huge circle even at that distance: close to 5cm wide on my S8 anyway! Now the hold the phone pointing the torch towards you... 5cm, 10cm, hell even 30cm away from you: do you see a giant 30cm disc of glowing light?? No: you see a very bright spot coming from where the torch is. Their laser light is example is beside the point: obviously the lamps in the photos are illuminate a much larger area than the "orb" of light you can see in the photo, so the laser light example is irrelevant.

Hold your phone in front of your face with welding glasses: because the centre of the light, the light source, is the brightest point, regardless of all the scattering that occurs, the brightest point by far is still the light source. This is where the greatest concentration of light rays, with the greatest intensity, are coming directly towards your eye. The "orb" of light emanating from the torch, is no longer visible, only the light source, and it's true size. Perhaps I need to demonstrate this with photography. It's quite easy to do: just use faster shutter times or smaller apertures.

Perhaps this argument can be won by simply sending flat earthers pairs of welding glasses?

Quote from: Round Eyes
Long range, high altitude, potentially solar powered airplanes [...] If the planes are travelling approx 15 miles about earth, that works out to around 2,200 mph, or Mach 3

Offline hexagon

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Re: Perspective in 'Earth Not a Globe' contradicts itself
« Reply #8 on: May 25, 2018, 09:26:58 AM »


This just illustrated that the author does not have a good understanding of optics.  Denser mediums do not magnify light, the angle of incident between the materials is what causes magnification or contraction.  A convex lens will magnify, a concave lens will contract.  We can confidently discard this quote.

Indeed, it's the shape of the interface between the two media plus the ratio in refractive index that determines the path of the light through the interface. If you have no sharp interface, then the gradient in refractive index and his spacial dispersion determines the behavior of light beams.

By the way, can anyone explain what a "atmolayer" is? Never heard this before...

The best part is the analogy to the laser. The divergence of the freely propagating laser beam is a consequence of the aperture of the laser resonator. You can understand this if you treat the laser beam as a so-called Gaussian beam of zero order. But if you look into the beam, it is imaged by the lens of your eye on your retina and it appears in its original size. Beside, the intensity is too high and you have all glare effects. Just use proper filter and maybe a camera instead of your eye ;-)