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Offline Bobby Shafto

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Observation of Sun Size During the Day
« on: April 23, 2018, 08:15:25 PM »
I thought it would be more appropriate to find an existing topic thread and inject some information into this well-worn topic, but when I tried I received a caution that due to the age and dormancy of the old topic, I might be advised to start a new one. But seeing as this is my first post on this board, I hope I'm not breaking any rules by starting a new topic is a post count of 0.  (I've been posting recently as "Yib" on another flat earth community's forum.)

I've been intrigued by what I would expect the sun to look like as it traversed the sky if the current flat earth visualization was a good model. Like most skeptics of the flat earth model, I feel that I should be able to see a marked difference in the sun's apparent size (width/diameter) from when it is at the highest point of elevation compared to when it is receded into the distance, low in elevation.

There's a video (who's source I can't identify) on YouTube showing a sunset, presumably in the Middle East, that DOES give the appearance I would expect of a diminishing sun as it recedes toward a horizon. But I've never personally seen a sunset like that. By my unmeasured eye, I feel like I see a sun sphere that's basically the same at low altitude as it is at high altitude, and it doesn't diminish to a vanishing point but becomes an obscured circle/sphere, as if over an edge.

So, "is that an illusion?" I ask myself. I've read the wiki(s) that propose a magnification explanation for why the sun doesn't diminish in apparent size as it sets towards the "conversion zone" of the horizon. Yet there are also videos by defenders of the current flat earth model attempting to verify that the sun DOES diminish in size as it "sets" into a vanishing plane/convergence zone.  So, does it or doesn't it?

Yesterday (Sunday, April 22nd 2018) I took some photographs of the sun and tried to be as careful as possible to avoid introducing aspects that would change the angular perspective of the sun. I included a solar filter and exposure settings to reduce the glare of the sun so that I could see its boundary. Using the same focal length for all photographs throughout the day, same resolution, same field of view, and without altering the photographs, it didn't matter whether the sun was at its closest point to my location (San Diego at 69° elevation due south) or 10 minutes to scheduled sunset (1½° elevation to the west). My measurements of the sun's pixel size from every test point was 605px +/- 5 pixels, the variance being due to precision error in where to choose the edge from which to measure.

The consistent size can't be akin to glare or lost focus since I accounted for that. The atmosphere, itself, acts as a filter as the sun's elevation drops and the intensity of the light is diminished. But if that's where magnification due to water vapor begins to take effect, it didn't seem to have a magnifying effect, unless it is perfectly synchronized to maintain a constant angular diameter of the sun until refractive elements take hold at around 1-2°. Only then, at less than 2°, did the circle of the sun start to become distorted, as it got "squashed" and its edge boundaries more irregular. However, it's horizontal width didn't change.

Even with some magnification, I would only expect it to reduce the rate of change, maybe, so that the evening sun might be larger than expected, but nevertheless smaller than the sun at solar noon. But that didn't happen.

I posted this on another forum, but didn't receive any feedback other than from those inclined to already agree with me. I'd appreciate a critical, contrary review. I can either re-post my data and observations, or provide a link to where they are posted.

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Re: Observation of Sun Size During the Day
« Reply #1 on: April 23, 2018, 08:23:19 PM »
Hi Bobby Shafto, I like your post, please can you upload the photos you mentioned as it was add the evidence factor, cheers  :-)

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Re: Observation of Sun Size During the Day
« Reply #2 on: April 23, 2018, 08:52:13 PM »
...please can you upload the photos you mentioned as it was add the evidence factor, cheers  :-)
Might be less cluttering if I just provide links rather than in-lining the images.

Here's a table of the local time of each photograph, sun's elevation at time of photo and my measurement of resulting sun image.
TIME  | EL  | Width
09:25 | 40° | 607px
12:50 | 69° | 603px
15:45 | 45° | 608px
17:10 | 26° | 601px
17:45 | 20° | 610px
18:35 | 09° | 604px
18:55 | 05° | 604px
19:05 | 03° | 600px
19:15 | 1.5°| 601px
19:18 | 0.8°| 609px

And the photos. (These are cropped and annotated, but otherwise unedited. The sun image is unaltered from the original. If anyone needs to see the originals, with the encoded time/date and exposure settings, I can make those available too.)

1. http://oi66.tinypic.com/2ly5suh.jpg
2. http://oi66.tinypic.com/w7bf48.jpg
3. http://oi67.tinypic.com/j9yi2w.jpg
4. http://oi66.tinypic.com/21dk748.jpg
5. http://oi65.tinypic.com/rrl56x.jpg
6. http://oi65.tinypic.com/25tuqna.jpg
7. http://oi68.tinypic.com/2emn8kw.jpg
8. http://oi64.tinypic.com/2195507.jpg
9. http://oi68.tinypic.com/ftzmac.jpg
10. http://oi63.tinypic.com/292tthj.jpg

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Re: Observation of Sun Size During the Day
« Reply #3 on: April 23, 2018, 09:01:31 PM »
The last two show the sun without the use of an E15 solar filter. At that point, the filter was so dimming I couldn't open up the shutter speed/aperture enough to get a picture that I could keep from blurring due to wind moving my tripod.

You can see the slight "bloom" in the unfiltered sun in photo #9 even at a low elevation. That was the best I could do to reduce the glare without the filter.

The focal length for all photos was the same as was the resolution (1920x1080). I've cropped these to 1000x1000 for space, adding a little white space at the bottom for my gauge lines. The pixel widths are preserved.

Again, if there are any optics/camera details needed to evaluate what I've recorded, please ask and I'll do my best to answer. What I'm most interested in any objective flaws in this approach or analysis. I didn't convert these measurements to arcseconds or milliradians, or other common units of angular diameter. I just thought pixel width was sufficient and easiest to gauge.

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Re: Observation of Sun Size During the Day
« Reply #4 on: April 23, 2018, 09:08:30 PM »
I think pixel measurement error is around +/- 5px, which I feel is small enough, and seems to correspond with the upper and lower bounds of what I measured.

Here, you can see the difficulty in choosing a boundary at this resolution, even with the filter. But a 1-2% measuring uncertainty shouldn't obscure any diminution of sun size, if it's occurring.


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Re: Observation of Sun Size During the Day
« Reply #5 on: April 23, 2018, 09:13:49 PM »
Hi Bobby, cheers for the links, having trouble seeing images on my tablet, just takes me to the page but no pics,but will try on my Mac later

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Offline Bobby Shafto

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Re: Observation of Sun Size During the Day
« Reply #6 on: April 23, 2018, 09:19:06 PM »
Hi Bobby, cheers for the links, having trouble seeing images on my tablet, just takes me to the page but no pics,but will try on my Mac later
Hmm. Can you see this (photo #1)


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Re: Observation of Sun Size During the Day
« Reply #7 on: April 23, 2018, 09:52:55 PM »
Yes mate I can see that fine

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Re: Observation of Sun Size During the Day
« Reply #8 on: April 24, 2018, 03:54:23 PM »
No feedback? Criticisms? Commentary?

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Offline Stagiri

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Re: Observation of Sun Size During the Day
« Reply #9 on: April 24, 2018, 04:29:41 PM »
No feedback? Criticisms? Commentary?

FEers often do not respond.
Dr Rowbotham was accurate in his experiments.
How do you know without repeating them?
Because they don't need to be repeated, they were correct.

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Re: Observation of Sun Size During the Day
« Reply #10 on: April 24, 2018, 05:36:15 PM »
I was starting to think it was something about me.

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Re: Observation of Sun Size During the Day
« Reply #11 on: April 24, 2018, 05:41:41 PM »
I was starting to think it was something about me.

Don't worry, it isn't  ;)
Dr Rowbotham was accurate in his experiments.
How do you know without repeating them?
Because they don't need to be repeated, they were correct.

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Re: Observation of Sun Size During the Day
« Reply #12 on: April 24, 2018, 06:47:56 PM »
I was starting to think it was something about me.

Don't worry, it isn't  ;)
I've read Tom Bishop's defense of why lights can appear larger in the distance due to atmospheric effects that counter the usual vanishing point explanation for things getting smaller with distance. But the illustrations he's chosen were streetlights and headlights where focus and optical effects like blooming or glare aren't accounted for.

I feel that by fixing focus, and making filter/exposure adjustments for glare, you can neutralize any blooming and get a sharper edge on the boundaries of the light source.

I could demonstrate how the sun can appear to shrink from a larger intense yellow glow to a smaller, red circle even at solar noon just by applying filtering and adjusting aperture/shutter/ISO. But at a point, the sun stops shrinking (assuming no change to focal length/FOV) and just gets dimmer the more filtering/exposure is applied.

I'm feeling pretty confident that I've captured the boundaries of the sun with my photos to within 1-2%, and that simply measuring pixels is a sound method of comparing diameter of the sun throughout the day as long as the focal point doesn't change. If the sun is moving away from a vantage point on a flat earth along a parallel plane, that pixel width should change markedly in the evening. If there's a magnification effect in play, it's remarkably tuned so that the sun doesn't appear to diminish to a vanishing point but instead remains the same width, even as it appears to sink behind an obstruction.

Not only that, but I can't calculate a way for the sun on a parallel plane 3000 miles above the flat earth to reach a low enough angle to even make it to the apparent horizon.  You run out of room. Given the distances involved, the sun should never appear lower than, say, 20° above the horizon from my vantage point before it would dim and recede. It would require an extraordinary amount of refraction (in the opposite direction) or a lensing medium extending low to the surface to make the sun appear 20° lower than it actually is.

And I can't work out a way for the "spotlight" explanation to be true without it manifesting itself somehow in a way we could see on the shape of the sun at sunrise/sunset. I'm really not trying to provoke anyone to defense of their beliefs or to try to convince anyone to change his mind. I'm just trying to understand how this assembly of explanations fit cohesively into a theory of flat earth and how I can test for them. The size of the sun was just one thing I thought I could examine, and I wanted to see if I could detect a change in sun size as would be predicted by a flat earth sun "setting" into a vanishing point horizon. I don't believe I did detect any change, but maybe there's something I missed or a flaw in my method or assumptions. I don't know any flat earthers to ask personally, so I came here (after finding no real FE input on the other community's message board).
« Last Edit: April 25, 2018, 03:18:22 PM by Bobby Shafto »

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Re: Observation of Sun Size During the Day
« Reply #13 on: April 29, 2018, 05:49:13 AM »
Noticed the moon tonight at sunset. Thought I'd take the opportunity to "measure" it's width too. Same camera, focal length and resolution.



If I get up in time, I'll check and add the setting moon in the AM.

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Re: Observation of Sun Size During the Day
« Reply #14 on: April 29, 2018, 05:55:13 AM »
Just a comment:
The moon was coming up over a low ridge when I took that first shot about 25 minutes before sunset. It looked huge. When I took the later shot when the moon was higher and the sky dark, it looked "normal."

I'd always heard the apparent large moon on a horizon of trees, or houses, or mountains was an optical illusion, due to the context of the terrestrial or man-made features. Still, I was surprised to see that, at least by measuring pixel width, the two moon images were the same size.




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Re: Observation of Sun Size During the Day
« Reply #15 on: April 30, 2018, 07:49:46 PM »

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Re: Observation of Sun Size During the Day
« Reply #16 on: April 30, 2018, 08:43:43 PM »


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Re: Observation of Sun Size During the Day
« Reply #18 on: May 01, 2018, 08:23:19 PM »
I know which version I've seen, the only empirically observed option. The idea that sunset is "perspective" at work is utter b****x as this image shows

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Re: Observation of Sun Size During the Day
« Reply #19 on: May 02, 2018, 07:14:55 AM »
Taken from a video in which the videographer/narrator claims this is of the sun "shrinking" into the convergence layer.



Where he believes he sees a shrinking sun at the horizon intersection, I see the upper arc of a sun's disc, for which the diameter never changes.