[Sup3rbuck]

Hello. 

I've tried to find this experiment but I've been unsuccessful.
Have this been done or is underway?

A balloon is up in the atmosphere when the sun is direct opposite on the "globe".
Should it not then be possible to see the sunrise or sunset feature in the horizon?
As the sun never descents below the horizon on the FE.

Thank you
/k

[Disgraced_Shield]

I'm a little confused by the post- maybe it's in the wording.

You're asking if you're high enough up in he atmosphere, if you're able to see a sunrise/sunset as a FE model does not allow for a horizon for the sun to sink behind?

[Sup3rbuck]

Thank you.
That's exactly what i mean.

Even if the law of perspective wouldn't allow me to see the sun directly it should
Show a sunrise/sunset ?

[Pongo]

You cannot see the sun when it's on the opposite side of the disk because air is not transparent.  Over a distance the light from the sun diffuses.

[Disgraced_Shield]

You cannot see the sun when it's on the opposite side of the disk because air is not transparent.  Over a distance the light from the sun diffuses.

Erm......

Not really.

I mean yeah, but you're talking about some significant distances here. The human eye is capable of seeing a single candle flame 1.7 miles away. (And this is one of the more conservative estimates I've found from searching)

http://www.technologyreview.com/view/539826/how-far-can-the-human-eye-see-a-candle-flame/

Even if- as proposed by some- the sun were 32 miles in diameter, the exponential increase in the distance from where this could be viewed from above negates the possibility that the sun would not be visible from altitude.

Say a single candle flame is 1" in diameter.  and we use the estimations in the above link, then round DOWN from 1.7 miles to 1.5 so we're dealing with round numbers.

Pretend that the sun is 32 miles in diameter.

Supposing:

at 1" in diameter, flame is visible at 1.5 miles.
at 1' in diameter, a flame is visible at 18 miles.
at 1 MILE in diameter, flame is visible at 95,040 miles.
at 32 miles in diameter (oft proposed size of sun)..... 3,041,280 mile visibility.

Again, this is using a conservative estimate, and rounding down from 1.7 to 1.5 for the sake of simplicity. AND assuming that the sun wouldn't be any brighter at the base measurement than a candle flame.

There's no way that you'd not be able to see the sun from any less than 3 million miles away.

***Now, all of this hinges on my candle flame being 1" in diameter. Granted, that's a big flame and an arbitrary number chosen for simplicity.  Shrink the size of the candle flame down to something more realistic, and the numbers go up. With a 1/8" candle flame, you're talking about 5.8 million miles of visibility at 32 miles in diameter of the light source.


Given this- let us now play with the conventionally accepted size and distance measurements of the sun.
at 864,948 miles in diameter, and 92 million miles away, the ONLY way that we would be unable to see it is if it is on the other side of where we happen to be standing, ie: on the other side of a globe.
And, since nighttime actually happens, this can be the only explanation.

[Charming Anarchist]

You cannot see the sun when it's on the opposite side of the disk because air is not transparent.  Over a distance the light from the sun diffuses.

Erm......
Not really.

Erm.... 
Yes really. 

I mean yeah, but you're talking about some significant distances here.

No, your are NOT talking about any significant distances required to obfuscate the sun. 

The human eye is capable of seeing a single ....

.... cloud TOTALLY block the light of the sun.  That is all men need for proof. 
Unless you are blind or locked inside, you have seen the shadow of a cloud on the ground.  You have looked up in the sky to see a cloud block the blinding rays of the sun. 

Add a 2nd cloud behind the 1st cloud and then a 3rd cloud behind the 2nd cloud and so on and so on and so on until it is clearly night time. 

Night is dark because the sun's rays can not penetrate layers of clouds.  A few floating particles and or vapor over long distances eventually blocks the sun. 

[Disgraced_Shield]

Ah. Of course. Clouds. Because there's never any time or place when cloud cover is scant or lacking. Not only that, but I forgot that it's impossible to tell the difference between 'day' and 'night' on an overcast day, because clearly, cloud cover is impenetrable.

Take a completely dark room. Stick a 4x8 sheet of plywood and a single 60 watt bulb on one side of it. Stand on the other side of the board. See the light?

You're grasping at straws.

[Tellthetruth]

As I am still so new at this subject, I may have missed something.
But is it not possible that the sun could be outside the firmament?
(Cold fusion or not) (3000 mi. diameter or not)
That would answer some questions on my new found "Faith"
As the Sun could move around our earth (Even a flat earth) and answer may observable questions.
I can't help even thinking the "Firmament could have magnifying properties (Or vice versa).

[Charming Anarchist]

You're grasping at straws.

No, I am not. 

If the earth was a globe with an atmosphere, the "parallel" rays of the sun would wrap around the globe.  There would never be any night time.   That is obviously not the case because the earth is not a globe. 

[andruszkow]

You're grasping at straws.

No, I am not. 

If the earth was a globe with an atmosphere, the "parallel" rays of the sun would wrap around the globe.  There would never be any night time.   That is obviously not the case because the earth is not a globe.

... What? Rays of lighting, wrapping around something? Wait, what?

[Disgraced_Shield]

Also, you're forgetting that we're talking about weather balloons, or other high-altitude experimentation and observation...which most likely is above a good portion of cloud cover. You know, as is the sun.

You're literally asserting that if a light source if obstructed, light can't be seen, which is ludicrous.

But, lets play math again, using the measurements I made from before, which are more than fair.

We're talking about a light source which is visible at over three million miles (again, conservative estimate) when unobstructed. Now lets throw in substantial cloud cover.
I'm not sure what the proposed diameter of the flat earth is, the circumference of the globe is roughly 25,000 miles.

Let's pretend that the diameter of the flat earth is I dunno....four times that, and it's 100,000 miles from one end to the other. Let us now pretend that the sun in your model is sitting exactly on one extreme point of the disk, and I'm in a balloon on exactly the other side. I'm at a point where my ability to view the unobstructed sun has been diminished by a mere 3.33% Cloud coverage across the earth would need to obstruct 97% of the rest of the light.

If the disk is any smaller than 100,000 miles, or the sun and I are NOT on exact extremes of the disk when observed, you're talking about a fairly significant amount of cloud coverage to block out 99%+ of sunlight.

....IF the earth is flat, and IF you're conducting the visual experiment from a low enough altitude that you're not above any cloud coverage.

Oh, and remember we're still using a conservative estimate for visual light observation, a rather large 1" wide flame as a starting point for our numbers, and rounding down from 1.7 miles for the visibility of said flame to 1.5 for the sake of simplicity. I'm giving a LOT of wiggle room here all of it in your favor, and the numbers still don't line up to support your claim.

[Disgraced_Shield]

You're grasping at straws.

No, I am not. 

If the earth was a globe with an atmosphere, the "parallel" rays of the sun would wrap around the globe.  There would never be any night time.   That is obviously not the case because the earth is not a globe.

Ah, yes. Poisson's spot. The experiment which says that the light source needs to be a laser beam or a pin-hole light and the surface of the sphere needs to be perfectly smooth in order for it to work.
Not...you know...a star...illuminating a spheroid with geographic landforms, and shifting seas.

Much the same way as the cosmic ray device holding up satellites and clouds argument, this is another proof of concept experiment done in a lab under very specific conditions. You're discarding those conditions to fit your own ends.

The experiment says a focused light on a perfectly smooth sphere.
You read it as 'light on round thing' ignoring the specifics that grant the experiment its legitimacy. 

...and this is ignoring the fact that the entire experiment has got to fit Fresnel's criteria. Which I'll admit is above my head, but in short says that the diameter, distance, and wavelength of light source have to be perfect in order for it to work. A pretty tall order for the cosmos to meet by chance no?