[Tom Bishop]

globe earth has a simple answer for how one location can see the sun angle southward during sunset and another location see the sun angle northward.
If this can be resolved on a flat earth, I haven't figured out how or seen anyone else do so.

The sun is south of you when you are north of it and north of your when you are south of it. Any perspective angle it sets at will be reversed.

Imagine an unrealistically strong baseball player throwing a baseball straight into his horizon. Being directly under the ball he sees it follow a straight path and fall straight down into the horizon.

To someone 200 feet to the left of him, looking into the distance, sees the ball come out from the right side of his view point, which drifts leftward, centered to his vanishing point, since perspective attempts to combine all receding bodies to a point in front of the observer.

To someone 200 to the right of the observer, vice versa.

That this is related to latitude number in any way is only because the latitudes were originally defined that way.

[Bobby Shafto]

That this is related to latitude number in any way is only because the latitudes were originally defined that way.

Is the bath of the baseball (line of latitude) straight? Or does it turn left or right?

[JCM]

globe earth has a simple answer for how one location can see the sun angle southward during sunset and another location see the sun angle northward.
If this can be resolved on a flat earth, I haven't figured out how or seen anyone else do so.

The sun is south of you when you are north of it and north of your when you are south of it. Any perspective angle it sets at will be reversed.

Imagine an unrealistically strong baseball player throwing a baseball straight into his horizon. Being directly under the ball he sees it follow a straight path and fall straight down into the horizon.

To someone 200 feet to the left of him, looking into the distance, sees the ball come out from the right side of his view point, which drifts leftward, centered to his vanishing point, since perspective attempts to combine all receding bodies to a point in front of the observer.

To someone 200 to the right of the observer, vice versa.

That this is related to latitude number in any way is only because the latitudes were originally defined that way.

That is dodging the question. Latitude were not created to explain anything. They are the result of being a sphere, they work perfectly because we are...  a sphere. 

The sun is setting in a different direction.  On a FE map when the sun is setting it is never doing what is clearly seen in Perth.  Explain at setting the sun's movement please on a flat earth model.

[QED]

"To someone 200 feet to the left of him, looking into the distance, sees the ball come out from the right side of his view point, which drifts leftward, centered to his vanishing point, since perspective attempts to combine all receding bodies to a point in front of the observer."

I think it would only drift leftward if the Earth was curved. On a FE, it should continue straight and keep the same azimuthal angle relative to the left-positioned person. Right?

Also, I am confused about your terminology of "vanishing point." The reason why I am confused is that we do not observe a vanishing point, we observe a vanishing axis. Objects which disappear below the horizon do so along a curved axis, but not at the same location on that axis. This is easily demonstrated by watching two ships "vanish." They vanish from sight at different locations.

[Bobby Shafto]

I think it would only drift leftward if the Earth was curved. On a FE, it should continue straight and keep the same azimuthal angle relative to the left-positioned person. Right?

No, I think he's right. If earth is a flat plane and you are south of the sun's transit, as the sun loses elevation (somehow) it will also experience southerly or CCW bearing drift (albeit at a decelerating rate which would make the slope of that angled descent curved).

The problem for that explanation on flat earth is that the sun's path over the earth, like the thrown baseball, is straight for that to work. But on every flat earth depiction I've seen so far, the sun's path is circular. Only on the proposed bi-polar map is the sun's path temporarily straight-ish, and then only near the equinoxes. As I said before, to work on a flat map, the sun's path must be continuous somehow and essentially a straight path along a line of latitude that doesn't curve. How do you do that on a flat surface without a GOTO command transporting the sun from west back to east like a space warp?  As soon as you have to bend lines of latitude into circular or elliptical shapes, you defy this observable  behavior of the sun. You'll need bending, reflecting or trickery of light to explain it. I can come up with no geometry that will solve the puzzle except for a globe.

[AATW]

Hmm. This is making my head hurt a bit but I think this is the flat earth situation:



So the sun is going round in a circle above the plane of the earth. If you're at A then you'd see it from one side, if you're at B then you'd see it from the other.
If the sun is going down at an angle, left to right in the top image then if you're at A you'll see it at a different angle to B.
I'm not convinced you'd see it going in completely the opposite direction though - right to left instead of left to right.

 

[Curious Squirrel]

I think you've got it right, at least as I understand it AAtW. An important bit to note here, is IF this is correct, you don't have your ball thrower location in Tom's example above. There IS no location where the sun visibly sets straight down, without light bending in the horizontal direction. Is that what we've got for FE to explain this? Just 'magic'?

[Tom Bishop]

I address the curve of the sun's path as follows:

Imagine an unrealistically strong baseball player throwing a baseball straight into his horizon. Being directly under the ball he sees it follow a straight path and fall straight down into the horizon.

To someone 200 feet to the left of him, looking into the distance, sees the ball come out from the right side of his view point, which drifts leftward, centered to his vanishing point, since perspective attempts to combine all receding bodies to a point in front of the observer.

To someone 200 to the right of the observer, vice versa.

That this is related to latitude number in any way is only because the latitudes were originally defined that way.

Now consider the following:

If it is a windy day and the baseball is being pushed to the right, as it travels through the air and descends into the horizon, would the person 200 feet to the left of the baseball player still see the baseball come in from the right side of his viewpoint and attempt go to center?

Of course he would. Perspective attempts to bring all things to the observer's center.

[Curious Squirrel]

I address the curve of the sun's path as follows:

Imagine an unrealistically strong baseball player throwing a baseball straight into his horizon. Being directly under the ball he sees it follow a straight path and fall straight down into the horizon.

To someone 200 feet to the left of him, looking into the distance, sees the ball come out from the right side of his view point, which drifts leftward, centered to his vanishing point, since perspective attempts to combine all receding bodies to a point in front of the observer.

To someone 200 to the right of the observer, vice versa.

That this is related to latitude number in any way is only because the latitudes were originally defined that way.

Now consider the following:

If it is a windy day and the baseball is being pushed to the right, as it travels through the air and descends into the horizon, would the person 200 feet to the left of the baseball player still see the baseball come in from the right side of his viewpoint and attempt go to center?

Of course he would. Perspective attempts to bring all things to the observer's center.

'Magic' is all I'm hearing here. But let me make sure I'm understanding this correctly.

If we place an observer on A, B, and C in the following image, with our powerful thrower at B. He throws a ball 3 times, each time it follows a different path X, Y, and Z. According to you, none of these 3 observers will be able to tell the difference between each of these throws?


If that is incorrect, please try and correct me. If that is correct, what evidence do you have to support this hypothesis?

[Tom Bishop]

In your illustration the horizontal difference of the end point between X and Y is a small difference far out in the distance to the observer, and only occupies a small amount of space, due to perspective. The same applies for the distance between Y and Z.

Not to say that the difference between the two would be "exact" with all variables, but we are not talking about anything "exact" here, only an explanation for why the directions would flip with the position of the observer.

[Bobby Shafto]

If it is a windy day and the baseball is being pushed to the right, as it travels through the air and descends into the horizon, would the person 200 feet to the left of the baseball player still see the baseball come in from the right side of his viewpoint and attempt go to center?

Of course he would.

Of course he would what? Come in from the right or attempt to go to center?

Apply your analogy to the most common flat earth sun motion, with the "wind" pushing the sun to the right from the perspective of Perth. This is an old graphic I made, but it happens to include Perth:
 


Which way should the bearing line drift as the sun approaches the horizon as seen from Perth on this flat earth?
A. "In from the right" away from "center"; or,
B.  To the right toward "center?"

Looks like B to me. Is that what you mean when you say "of course would?" And yet, in Perth, the sun's bearing drifts left.

Perspective attempts to bring all things to the observer's center.

But they're diverging away from center. From Perth's perspective, the sun is angling southward. From Hong Kong's perspective, it's angling northward.

[Tom Bishop]

That video was published on Feb 14, 2015, which is when it is summer for the Southern Hemiplane. The sun is traveling around the South Pole at that time. Looking Westwards, not only is the sun left of the equator, the sun is also curving around the South Pole.

[stack]

That video was published on Feb 14, 2015, which is when it is summer for the Southern Hemiplane. The sun is traveling around the South Pole at that time. Looking Westwards, not only is the sun left of the equator, the sun is also curving around the South Pole.

Are you referring to the FE bi-pole sun 'figure 8' model? If so, where exactly was the sun on Feb 14, 2015 in this model?

[Bobby Shafto]

That video was published on Feb 14, 2015, which is when it is summer for the Southern Hemiplane. The sun is traveling around the South Pole at that time. Looking Westwards, not only is the sun left of the equator, the sun is also curving around the South Pole.

You're basing that on a bi-polar flat earth model. Fine. Let's check that.

Then during Perth's winter, when the sun is circling the North Pole, the sun should set in a right-ward or northerly angle. Does it?
And during Perth's summer, when the sun is circling the South Pole, the sun should set in a left-ward or southerly angle as seen from Hong Kong. Does it?
 
They should be the same.

You're a fan of analogies. Here's one. If the sun is following a racetrack pattern, then let's imagine one observer in the grandstand outside the oval and one on the inner track inside the oval.



As each follows the racers around the track, the grandstand viewer swivels left and right to watch. The inner track viewer has to rotate around to follow the race. Along the western bend, both viewers will be seeing the racers go right. The grandstand viewer won't be seeing the racers go left while the inner track viewer sees them go right.

Flip the track over onto the grandstand viewer so that he is now inside the oval and the other one is now in the grandstand. The situation is changed, but they both would agree on the bearing drift of the racers around that bend.

The challenge is to work out a way for them to watch the racers and see opposite drift. What would that track look like?

[Curious Squirrel]

In your illustration the horizontal difference of the end point between X and Y is a small difference far out in the distance to the observer, and only occupies a small amount of space, due to perspective. The same applies for the distance between Y and Z.

Not to say that the difference between the two would be "exact" with all variables, but we are not talking about anything "exact" here, only an explanation for why the directions would flip with the position of the observer.

What a delightful non-answer, that also provides zero evidence to support your statement. Yes/no the situation described using my image is what you are stating is true. I'm not interested in how accurate/inaccurate the distances are after perspective is factored in (we're talking about distances that will be significant when we're speaking of the sun though I would note). If yes, what is your evidence for claiming there would be no difference between each throw? Because I'm pretty sure if we place two ships at the horizon and put them 200 feet apart you could tell the difference between each ship at that point. So from where do you draw your evidence that the sun would be different when it also involves greater distances left/right as well.

[Tom Bishop]

In your illustration the horizontal difference of the end point between X and Y is a small difference far out in the distance to the observer, and only occupies a small amount of space, due to perspective. The same applies for the distance between Y and Z.

Not to say that the difference between the two would be "exact" with all variables, but we are not talking about anything "exact" here, only an explanation for why the directions would flip with the position of the observer.

What a delightful non-answer, that also provides zero evidence to support your statement.

You need evidence that things are smaller in the distance?

Yes/no the situation described using my image is what you are stating is true.

Yes, it apples to your image.

 

If yes, what is your evidence for claiming there would be no difference between each throw?

I didn't say that there would be no difference at all. I said that the observer to the left of the baseball player would see the ball coming in from the right of his view, traveling leftwards towards his center, despite that wind is blowing the baseball to the right during the throw.

To that observer there may be a difference of landing point and specific angle, when comparing with and without the wind, sure.

[stack]

That video was published on Feb 14, 2015, which is when it is summer for the Southern Hemiplane. The sun is traveling around the South Pole at that time. Looking Westwards, not only is the sun left of the equator, the sun is also curving around the South Pole.

If the sun is curving around the south pole, from this shot on 2/17/2015, I would expect a decidedly southern sunset from this vantage point in Liverpool. Where is the sun in the model you present on this day?

[Bobby Shafto]

Are you referring to the FE bi-pole sun 'figure 8' model? If so, where exactly was the sun on Feb 14, 2015 in this model?

At sunset on Feb 14th 2015 in Fremantle, the sun was over Angola. It had set just less than a hour before in Hong Kong.

And I see you added Liverpool. Sunset for Liverpool that day, the sun was on the western edge of Peru, about go "feet wet" over the Pacific.

Out of curiosity, and for Tom, I plotted those positions on the bi-polar flat earth map. And it appears to me that though the bearing lines are off in cases, the sunset bearing drift angle WOULD appear to be solved for all 3 spots.



Besides the bearings being off, solving for this particular "angle of descent" puzzle on this day invokes problems for solving other such puzzles. I'll leave it to Tom to decide if he thinks this model answers solves the puzzle or if he can identify what's still wrong.

But yeah, for Hong Kong and Perth, this model, on this day, would answer why the sun descends at the angle observed, with the bearing drift observed.

[Bobby Shafto]

If the sun is curving around the south pole, from this shot on 2/17/2015, I would expect a decidedly southern sunset from this vantage point in Liverpool. Where is the sun in the model you present on this day?

The observed Liverpool sunset on 2/14/2015 was on an azimuth of 249° (and it's bearing drift was northerly).
Based on the bi-polar map, a direct line from Liverpool to the sun's location would have a bearing of about 225° (though the bearing shift would still have been northerly as observed, just at a different rate/angle).



Without regard to the steepness of the angle (aka rate of bearing drift), that would appear the bi-polar projection solves the puzzle I presented. Hoping Tom will identify where it fails.

[QED]

I think it would only drift leftward if the Earth was curved. On a FE, it should continue straight and keep the same azimuthal angle relative to the left-positioned person. Right?

No, I think he's right. If earth is a flat plane and you are south of the sun's transit, as the sun loses elevation (somehow) it will also experience southerly or CCW bearing drift (albeit at a decelerating rate which would make the slope of that angled descent curved).

The problem for that explanation on flat earth is that the sun's path over the earth, like the thrown baseball, is straight for that to work. But on every flat earth depiction I've seen so far, the sun's path is circular. Only on the proposed bi-polar map is the sun's path temporarily straight-ish, and then only near the equinoxes. As I said before, to work on a flat map, the sun's path must be continuous somehow and essentially a straight path along a line of latitude that doesn't curve. How do you do that on a flat surface without a GOTO command transporting the sun from west back to east like a space warp?  As soon as you have to bend lines of latitude into circular or elliptical shapes, you defy this observable  behavior of the sun. You'll need bending, reflecting or trickery of light to explain it. I can come up with no geometry that will solve the puzzle except for a globe.

That makes no sense to me: "as the sun loses elevation (somehow) it will also experience southerly or CCW bearing drift (albeit at a decelerating rate which would make the slope of that angled descent curved)."

What causes this drift?

If the Sun's trajectory curves, then its acceleration is non-zero. If that is the case, then there is a force causing this acceleration. In my rest frame, there is no force operative. So I do believe you are mistaken: A setting Sun bound southward in the FE model should continue its decent in a straight path relative to you, and cross the horizon south of me.

Things don't just "drift" unless they are rotating relative to each other.