Moon Tilt Illusion

Description
Professor Myers at the University of Pennsylvania provides the following description:

http://www.upenn.edu/emeritus/essays/MyersMoon.html (Archive)





Sun and Moon Anomaly
From a Stack Exchange post on the Moon Tilt Illusion we read:





A Different Moon Illusion
Another observation is given here:

http://www.astropix.com/html/l_story/moonill.html (Archive)



Perspective Explanations
An explanation of the Moon Tilt Illusion is given in the form of a perspective effect. It is possible to get very close to an object and make it appear to change angle and point upwards, downwards, or to the side. It is claimed that this is occurring with the Moon.

A VSauce video titled The Moon Terminator Illusion (Runtime:11m) explains the Moon Tilt Illusion via a perspective effect:



In the above demonstration VSauce references a close range perspective effect. However, that same effect is not going to occur with the same motions of the camera if the screen is far from the observer. The camera would need to move of equal proportions if the laptop screen is far away. Under the Sun-Earth-Moon system the bodies maintain the same distances from the observer at all times, and do not move closer or further from the observer enough, as compared to their distances, as to cause a large perspective effect changes.

Another version of the perspective argument is given here:



The Moon is pointing downward at the Sun at the horizon. Moving the camera close to the Moon, the Moon appears to point upwards.

In contrast to this argument, under the Round Earth Theory both the Sun and the Moon are far away from the observer and are at equal distance from the observer at all times. They do not change distances radically from the observer, as the camera changes in relation to the Moon in the above animation. As an example; a pencil 10,000 feet away from the observer will not be subject to close range perspective as easily as a pencil held an arms length away. Hence, the explanations are extraneous to the systems in the Round Earth Theory.

According to the Round Earth Theory over the course of a day the changing of distance to the Moon over the course is negligible. The Moon maintains its distance from the center of the Earth at all times slowly rotating around it. The Earth in turn rotates at a faster rate in relation to the Moon. An observer on the surface of the Earth at the Equator will observe a change in the position of the Moon by less than 2 degrees, as demonstrated in the below illustration:



The argument that perspective can cause drastic changes to the positioning of the Moon is questionable. The argument given with toys at close range is of little relation to the systems proposed by astronomy. A geometric explanation applicable to such a scheme is unavailable.

Celestial Sphere
Another explanation given involves a "Celestial Sphere" in the sky, upon which straight lines become curved.

In the paper The Moon Tilt Illusion by Adrea and Alan Myers, the following is stated:

We are told that straight lines become curved when looking into the sky because of the "celestial sphere" which exists above our heads.

A demonstration against this concept may be found in any 3D modeling program. Create a long straight line and place the camera at various distances from it. At what point does the straight line become curved? The answer we have found is: At no point. A straight line in the distance will always be straight. Hence, the concept of a celestial sphere is shown to be an artificial concept bearing no relation to the 3D space which the Sun-Earth-Moon systems of astronomy are said to exist in.