If you want to prove that the moon is a disk, here is how you do it. Have one person north of the equator, say in Canada, and one person south of the equator, say in Argentina, take a picture of the moon at the same time. Then compare the two images, rotate it, adjust the size, and see if it shows the same surface area of the moon. If the moon is a disk, then you will see the same surface area. If it on the other hand is a ball, one side should be able to view a surface areas that the other side is not able to view.
To demonstrate this principal, you could set up stripped ball, and have two people stand 100 meters away from it, and 3 meters apart from each other, then have them use superzoom camera to take a picture of the stripped ball. They will not take a picture of the same surface area of the stripped ball. If you on the other hand do this with a disk, they will take a picture of the same surface area of the disk.
if the moon was a disc then looking at it from any angle besides head-on would result in it looking oval shaped
It depends on how far away it is and how far you move in relation to that distance. If the moon is very far away (as is believed) and your motion on the earth is relatively very small - then it is very unlikely you will be able to detect any such minuscule shape deformation (especially with your eyes). In much the same way as the sun changes size as it increases and decreases distance from us - it is very difficult to detect for the same reason(s).
But there's only one shape that appears as a perfect circle no matter what angle it's viewed from, and that's a sphere.
Of course not, but if your vantage to it is limited - it certainly can, and can even be perceived to be convex when it is not. That was my only, admittedly minor, point.
If you want to prove that the moon is a disk, here is how you do it. Have one person north of the equator, say in Canada, and one person south of the equator, say in Argentina, take a picture of the moon at the same time. Then compare the two images, rotate it, adjust the size, and see if it shows the same surface area of the moon. If the moon is a disk, then you will see the same surface area. If it on the other hand is a ball, one side should be able to view a surface areas that the other side is not able to view.
To demonstrate this principal, you could set up stripped ball, and have two people stand 100 meters away from it, and 3 meters apart from each other, then have them use superzoom camera to take a picture of the stripped ball. They will not take a picture of the same surface area of the stripped ball. If you on the other hand do this with a disk, they will take a picture of the same surface area of the disk.
It depends on how far away it is and how far you move in relation to that distance. If the moon is very far away (as is believed) and your motion on the earth is relatively very small - then it is very unlikely you will be able to detect any such minuscule shape deformation (especially with your eyes). In much the same way as the sun changes size as it increases and decreases distance from us - it is very difficult to detect for the same reason(s).
It could be concave as well.
Concave wouldn't look like a perfect circle from every angle
Of course not, but if your vantage to it is limited - it certainly can, and can even be perceived to be convex when it is not. That was my only, admittedly minor, point.
Could be, have not considered that. Guess I need to look more into how the moon is plasma, and how plasma works.
I already know the moon is a sphere because I saw it through a telescope.