We live on a globe, not a flat earth. This post was requested in another thread but got buried there.

Regarding the Christianized flat earth nonsense, it seems to me that the wrong questions are being asked.

Christians often summon the following two verses (and a great many more) in support of their flat earth claims:

"And he shall set up an ensign for the nations, and shall assemble the outcasts of Israel, and gather together the dispersed of Judah FROM THE FOUR CORNERS OF THE EARTH."

- Isaiah 11:12 KJB

"It is he that sitteth UPON THE CIRCLE OF THE EARTH, and the inhabitants thereof are as grasshoppers; that stretcheth out the heavens as a curtain, and spreadeth them out as a tent to dwell in."

- Isaiah 40:22 KJB

The Biblical argument for a flat earth is allegedly based on a literal and geometrically sound interpretation of the phrases "from the four corners of the earth" and "upon the circle of the earth."

Well, let's call that bluff.

Rather than ask, "Do the relevant Scriptures support the idea of a flat circular earth lying in a plane having four corners?", ask instead, "Can the relevant Scriptures survive the idea of a wholly spherical earth fixed in an orbit through empty space?"

Let us assume that the earth is indeed spherical - a globe!

According to the rules of geometry, a two-dimensional (flat) circle in two-dimensional space can be completely rotated about its diameter "into" our three-dimensional space as a sphere. In addition that finished sphere requires at a minimum 4 conditionally selected non-coplanar surface points to completely and uniquely define it as such.

Those 4 conditionally selected non-coplanar surface points ARE the four corners of a globe-shaped earth.

Therefore, Isaiah 11:12 survived the idea of a wholly spherical earth within the limits of reason.

Next, Isaiah 40:22 talks about the circle of the earth. Note that it does NOT say the CIRCULAR earth but rather the circle OF the earth; that is, a circle unique TO the earth.

Here is where the burden of proof falls apart for the flat earthers.

Flat earthers often use the results obtained from their application of geometry and trigonometry to publish their data, or "proof" as they like to call it. The problem is that there are two types of geometry and trigonometry we need to understand for the sake of this discussion: linear geometry and linear trigonometry for general two-dimensional planar surfaces; and spherical geometry and spherical trigonometry for highly specific three-dimensional spherical surfaces such as a globe.

Linear geometry and linear trigonometry have no place in the analysis of spherical surfaces except locally. That is to say, you can use that kind of analysis in a measurement environment close to where you are physically, but outside that locality precise measurements are impossible.

In linear geometry/trigonometry we have "parallel lines that do not intersect". In spherical geometry and trigonometry we don't have lines. Instead we have what are called "great circles (yup, that's what they're called) where the curves of those circles intersect at the opposing poles of the sphere".

You've all seen pictures of a new bridge which had started out being built from both sides of the bank over a wide water source and at the same time. Where the pieces of the bridge were to meet and fit together in the middle, instead they were so far off the mark and produced such a wide gap that one side had to be completely rebuilt. This engineering fiasco was due to the engineers' failure to account for the curvature of the spherical earth. Their initial measurements only used the results obtained from linear analysis. What an embarrassment. Fortunately such incidents are rare but you still won't find world-class engineers on social media networks like YouTube busily correcting misguided flat earthers. That means all analysis is self-moderated by the YouTube collective and therein lies the problem.

If you want to take measurements of a spherical earth, you need to apply spherical geometry and spherical trigonometry. If the flat earthers did that, they would soon see their prized flat earth theories fly out the window,

Now that I've said that, what is the one single highly visible great circle of the earth that can be viewed partially from the air or wholly from outer space?

That great circle, the Biblical circle of the earth, is the "earth's terminator", also called the gray line or twilight zone. It is the visible line around the earth that separates hemispheric day from night.

"I create the light, and create darkness: I make peace and create evil: I the LORD do all these things."

- Isaiah 45:7 KJB

Well...isn't that the same glorious LORD that sitteth upon the circle of the earth, the terminator which separates light from darkness which he himself created and wants us to know about (Isaiah 40:22 KJV)?

Therefore, Isaiah 40:22 has also survived the idea of a wholly spherical earth within the limits of reason.

I might also add that in our three dimensional world a circle can exist on a sphere (IE, the terminator) but it cannot exist outside of a sphere (IE, all by itself). Not in our 3D world! So if the flat earthers were to remain true to their literal flat earth shaped like a literal circle theory, they would need to explain why such a flat circular earth has...well...thickness, which makes it a disk and not a circle.

Geometry 101.

I could say more (like the myths about how accurate lasers are when used in measurement, etc) but not in this post.

Suffice is to conclude that Scripture does not favor a flat earth interpretation.