Question: How did ancient people of the Old and New Worlds view the "the world"?

Ancient people conceived of the world on a much smaller scale than we do today. For them, "the world" consisted of the lands and nations they were aware of in their immediate area

The way that ancient people viewed "the world" has critical implications for how we read ancient scripture.

Ancient people conceived of the world on a much smaller scale than we do today. For them, "the world" consisted of the lands and nations they were aware of in their immediate area. They didn't understand "the earth" to be an enormous sphere; rather, they visualized it as a comparatively small, flat disk. (When you look to the horizon, that's an obvious conclusion to make.)

In Exodus 10:15 we read that the Lord sent a swarm of locusts that "covered the face of the whole earth"

This view of the world appears throughout the Bible:

In Exodus 10:15 we read that the Lord sent a swarm of locusts that "covered the face of the whole earth." Obviously, this couldn't mean that locusts covered all the land on the entire planet earth! To the author of Exodus, "the whole earth" meant "all the land we can see." Similarly, according to Genesis 41:56, in the days of Joseph there was a famine that "was over all the face of the earth." This passage is not suggesting there was a global famine, but a famine that affected Egypt, Palestine, and all the other lands in the Near East. Neal has already mentioned Luke 2:1's description of "a decree from Caesar Augustus, that all the world should be taxed." Naturally, "all the world" refers to the limits of the Roman Empire, and wasn't meant to include Scandinavia, southern Africa, east Asia, or the American continent. Acts 2:5 tells us that devout Jews "out of every nation under heaven" had come to Jerusalem to observe the feast of Pentecost. Are we assume this means that "every nation under heaven" included the western hemisphere, where the descendants of Lehi still kept the Law of Moses? Of course not.

Regarding the Flood of Noah, the Genesis account tells us that "the waters were on the face of the whole earth"

Regarding the Flood of Noah, the Genesis account tells us that "the waters were on the face of the whole earth" (Genesis 8:9) and "all flesh died that moved upon the earth" (7:21).

Alma in the Book of Mormon: "his voice was as thunder, and it shook the whole earth"

As an ancient document, the Book of Mormon employs the same usage of the phrases "the whole earth" and "the whole world":

Alma₂ testified that the angel who appeared to him and the sons of Mosiah₂ "spake unto us, as it were the voice of thunder, and the whole earth did tremble beneath our feet" (Alma 36:7), and "his voice was as thunder, and it shook the whole earth" (Alma 38:7). Surely the entire planet wasn't trembling at the sound of the angel's voice; rather, all the ground in the area around the five men shook.

After the great Nephite-Lamanite War, the Book of Mormon peoples "did multiply and spread, and did go forth from the land southward to the land northward, and did spread insomuch that they began to cover the face of the whole earth, from the sea south to the sea north, from the sea west to the sea east" (Helaman 3:8). Notice how "the face of the whole earth" meant, for Mormon₂ (the editor), the entire lands the Nephites and Lamanites possessed (which were small enough to be traversed in a period of a few weeks). Nephi₂ called down a great famine, and we are told that "the whole earth was smitten, even among the Lamanites as well as among the Nephites" (Helaman 11:6). Clearly the planet earth was not struck with a famine, only the Nephite and Lamanite lands. When the sign of Christ's birth appeared in the heavens, "all the people upon the face of the whole earth from the west to the east, both in the land north and in the land south, were so exceedingly astonished that they fell to the earth" (3 Nephi 1:17). Notice again that Mormon₂ was describing the extent of Nephite/Lamanite lands, and calling them "the face of the whole earth." At the end of the Jaredite civilization, Moroni₂ lamented that "there were none of the fair sons and daughters [of the Jardites] upon the face of the whole earth who repented of their sins" (Ether 13:17). Clearly Moroni₂ wasn't insinuating that there were Jaredites on every continent of the planet earth.

For Samuel the Lamanite, "this earth" and "the whole earth" were synonymous

Samuel the Lamanite prophesied that, when Jesus died, "the rocks which are upon the face of this earth, which are both above the earth and beneath…shall be broken up; yea, they shall be rent in twain, and shall ever after be found in seams and in cracks, and in broken fragments upon the face of the whole earth, yea, both above the earth and beneath" (Helaman 14:21–22). Notice that, for Samuel, "this earth" and "the whole earth" were synonymous: They were, from his perspective and the perspective of those who heard him, the same thing. Likewise, he prophesied that "darkness should cover the face of the whole earth for the space of three days" (Helaman 14:27), i.e. the lands where the Nephites and Lamanites dwelt.

And so it was fulfilled that "the whole earth [did shake] as if it was about to divide asunder" (3 Nephi 8:6; cf. 8:12), "the face of the whole earth became deformed" (3 Nephi 8:17), the rocks "were broken up upon the face of the whole earth" (3 Nephi 8:18). Again, this didn't mean the planet earth, but rather the Book of Mormon lands.

When the darkness fell upon the Lehite people, the text tells us that it was "upon the face of the land" (3 Nephi 8:19; 10:9), which, from the perspective of the ancient authors, was synonymous with "the face of the whole earth."

One of the greatest challenges we have today is reading the scriptures in the mindset of the people who wrote them, who had different scientific and cultural understandings than we do.

Notes

Question: How did ancient people of the Old and New Worlds view the "the world"?