Clarification from FE Wiki?

I'm currently working my way through the articles.......

"The earth is physically much larger, of course. A circle with a diameter of 25,000 nautical miles across is simply the area of land which the light of the sun affects, and represents the area of our known world."

Forgive me if this is obvious, but is this statement suggesting there are areas of the earth we don't yet know about? Like land masses and stuff? I've only known for about 3 hours that some people still hold the belief that the earth is flat, and I am still sorting through information. There is just SO much to sift through and process though.....

I'm currently working my way through the articles.......

"The earth is physically much larger, of course. A circle with a diameter of 25,000 nautical miles across is simply the area of land which the light of the sun affects, and represents the area of our known world."

Forgive me if this is obvious, but is this statement suggesting there are areas of the earth we don't yet know about? Like land masses and stuff? I've only known for about 3 hours that some people still hold the belief that the earth is flat, and I am still sorting through information. There is just SO much to sift through and process though.....

If we don't yet know about them, then how can anyone answer your question?  We could speculate about these unknown areas, but all we can answer with certainty is about the areas we do know about.