Yet, Lula, you must try to understand the translations in terms of the knowledge of the translators at the time of the translation. "World" can mean "known world" as was, I think often the case in ancient times.
Sodaiho, you don't understand the severity of the problem.
Even if the translators had known what we know today, the remains a problem in as much as "earth" then did NOT mean what it does today.
Latin "terra" meant "region" or "land" originally. Hence the words "terra incognita" on maps (for unrecognised LAND) and hence the English loanword from Latin "territory". (And a "terrarium" does not contain a planet either.)
Only slowly did the word "earth" develop its new meaning "planet earth" over the last few centuries. And it did so at differing speeds in different languages.
In American English the word "ground" has very much replaced the word "earth" for the original meaning. British English still uses "earth" for what Americans call "ground".
In German the word "Erde" (cognate, i.e. derived from the same Germanic word) has only less than half completed the transition and most people would think "floor" rather than "our planet" when you say the word. In German you literally say "my cup fell onto the earth" and it means "fell onto the ground". It's dying out, I think, but it's still at the stage where the word is mostly understood to mean "ground" rather than "planet earth".
The translation as "earth" (meaning "ground") was completely correct and still is, IF one knows that of the several meanings of the word "earth" it is the "surface" meaning that is meant, not the "planet earth" meaning.
The Afrikaans word "Aardvark" means, literally, an "earth piglet". The word does NOT refer to a piglet that has a special connection to planet earth (for example a piglet that lives on earth as opposed to those that live on Mars), but it refers to a piglet that has a special connection to _the ground_ (as opposed to other piglets that do not have that particular connection; perhaps they don't dig as much).
I don't know how better to explain this...
The word "girl" used to mean a child of either sex, in Middle English. Now it means a female child (or even any young unmarried female). If the word "girls" were used to translate "yaledim", the translation would be correct (because "girls" means "young children of either sex"). But a few hundred years after the translation was written, the word "girl" developed a second meaning: only female children. And at some point the first meaning died out.
And if the Bible made a law for "yaledim" (i.e. boys and girls) and the English translation said only "girls", we would have the same argument. And Lula would tell us that she knows what a girl is and that is good enough for her, and the original meaning would be lost, because of people like Lula.
So we have two problems here:
1. Hebrew words do not perfectly map onto English words. Any translation therefor involves interpreting the text (and hence changing its truth value).
2. Hebrew words change their meaning as do English words. And once we have an original and a translation and both contain words that likely change meaning into different directions.
The first problem causes both "eretz" and "adama" to be translated as "earth". Germanic languages have only one word for the surface and the material. (On the other hand Hebrew has only one word for "thing" and "word" - "davar".)
The second problem causes the meaning of the text to change. If we freeze the meanings at a certain point in time it might be too early or too late. (The method I use is common sense.) "Shana" meant "something that repeats" at some point and "year" at a later age. Both meanins co-existed for a long time. The trick is to figure out when it means what. As I said, common sense tells us that it meant "something that repeats" when describing that somebody is 600 shana old and "year" when it says that some king ruled for 30 such.
(Incidentally, the plural "shanim" appears to be used in the Bible when the word means "year" while the singular "shana" is used when it means "something that repeats". But I haven't found all occurences of the word yet.)
But there is solid evidence that the meaning of "eretz" did NOT change from "planet earth" to "land".
First, people 3000 years didn't know about the "planet earth" they only saw the surface, i.e. land, as opposed to the heavens (the thing above it). Hence they could NOT have used a word to describe something they didn't know existed as a thing. Hence "eretz" could only mean the surface, not the planet. Also devidence from other languages suggests that the meaning would change FROM surface TO planet rather then vice versa, since mankind learned about the surface BEFORE they learned about it being a planet.
Second, G-d knew the difference between the surface and the planet and hence would have used TWO DIFFERENT word to describe them. (And He does, in fact, use the term "haKol 3olam" when He refers to the entire world.) The reason He used THE SAME WORD was because He was talking about THE SAME THING. (And, in Hebrew there is only one word for "word" and "thing" anyway, making this even more ridiculous.)
If anybody thinks that an Israelite reading Noah's story in 1000 BCE had an image in mind of a ball completely surrounded by water, I cannot help any more.