球（きゅう）

Maybe this should be unlinked.

Why?

地球の中心から赤道のあたりまでの距離と、北極・南極までの距離は確か違いますよね？
それに地球には山とかがありますし。

そもそも完全な球（きゅう）など現実には存在しないというプラトン的な話です。

あ、すみません、ぼくのコメントに対する why ですね。

でも英語で round とか言って↑のような議論は成り立つのでしょうか？

僕はネイティブではないけど、round でも成り立つと思います。正確に言うと spherical とかでも合ってるけど、それはまた原文と違いますね。

What does it mean that something is exactly round? Is "round" a mathematical term?

Strictly speaking, the earth is not a sphere.

> We commonly say "the earth is round".
> We often use round to refer to things like ping pong balls, oranges, etc.

I know that.

Does it make sense to say that strictly speaking, oranges are not round?
Or really strictly speaking, ping pong balls are not round?


日本語でいうと、いくら厳密に言っても地球やオレンジは丸いと思います。しかしそれらは球ではありません。

This is getting interesting. :-)

> 日本語でいうと、いくら厳密に言っても地球やオレンジは丸いと思います。しかしそれらは球ではありません。

I see. Strictly speaking, you’re right since both 丸い and round (and rond in French) all mean “having a circular or spherical shape”. The *shape* of the Earth, oranges or ping pong balls is definitely circular. I was confusing round and spherical, and maybe CK too.

But I think the cooccurence of “Earth” and “round” is so high that one feels better writing “the Earth is round”, no matter the actual precise meaning of round. By the way tommy_san, the Japanese certainly has more 地球 cooccurred with 丸い than 球 too, hasn’t it?

We use to oppose “round” and “flat” while talking about the Earth. So when one says “the Earth is not round”, we tend to think the speaker means “the Earth is flat”. But if the speaker indicates “strictly speaking”, we think the speaker means “the Earth is not perfectly round” instead. This is why “strictly speaking” fits well, although strictly speaking, I don’t think it’s correct since “round” is just about the shape. :-)

Considering all this, I think we’d better translate it to sphere.

> By the way tommy_san, the Japanese certainly has more 地球 cooccurred with 丸い than 球 too, hasn’t it?

Definitely. I don't think I've ever heard 地球は球だ.

I guess many people have used the word 球（きゅう） only in math and science classes.