"Is that so?"

Somehow my posts over the past week or so turned into a series about "so".

http://upgradeenglish.blogspot.com/2009/07/so.html
http://upgradeenglish.blogspot.com/2009/07/more-about-so.html
http://upgradeenglish.blogspot.com/2009/07/even-more-about-so.html

There are at least these two things left to talk about.

First, "so" can be used like in the sentence above. It's used to show that a number is approximate.

近似 (きんじ) (n,vs) approximate; proximate;
近似値 (きんじち) (n) approximate; approximation;
○ He's about 50 or so.
○ A: How many people were there? B: 100 or so.

Don't use it like this:

× It was green or so.
○ It was kind of green.
× We were happy or so.
○ We were somewhat happy.

Tomorrow there's an eclipse. It's the longest one of the 21st century, according to the press.

• eclipse of the sun
  日食｛にっしょく｝

http://news.bbc.co.uk/2/hi/science/nature/8161578.stm

"Is that so?" you might ask.

Is that so? そうなんですか。／そうなの？◆言い方によっては「ふーん」という風な、あまり興味がない様子を表す。そんなものなのだろうか。◆【出典】『ナンパ天国ニッポン』（ひらがなタイムズ編）／株式会社ヤック

Yes, really!