How to express this idiomatically?

The only expression I can think of that is similar is the rather dry and scholarly: matter expands when heated and contracts when cooled (with the notable exception of water).

Common use for "swelling" is more likely in reference to a human or animal's body, otherwise known as edema. I'd be just as likely to use "swell" in the phrase "swells up" -- After the mosquito bit me, my arm swelled up or my arm became swollen.

Typically, I think I would never say that inorganic matter "swells," except that a river might be swollen or I might refer to ocean waves as ocean swells. I might also use the word to refer to an emotional state, as in "I swell with pride to think of my child's good grades."

Oops, my English-Chinese dictionary has trapped me in the usage of swell. Thanks Piffka.

In addition, the expression "matter expands when heated and contracts when cooled" sounds a bit long and seems not so convenient in colloquialism.

Can we just say "heated-expands, cooled-contracts"?

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PS. I didn't get what "There's got to be some heads that fall."
means. It sounds like "fallen heads = chopped heads"?

Sen. John Warner, R-Va., the committee chairman, called the alleged abuses "as serious a problem of breakdown in discipline as I've ever observed." Sen. John McCain, R-Ariz., a former Vietnam POW, called Rumsfeld's failure to inform Congress "egregious." Sen. Jay Rockefeller, D-W.Va., said, "There's got to be some heads that fall."

"Heads will fall" is a common colloquial expression, meaning, "Someone will have to pe punished for this," or "Someone will have to pay for this."

Too bad no dictionaries, at least those in my hand, can help explain this simple colloquialism.
Thanks Merry.

You're welcome, oristarA. Sometimes the expression is also "Heads will roll." Means the same thing.

Actually "heads will roll" comes from the French practice of using the guillotine to terminate the lives of miscreants. The head would roll into a basket. "Heads will fall" sounds like a corruption of this expression.

Prob'ly so. Still means the same thing.

Yes it does Merry and you explained it well. I really wasn't making a correction. Not at all. Just trying to add a small detail. I'll just quietly step away from this thread.

Here's a website of mnemonics that you may enjoy Oristar... none relating to matter contracting and expanding though.

http://www.cyberbeach.net/~willows/mnemon.htm

Thanks Piffka.
I can recite the value of pi with Chinese doggerel , but I could not understand how English doggerel helps students understand it.



Sir = third (quite understandable)
I = 1 (ditto)
send = ???

The number of letters in each word of the rhyme represents the decimal value of that digit. "Send" has four letters and is the third word of the rhyme, therefore the third digit of pi, (second decimal place), is a 4.

Got it now. But hey, it seems inconvenient yet. Because with Chinese doggerel, you can immediately speak out each digit exactly. I think that is why I could not figure out how the English doggerel works.

Oristar -- Using the number of letters in each word isn't very easy, that's just the way that particular rhyme works. Most people think that it is easier to remember words than numbers. I think both can be difficult.

With Chinese doggerel you say you can immediately speak out each digit... is that because the word (or word sound) has several meanings, one of which is a number? In English, we have a few: won and one, too and two, fore and four, ate and eight, but I can't think of any words for three, five, six, seven, nine or zero!

Each word of the Chinese doggerel just sounds much similar to the pronunciation of each digit, not exactly the same. But by remembering the doggerel, you can speak out the pi directly at once.

Piffka -- tree and three are pretty close. Not identical but close.

You could do it to three decimal places this way:

Pi is easy as pie --
The tree points one for one.

Doesn't make semantic sense, but it's easy to remember.

Oristar... I thought so... sounds like that's a handy doggerel verse for those times when you must remember pi.

<smiles at MA> Ah yes... so is sex and six, and we could probably find matches for the rest of the numbers that don't have homonyms. But wouldn't it be just as hard to remember as a series of numbers like 3.1415926535897932384626433832795?

Tree point one fore one fine night, too?

<applause for Piffka>