乒乓 is the modern word for ping pong, based around onomatopoeia (and similarity to 兵 for phonetic element) and, as some people claim, shape. I was wondering if this shape explanation is true, or little more than a folk etymology of the word.
That is to say, are 乒 and 乓 (or one of them) used in words (or on their own) other than in "乒乓"? The easiest way is to see if these were ever used in classical chinese.
If they are true historical characters, what did they mean before? Are there any words which still use them now other than in ping pong?
Quite a diverse question, but interesting to me.