Ground zero and square one
Somehow the combination of the Sept. 11 anniversary and the death of Edward Teller brings this to mind:
I tend to snicker to myself when people say "We had to start all over from ground zero"; I tend to assume they really mean "from square one." But I just checked the dictionary, and sure enough, one of the definitions of ground zero says that it's a synonym for square one. If I were more of a prescriptivist, I would shake my head along about here and mutter about how the language has fallen. (But since the term was first used in 1946, I can't really get too annoyed about the adulteration of the long history of its original meaning.)
Anyway, just 'cause it's a synonym doesn't mean it can always be used appropriately. As a reminder of what can happen if you're careless with language, I re-present a tidbit from one of my columns:
I tuned in awhile back on an NPR report which discussed the aftermath of the rape of two Japanese girls by American soldiers stationed in Hokkaido. The commander of the American military base in Hokkaido was interviewed on the air; he commented that relations with the locals were strained. It would be difficult to regain their trust, he said, adding, "We'll just have to start over from ground zero."
Step one in regaining their trust: be more careful with your phrasing.