The Most Disputed SF Definition of Them All...

I just got my copy of The Oxford Dictionary of Science Fiction (look for a review in a few days) and I immediately jumped to the single most argued over definition in SF. Here it is:

hard science fiction, hard sf n. science fiction in which the technology or science portrayed in the story has been extrapolated from current scientific theories, especially in which the laws of nature (as understood at the time of writing) are not violated.

Hmm... I don't think that will stop any bickering over what hard SF is...