jbriggs444 said:
Zero in mathematics is also
sometimes represented by the empty set.
Therefore the empty set represents something, so it is not true that the empty set represents nothing!
Reminds me of the old joke: The pain-killer Anadin used to be advertised with the slogan "Nothing acts faster than Anadin". The joke went: What's the best thing to take for a headache? Answer: nothing, because nothing acts faster than Anadin.
Seriously, this warns us of the slippery use of language, especially in common parlance without clear definitions. As someone said recently in another thread: if you want to be clear and unambiguous, use math, not language. It is a classic fallacy to assume that if there is a word, there must be an entity corresponding to that word, about which we make statements when we use the word, e.g if we say "nothing moves faster than light", we are postulating an entity called Nothing that moves faster than light (or acts faster than Anadin). This is parodied by Lewis Carroll in "Through the Looking-glass" (‘Who did you pass on the road?’ the King went on, holding out his hand to the Messenger for some more hay. ‘Nobody,’ said the Messenger. ‘Quite right,’ said the King: ‘this young lady saw him too. So of course Nobody walks slower than you.’ ‘I do my best,’ the Messenger said in a sulky tone. ‘I’m sure nobody walks much faster than I do!’ ‘He can’t do that,’ said the King, ‘or else he’d have been here first.')
"Opposite" is also a slippery concept in ordinary language. It's often used to describe things that are often paired and contrasted, e.g. male/female or cat/dog, that are not logical opposites. The bank account illustration in post #7 is another instance.