I see no reason not to give a fair degree of latitude to such questions. not everything is T-SQL (gasp... what he said?!?) Why you could say it 'broaden's your horizons', and promotes more than two dimensional thinking.
So I could submit a question about solar flares or harmonics?
If you can somehow relate it to how you store, retrieve, or query against data pertaining to such things in SQL, then why not? The first might make for a good example of a table that would need to contain a very interesting variety of data types (spatial, time of occurance, time duration, size (surface area and/or volume), intensity etc.) So who knows, might be an interesting question to be had that involves such things and sheds light on a new area people had not throught about before.