As for sticking strictly to presently known science, I will simply point out that we have already experienced at least two major revolutions in science in this century alone. ↗
I think the international appeal of SF is quite understandable since the kinds of people who like to read it, are, by the nature of the beast, interested in other cultures, of which other nations on Earth are the closest available example. ↗
Ideally, I'd like every issue to include a diverse group of stories that meet the qualifications sketched above, but covering a wide range of specific matter and flavour. ↗
Its limitations are those of the physical universe: it won't let you play with some really wild ideas that aren't possible, but are fun to speculate about. ↗
There may be something to the suggestion about the pace of technological change intimidating writers, though - it's been awfully hard to keep ahead of real developments. ↗
What SF can do better than anything else is show us the range of our possible futures, and what we can do to realize the good ones and avoid the nasty ones. ↗
