It's easy to imagine ways the future can be ugly and depressing. It's harder, but more worthwhile, to imagine plausible ways we can make it better.

Don't mistake a good setup for a satisfying conclusion - many beginning writers end their stories when the real story is just ready to begin.

When something hasn't been around much for a while, and one example of it turns up and catches people's eyes, they go looking for more like it - until they get tired of it again.

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.

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.

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.

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.