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.

I think the rising and falling popularity of areas like hard SF and far-future SF is, to a considerable extent, the same as any other fashion.

Usually if nobody hates a piece, nobody loves it, either; and a magazine which sets itself the goal of provoking thought is not doing its job if everybody agrees with what it does.

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.

And, of course, some SF is set close enough to here and now that Anglo and European do apply. Since many of the writers come from those backgrounds, so does much of the fiction.

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.

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.