[Gatac]

I'd say that's magic sci-fi tech. In my mind, it's not so much about whether the thing is actually explained, but how it is approached. For example, the Stargate itself, although there is obviously some theory behind it that the characters know, is never detailed enough that we could extrapolate a working "model" and predict new phenomena that happen to it. In a sense, though, the characters are as surprised as we are and genuinely try to understand it instead of shrugging and taking it for granted. Overall it's still soft, but it does have a good deal of realism in it - we see them reverse-engineer and slowly adapt alien technology to their own ends. As so often, human genius and adaptibility triumphs.

Hard sci-fi I like...well, let's see, that's gotta be a book. Stanislav Lem's The Astronauts has many failings - the obligatory Communism stuff (since it's a book from behind the curtain), several flat passages - and it's approach to space travel is a tad naive, coming before we really reached out to space. That said, there's a fascinating atmosphere in the whole book, and our main heroes are scientists trying to figure out what is essentially a gargantuan logic puzzle on another planet. Along the way, the book manages to take a look at several fascinating phenomena, tests theories about these and comes to a grim conclusion about the whole thing. It's slow, but a good read.

I'll just echo the sentiment: hard sci-fi is about the science, soft sci-fi is about the fiction. That doesn't mean one is better than the other, but people do have their preferences.

Gatac