Though I guess you can apply that to any kind of literature interest. Let me define it a bit better.
I really like it when I actually have to strain and focus while reading to make sure I'm understanding everything right, or even if I'm just understanding them at all. Books that barrage you with information, references to things of scientific nature.
The last novel I read that had thad effect on me was the book by China Miéville named Perdido Street Station. I had a hard time starting to read it, and put it on hold for almost a whole year, but after starting it again this summer I gradually sped up in reading it, and finished last month. It's a book with many really cool ideas, and what's more, it's very beautifully written. Not exactly science fiction, China calls it "weird fiction". Whatever the label, it's a fantastic read.
I just finished reading a novelette by another young writer named Charles Stross - it's called 'Lobsters', and it's available for reading online, just put his name and the novelette name into google and click "I'm feeling lucky". It's extremely powerful, and will leave you in the dust if you're not on your toes.
This renewed interest of mine in Science Fiction - or rather, a fiery drive to more actively discover new and exciting science fiction writers and books - was kindled a while ago when I read an article I found through Slashdot. It's focus was science fiction's and many writer's ailments regarding the times we live in - how technology and the world we live in are changing so fast it feels ever more impossible to try to envision a plausible future.
But the article introduced two writers who have been very active and talked about lately; Charles Stross and Cory Doctorow. I was instantly intrigued by their ideas - just their lingo they used to each other was inspiring, because they seemed exactly the kind of characters to write books to my liking.
So I scouted the web a bit, googled around. Turns out Cory Doctorow releases all his novels free online as well as in printed form - under the Creative Commons Licence. So if you're intrigued, check out
CrapHound.com to read some of his stuff.
Charles Stross has, as I noted earlier, a bunch of short stories online as well. You can probably find them on his website;
www.antipope.org/charlie.
I decided to take the chance on one of Stross's published novels, and had the University Bookstore order one for me (since they had none on sale before, despite their impressive catalogue). I've received mail about it having arrived, and I'm very excited about picking it up later today. Especially after that cool short story "Lobsters".
MMm, yes. Reading these intensive sci-fi stories is like when you fall into math text books from time to time, when you understand just enough not to be disoriented enough to have to read the page again, and just really want to drive forward.
//I apologise for weird line structure or article build-up; I was feeling a bit weird but I couldn't help it.