''There's a basic optimism to science fiction – maybe I should confine that to hard science fiction. I think the field shares the basic optimism of science itself. If there is a credo in this business, it should be a quote from Albert Einstein: 'The most mysterious thing about the universe is its understandability.' We can understand the way the universe works; hard science fiction that deals with real science and technology is about people learning how the universe works, whether that universe is the solar system, the whole cosmic wonder of it, or the universe within our own body. But you can learn, and knowledge makes us better. It makes us wiser, more capable, it improves our lives. And knowledge is always to be preferred over ignorance.

''Yet there are always forces in society that move for ignorance. They want to keep the status quo. Every institution in society except for science is built to keep the status quo. Law, religion, social customs, family traditions – they're all there to keep things the way they are. Science is constantly making new discoveries, and that's why scientists are very often looked on as scamps by everybody else – if not with outright fear. Science is always breaking the mold, finding something new. Today doesn't have to be like yesterday. Tomorrow will be different. Change is inevitable, and scientists are actively going out and making changes! They are doing it because it's fun, because they're driven to it by their own personalities. And science fiction echoes the basic optimism of science. We don't say 'We shouldn't go there because there may be dangers.' We say, 'Gee, let's find out what that's all about, and if there are dangers we'll deal with them,' because with every danger come new opportunities as well.

''I didn't realize it at first, but I've been writing a serial novel for the last 10 years – Mars, the two Moonbase books, the sequel to Mars, and Venus; now I've done Jupiter. They're all interrelated, and it all turns out to be this big canvas of how the Earth changes and how this impels and requires our expansion into the Solar System. I'll keep on writing about it until I get it finished – though it never really will be finished.

''I think of them as historical novels that haven't happened yet. My audience consists partly of science fiction fans, but mostly of people in technical fields – I sell well at universities, NASA installations, places like that. It's a technically educated audience, people who are interested in realistic stories about how you get there from here. Everybody wants to be in this wonderful future. The question I keep thinking about is, How do you build it? How do you make it happen? And what resistance do you have? Why aren't we on Mars right now? So I'm writing novels that are all interconnected.

''I'm talking about what is going on in the real world, not in science fiction. They do affect each other a little bit, but the big effect the real world has on science fiction is in the distribution of magazines and books. These days, Analog is sort of insulated from the real world, and that's what its hardcore readers want. But that readership is getting smaller and smaller. F&SF has just about given up on SF. They dropped Gregory Benford as science correspondent and added two movie columns. We've seen a lot of attempts to tie in popular movies and things with science fiction, but I don't think it really helps.

''After saying, the last time we talked, that I was just going to be a writer, I find myself back in the editing and publishing game.

''One of the first people Doug Conway, the founder of GalaxyOnline, brought in was David Gerrold, who recommended that he come to me because he was looking for a publisher. What Doug had in mind was something like Omni. He wanted to produce a top-rate medium that deals with science, the future, fiction as well as nonfiction. It sounded intriguing.

''One of the reasons I'm interested in GalaxyOnline is this may be a new medium and draw new readers into the field. A lot of youngsters are looking at their screens. They're not buying books or magazines, but they are on the Internet.

''Besides the written word part, GalaxyOnline is multimedia – it's got films and video. Right now most are short or reruns of old stuff we've taken the license for. The whole operation is deliberately aimed at people with very fast machines, because we see this as the future market. With the fast machines, you'll be able to look at films and videos in real time. With the published word, it's not that important, but even there we would like to be able to do more visuals, since illustrations to the story break up the blocks of type. We want to do audio as well. It might be interesting to have authors reading parts of their stories. It's an experiment. Moving in all these different media, what really is going to work? Nobody knows. GalaxyOnline is getting about half a million hits per month, and we are now starting to see what features people are looking at.

''Our aim is to have new material on the site every day – a new piece of fiction, a new piece of nonfiction. This changes the way publishing works. You don't have deadlines anymore. Every day is a deadline.

''The SF field has always changed, never been static. I think what has happened is that science fiction has invaded the rest of the world and conquered it. We've won. But nobody realizes that. It's like the plot of a science fiction story: the invaders have taken over the civilization but the civilization doesn't realize it. In a sense, most of the science fiction stuff people were writing about in the '50s and '60s has come to pass. We have computers in most every home. We have space travel of a sort. We have the prospect in medicine of elongating your life so far that you're virtually immortal. (It's not nanotech, it's telemerase, an enzyme. Secret of eternal youth: one bite on the neck and that's it!) There are examples of human cells that have been immortalized so they're now something like twenty times longer than their normal lifespan.

''I talked about that in Immortality. Every now and then I do a nonfiction book, and Immortality was about all this research, and then the social consequences. It may be for the benefit of society to suppress this kind of research. Maybe we can't handle a world in which nobody ages and the death rate goes down almost to zero. It may create such intolerable strains on society that it would be better to do without it. But once people realize they can live forever, this kind of therapy is going to be done. No force on Earth will be able to stop it or suppress it. We're going to have to learn to bring down the birth rate almost to zero, or overpopulate ourselves. Bring back starvation!"