The most condensed definition of "virtual" that I can wrangle out of this book kind of amuses me. It's that "virtual" is used to indicate phenomena that exist, but not in a tangible, physical way. Really, it's a very nice definition, but it incorporates more than the book really discusses. To me, that definition incorporates the sort of zaniness that goes on over at Muppet Central Forum or in some of my IM conversations, in which we throw penguins and shoot water guns at each other and one friend turns into an otter while I whack the other over the head with a frying pan. Of course, we're not really doing that stuff to each other, but we talk as if we are. The real difference between this stuff and what the book is talking about is that there aren't any images that go along with me whacking my friend over the head with a frying pan. Does that make it any less real, any less virtual? Well, no, I don't think so. What you see isn't everything. One of the moderators on the forum is legally blind. Images wouldn't do him much good, but since all of our interaction is through text, he can participate just as well as any of us. If you ask me, I think that makes it more real than, say, The Sims. (Of course I'm sure plenty of people could contest me on that... in fact, I could contest myself on that.)
That's one of the points of this class, though. "Visual Rhetoric," or "Visible Rhetoric," (I can never remember which one we're supposed to use) isn't just what you see; it's what you hear, smell, feel, and think. We talk about the viewer and the spectator and how no rhetorical experience is ever isolated from other rhetorical experiences, so really it's about all of your sensory perceptions plus your thoughts and memories. The sum total of all that is Visible Rhetoric.
Anyway, getting back to the virtual. It's actually one of the problems of my life. People seem to think I need a "real" social life, not realizing that I've got one; it's on my computer. Just because I know my friends almost exclusively through IM doesn't mean they're not real, or that my friendship with them isn't as real as my friendship with people I know in "real life." I just happen to know them through a virtual space. So it's not tangible, no, but it's still real. People don't get that. It's nice to see that the text book does... in its own, indirect little way.