Just a couple of decades ago, one noted, the only people who firmly believed that there were planets circling other stars were science fiction fans. Now we’re discovering new planets all the time, and some estimates suggest that there may be billions of these exoplanets throughout our galaxy. So that’s one reason to be talking about interstellar travel: Now there’s somewhere to go.
Another reason is that while talk is no substitute for action, it can be a pretty important precursor. Much of our progress in space to date has been achieved because of people (usually science fiction fans) who wanted to explore places where no human had ever gone. As physicist and science fiction writer Greg Benford remarked, ultimately, we can do this, “but you can’t do it if you stop thinking about it.” Science fiction keeps people thinking about it, and that’s good.
As Glenn is fond of saying: “Faster, please!”