Where It All Goes Down
SPACE! (and some planets along the way, including Earth)
Now
Okay, we're not going to lie: there are some things in Hitchhiker's Guide that scream 1970s. For instance, digital watches are cool in this book, which makes it sound like it was written in the Dark Ages. (Seriously, when was the last time someone said, "Check out my bodacious digital watch"?) But even though some part of the books are dated, Adams never specifies in what year the story is taking place, and that makes the action in the book seem a lot more now-ish than it might otherwise. After all, people's houses are still getting knocked down for dumb reasons every day... It's likely that Adams didn't specify any date precisely because he wanted the book to seem fresh and relevant years on down the line.
Earth: Stranger than you think
In classic sci-fi style, Adams starts out with a world that seems completely normal before it starts getting weird. Hitchhiker's Guide opens in the West Country of England, which is pretty much normal, Everywheresville UK. Not a lot of time in the book is spent on Earth because, as the introduction makes clear, Earth isn't very important to most of the rest of the galaxy. In fact, it's "an utterly insignificant little blue green planet." The sun itself is a "small unregarded" star, and this whole part of the galaxy is (oh dear) "unfashionable" (Introduction.1-2). In other words, we might think we're pretty hot, but no one else cares about us—we're legends in our own mind, but only there.
Sorry, Earthlings. The aliens are just telling it like it is.
However, by the end of the book, we learn this truth: while no one in our galaxy cares about Earth, it's very important to the pandimensional, hyperintelligent mice. Everything we thought we knew about Earth proves to be wrong: it's a computer built by aliens who buried fake dinosaur bones in it. Also: Norway's fjords are an award-winning project, not just a cold place to spend the winter.
So, let's review. The book starts in what seems to be a normal place, but this place gets weird pretty quickly. By the end of the book, though, we realize something: our home has always been weird, and we've just never thought about it. That's one reason we care about this book: it makes us reconsider the things around us. And most things, when you get right down to it, are pretty weird.
Damogran, Magrathea, the mouse planet: Less weird then you think
In contrast to the Earth (which turns out to be secretly weird, unlike our weird uncle who is openly weird), these alien planets turn out to have a lot of ordinary things.
For instance, when Zaphod is on Damogran, we hear about the amazing technology and aliens involved. For instance, the Heart of Gold was created by lots of scientists, including "a few reptiloid atomineers, two or three green slyph-like maximegalacticans, an octopoid physucturalist or two and a Hooloovoo (a Hooloovoo is a super-intelligent shade of the color blue)" (4.22).
We love how that list of alien scientists includes lots of weird words that seem to make sense—"atomineers" looks like a combination of "atoms" and "engineers." But then the sentence ends in the really strange example of an alien who is a color, which is easy to say but hard to imagine.
And yet, even though that's really alien and weird, the similarities between Damogran and Earth are clearly marked: Zaphod is the president and everyone wants to watch him or meet him. Even though these scientists have done something amazing, "still the greatest excitement of all seemed to be to meet a man with an orange sash round his neck," which is a reference to the president (4.23). Even though the cameras on Damogran are robot cameras, they're all watching the president, just as they would be here on Earth, hoping for some great quote—or for some fun gaffe for them to make into a big story. Even Damogran probably has annoying 24-hour news networks.
The other planets we see might be strange in some ways, but in other ways we can see elements of Earth in them—and that's one more way that Adams reminds how truly weird Earth itself is.
Space: as easy to get lost in as an IKEA
We don't see a lot of space directly, which is good, because too much direct exposure to space would kill us. But space is where everything else is, so it's worth looking at. As the Hitchhiker's Guide (the book inside the book) tells us, space "is big. Really big. You just won't believe how vastly hugely mind-bogglingly big it is" (8.3). In fact, it's so big that it's hard to imagine. No, scratch that—it's impossible to imagine for us: "The simple truth is that interstellar distances will not fit into the human imagination" (8.6). The Hitchhiker's Guide (the book by Adams) just comes out and tells us this stuff in pretty plain language. But why?
Perhaps because the truth of space is pretty meaningful here. Space is huge, and we are just a tiny part of it. So all of our ideas about life and the universe (and everything) may be absurd because we tend to think in human terms while the universe is much bigger than our concerns. Right now, we're worried about our Rock Band score; but if we compare Rock Band to, like, the entire universe, we have to just fess up and say that our issue seem totally small and unimportant.