I’ll admit, the title seems like a paradox in itself. Science fiction is often supposed to be quite the opposite of realistic—as undoubtedly few of us will attain the experience of intergalactic battle or black hole

But writers can only defy gravity so long (sorry, Elphaba) before discouraging readers. Creating a fantastical world has its limits before it seems like, frankly, the writer didn’t do his/her research. So, all in all, here’s some tackle tips to taking on that challenge.

1. Considering the Humanoid Form

There is really no reason for your alien to look human if there is no specific reason. Yes, and that means leaving the familiar sight of the four-limbed anthropoid we know and love—because the human being has evolved specifically for the environment on earth, it’s not quite plausible to assume the alien world carries those same conditions that perfectly suit lungs, legs, or hands (or maybe it suspiciously does: and that’s a plot point). So get creative, my friend!: envision a different environment, and, if you’re brave enough, even shoot for the elements. It’ll make it significantly easier to draw conclusions about your new alien form from there.

2. Tech Tech Tech

Yes, sadly, not everybody has a five-star production tech team like George Lucas behind ’em to create iconic images (like the Millennium Falcon). But that doesn’t restrict you: imagination is just as boundless as space, if not more. Outline technology that identifies your fictional world from the mainstream. It doesn’t even have to be as expansive as it seems; for example, the staples of sci-fi warfare, such as guns and spaceships, are in such desperate need of reinventing that getting creative might just redefine the way your reader imagines your universe.

3. Concepts of Space and Time

There’s actually a reason Guardians of the Galaxy are “of the Galaxy.” The word ‘universe’ is so interchangeably used with widely different terms, such as ‘galaxy,’ that many people start to overestimate the wide expanse of space. When really, most of us have absolutely no idea how HUGE it is. So keep that in consideration when you try and map out universes, galaxies, and grand black holes that grievously endanger your protagonist’s race.

Another thing is many sci-fi writers neglect the fact space and time is hopelessly correlated. You can either let that trip you, or take the rope and turn it into something spectacular: interesting things happen when time slows down, or when you get shrunk and time speeds up.