Sci-fi uses the images that sf - starting with H.G. Wells - made familiar: space travel, aliens, galactic wars and federations, time machines, et cetera, taking them literally, not caring if they are possible or even plausible. It has no interest in or relation to real science or technology. It's fantasy in space suits. Spectacle. Wizards with lasers. Kids with ray guns. I've written both, but I have to say I respect science fiction enough that I wince when people call it sci-fi.
Ursula K. Le GuinTake the tale in your teeth, then, and bite till the blood runs, hoping it's not poison.
Ursula K. Le GuinYou fear them because you fear death, and rightly: for death is terrible and must be feared,' the mage said...'And life is also a terrible thing,' Ged said, 'and must be feared and praised.
Ursula K. Le GuinI know that nobody who hasn't been in battle or under attack can know what war is. But even in terms of being safe at home, it's also true that many Americans who think they know what being at war is, don't. Including, of course, George W. Bush and his people. They don't have a clue.
Ursula K. Le Guin