2. Antigravity love songs

Related to the above, with Star Trek again the main offender, although it happens everywhere. We find the idea of sex with our nearest evolutionary relative, the chimpanzee, repellent. And yet we are quite happy with the idea of Captain Kirk doing his interplanetary swordsman thing with a variety of smokin’ hot space babes. He might as well try it on with a nematode worm: at least it has DNA.