how to simulate the emptyness of space in unity?

Hey, i was planing an idea for a space game in my head but then i noticed one thing: how do you simulate the emptiness of space? you could just use a ton of space but isint that resource intensive? the games has to keep track of so much space then. a other thing you could do is to just make everything move very slow to create the ilusion that your fast. but then you would see that at things that are not slow. and at that point i confused myself so much. now im here asking this question. thanks for the help