When you want to say something, stop and think: how might they have expressed the concept you mean back in the day?
You could:
* Watch/read other period-created sci-fi, but not exclusively. Sometimes sitcoms and (then) present-day dramas are useful, too. You could also crack open some dated textbooks/newspapers.
* Ask, on this board. We're very creative folks.
* Invent something completely new.
* Check out a dictionary for all the suffixes/prefixes, etc.
* When in doubt, describe something in terms of a well-documented historical/scientific example, or a completely made up one.
You could:
* Watch/read other period-created sci-fi, but not exclusively. Sometimes sitcoms and (then) present-day dramas are useful, too. You could also crack open some dated textbooks/newspapers.
* Ask, on this board. We're very creative folks.

* Invent something completely new.
* Check out a dictionary for all the suffixes/prefixes, etc.
* When in doubt, describe something in terms of a well-documented historical/scientific example, or a completely made up one.