What are things we “know” about the future, because virtually all science fiction agrees?
Examples:
In the future,
there is no such thing as denim.
hinged doors are extinct (long live the pocket door!).
everything is white.
everything that isn’t white is very dark, and looks just like a boiler room.
“self-destruct” is a standard feature of all capital ships, space stations, etc.
Others?
no one shoots bullets, though swords and sabers may still be employed
military rank is based on the Navy (commanders and admirals) instead of the Army/Air Force (colonels and generals)
every fifth person is a technical/scientific wizard
everyone’s insanely good-looking unless they’re evil or overly scientific
Much like Greek Fire or Damascus Steel, the technology behind fuses and circuit breakers will be lost sometime in the next few hundred years.
Artificial gravity generators are so well made that they still function after everything else breaks and are even able to do so if the ship has lost all power.
All females (throughout the universe!) have fantastic breasts and very skimpy clothing.
There will no longer be any Muslims.
All buildings were designed by the same architect and newly built.
Or the whole world is a slum.
The speed of light is no obstacle.
We can communicate so well with aliens that we can include them in our conspiracies and intrigues as equal partners.
Planets are still where the action is; nobody builds orbiting habitats or deep-space civilizations.
War is still a major consumer of resources.
There aren’t any old people, and very few “ordinary” people. There is also a strange paucity of robots. Every now and then, a lone robot will be seen, but only rarely a significant presence of them.
People still pilot spaceships manually, for some insane reason.
Governments will be a thing of the past; we’ll all be ruled by evil corporations instead.
Except for the Amy Farrah Fowler types.
Well, that’s not really a PREDICTION any more, is it?
Having tried out democracy, we will return to feudalism and hereditary rulers once we reach the stars, because so many writers like Renfairs I guess.
Well of course we must, because if the rich find a way to isolate themselves from the rest of us - instant anarchy.
OSHA has been outlawed forcing architects to outdo each other with malicious designs to hurt and maim their occupants… Restraints and railings disappear as quickly as perilous drops from walkways come into style
Pockets are extinct, whether we all wear togas or jumpsuits.
To be really pedantic, togas are good for holding small objects; they have lots of pleats and folds. The Romans kept all kinds of crap in their togas.
But…otherwise, yeah. Pockets are damn handy, and “future” costume design heavily de-emphasizes them.
As opposed to all the devout Christians on the USS Enterprise?
Seatbelts or restraints have been outlawed on space ships, and wearing them is a executable offense. Future people have discovered it is safer to be thrown around the ship with every bump.
Also fuses and circuit breaks have also been outlawed, and computer terminals and panels are required by law to have small pockets of flammable liquid and explosives installed so that every bump will set them off.
We have much to learn!
As we travel from world to world, they each have one government, and each planet’s inhabitants all dress the same.