Zeerust is a term defined as concepts that looked futuristic when they were produced in fiction, but that to a modern audience seem old fashioned.
Some examples would be women not being allowed in positions of power, or the USA and Soviet Union still in a cold war in 2185.
My tip? Don’t ever give tech specs! R2D2 still seems futuristic because there aren’t droids wheeling around with his capabilities. But when Data from TNG is said to have an amazing memory capacity in terabytes, a capacity I could now purchase for a couple thousand dollars it dates the material.
For that matter, never say the year if you can possibly avoid it, or if you absolutely must give a year, put it well after the end of your expected readers’ lifespans, and preferably on a new calendar. We don’t have HAL yet, but that’s OK; maybe we will someday. But we certainly didn’t have HAL by 2001.
Why avoid it? Norman Spinrad’s Russian Spring postulates a future where the Soviet Union is the world’s biggest superpower, under a slightly reformed old-line communist government. It came out in 1991, just after the Soviet Union dissolved.
But it’s still a pretty good novel.
Isaac Asimov famously wrote a story where he predicted that Mt. Everest would never be climbed. It appeared in print six months after Hillary and Tenzing got to the top.
Petabytes. 800 quadrillion bits is 100 petabytes, which equals about 97,656 terabytes. And remember, it is not the memory size itself but the positrinic pathways that determine his computational abilities.
Besides, science fiction (like all literature) is about the time it was written, despite having the trappings of “the far-flung future world of 1967.” SF writers rarely intend to be prophets although that is part of the game.
Zeerust adds to the charm of the older stories, much as Dicken’s language fills out his novels.
Don’t postulate almost unimaginable technological advances in the near future. No, we will not have time travel, interstellar flight or antigravity in thirty years; or fifty, or probably even a century from now.
There’s no avoiding zeerust, because your material is going to be technologically dated as much by what you don’t include as by what you do. Look at how many older works are dated now because their authors didn’t imagine cell phones or the internet.
Technology will not go the way you portray - the things you show will not happen (at least not in the way you show them), things you don’t will.
Politics and society will laugh at your puny attempts to predict their flows.
Fashion…there’s a good chance fashion will straight up sabotage you if you get popular enough to influence trends, taking your ‘futuristic’ looks, and making them ‘current trends’ and thus quickly dated.
There is one way to avoid zeerust. Set your story in the present, don’t make any aesthetic changes. Change only what is the point of the story. Your story will still become dated, but it will become dated in the same way as any other contemporary story, rather than zeerusting out.