Asimov’s End of Eternity is a great exploration of the practical problems of time travel.

• The amount of bureaucracy and the specialist expertise needed to plan an intervention in the timeline,
• The rules for whether to even intervene,
• The observers monitoring the ‘future’ after the change to report on its success.

It’s perhaps not true/hard sci-fi, but I think Butler’s The Parable of the Sower and The Parable of the Talents are, uh, alarmingly prescient, considering she wrote them in the mid-90s and predicted a lot of the societal ills we’re struggling with now (including a fascist politician who promises to ‘make American great again’).

Have you take a look at https://en.wikipedia.org/wiki/Rainbows_End_(novel) ? Dr Vinge does “thought bombs” a lot with most of his books where you read something and he has all kinds of implications that jump out with one of his concepts.

Another of his works - https://en.wikipedia.org/wiki/The_Cookie_Monster_(novella) about simulations reminded me a lot of Stross’ thought experiments - but from the other side.

But all of them tend to have something - “Reality Graphics” in A Fire Upon the Deep, the localizer net and the Focused in A Deepness, Rainbows End above considers why you might have an underground market in Bootleg processors… Interesting stuff to ponder.

“off to be the wizard” takes the universe is a simulation trope and REALLY runs with it. I don’t know if I’d call it good scifi though…

I remember being pretty impressed with “permutation city” for it’s depiction of the consequences of being able to upload consciousness into machines.

I think Charles Stross does this pretty nicely, although his science part is not very hard science. So he’s basically not predicting anything, his science fiction is more of the “ok I know this is not real but what if it were” variety.

The Laundry Files series is “what if Lovecraft was right and there’s magic math that can summon the old gods”, but then add to it that we do have a way to do tons of math stuff in the form of computers. So of course what happens? Well, there are spy agencies tasked with controlling this, because we can’t get rid of computers, too important, but also, we can’t let that magic math run wildly.

The Merchant Princes series is “what if there was a way to travel to an alternate dimension”. So what happens? The dudes from the alternate dimension, who are the ones that discovered the secret, and come from a medieval-like world, use that to smuggle shit. They can go near the border, jump to the other side where the border doesn’t exist (or at least doesn’t exist right there) walk a couple of miles, and then jump back to our world. They of course build a massive criminal empire on our side. On the other side, they bring our advanced tech gadgets back and they are a hugely powerful merchant family. There’s also all the implications for security. You can jump inside any building as long as you know exactly where it is on the other side. And the shit the US government gets up to when they discover this exists is pretty disturbing (especially when you consider that it makes sense given what was done in the name of the war on terror).