Yeah, I've read some of the Atomic Rocket stuff, and got a pretty good understanding in general of what can and cannot be done in a semi-hard sci-fi space opera.
My FTL-variant is a bit problematic though as it works differently from the stereotypical version (cross-post from one of the short-novel threads):
The second type of FTL is not actually FTL, but teleportation. Sort of.
At least, it is no different from deconstructing something, and transmitting the data to another place and reconstituting the target there.
It has no issues whatsoever. Probably. FTL speed is problematic, not sure about traveling exactly at the speed of light. If that might have issues, reducing the speed to 99.999...% of lightspeed sure gets rid of that issue, though now the instanteneous acceleration is more problematic...
The first form of FTL still has all the issues associated with FTL. Information is transmitted instantly (from outside POV, which is what matters, all people must be able to agree on the order of events or there will be issues), even if it ages during transport. Indeed, it is not really different from any standard FTL, even if it looks like that.
Not that the causality issues ever prevent people from using FTL.
I think I got a semi-solid explanation in place, and as the principal controllers of the technology are AIs I can apply some handwavium on any unintentional effects that reader might figure out from the rules in place such as, someone suggested in the other thread, nestling fields within one another. I do so by borrowing a page from Banks there and taking it further, never attempting to show the PoV of the AIs so that I can leave the exact ramifications of the technology as a mystery (Why don't the AIs use technology to do X? Who knows, they are too intelligent & enigmatic for baselines to figure out).
Not sure that works. It is a handwave, possibly hidden by smoke and mirrors but that doesn't change the fact. As we know, however, an average reader has no problem with FTL, handwaved or not. Not that all handwaves are bad, they just can lead to fridge logic.
So, the question is,
how much does it bother you, and how much does it bother you that some people will be bothered by this handwaving?
Also, there's another issue: If AIs won't do something that is implied to be possible (or what the readers figure should be possible), what prevents other people from doing that?
Unless you bind AIs to the FTL devices themselves (or are the only ones who can operate them), which means both are kind of magic.
Well,
FTL is magic already, no matter how it is done.
Of course, you could handwave some sort chronology protection agency, perhaps the AI/FTL devices could be that. Would avoid causality issues but would lead to others... Requiring some sort cosmic system to keep the universe's chronology straight has its issues.
(Personally, I'm inclined toward using non-FTL instantenous-from-the-traveller's-POV travel, ie lightspeed-limited teleportation, something like your second-type FTL, or wormholes, with working chronology protection conjecture to prevent time travel (ie if the holes are not synced, you can't travel backwards in time, the wormhole collapses if the sync is lost or something like that. The good thing in this is that this concept has some basis in reality, though only on conceptual level, but i think that's better than nothing).
This way i'll probably avoid most problems reasonably. Of course, these wouldn't necessarily be good for a space opera, at least not for one with spaceships (wormholes arguably negate need for spaceships, as do most teleporters, depending on how they work). Of course, one can always tweak the rules for these until spaceships are required or practical.
Wormholes still have some big issues, like enabling simple relativistic bombs...)
A bit worried about AIs turning into Deus Ex Machinas, by going "Because AI", but one of themes I'm interested in is that of "What would humans think if they knew they were eclipsed by beings that are significantly more intelligent and creative than them?"
No conflict in the story will ever revolve around humans vs "big bad AI", but rather "humans vs humans" (or baselines, those beings that are equivalent to the human baseline) and "humans directed by AI vs humans directed by AI", as pitting a self-evolving artificial intelligence against what in comparison looks like an evolutionary dead-end is not a fair fight.
Got plenty of explanations for why humans are still around, and each one of those explanations can provide all sorts of explorations of human nature (they are all true, as there are different AIs who - from a baseline POV - behave differently. Or maybe it's one AI pretending to be multiple ones. Who knows? 'Tis a mystery).
AIs won't be Deus Ex Machina, unless you use them like that.
Rather, they're just gods on the backround (ie, Deus Est Machina, pardon the pun), based on how you describe them (so, humans vs humans ain't any different from different religions or political ideologies fighting each other). Which makes wonder, what's the point?
If they're actively doing things, then you need clear rules for them, and the readers must understand those, or they will feel like deus ex machinas or asspulls.
I'm not too keen on Singularity AIs, because they either end up being gods (perhaps physical ones), or something that is informed to be highly intelligent but without actually being that. Informed abilities or attributes are no good. Show, don't tell.
I linked two Brandon Sanderson's essays for bengraven above, the
first one is definetly something that you should read as well, for the principle applies here as well.
"
Sanderson's First Law of Magics: An author's ability to solve conflict with magic is DIRECTLY PROPORTIONAL to how well the reader understands said magic."
Substitute AI for magic, and something for "solve conflict" and the law doesn't change at all in spirit.
Read the second one while at it as well, it is also very interesting, dealing with limitations of powers.
I think Peter F. Hamilton made great use of super-intelligent AI in his Commonwealth Saga. The AI was a bit mysterious (its capabilities, intelligence were left mostly to mystery) but also disconnected from human affairs mostly, so it didn't interfere with the story while making an interesting backround element. (And arguably one that could be cut, with some modification to some characters).
