There are similarities but Fire is more of a space opera and Deepness is more of a character drama. The tech details in Fire are more fantastical since they involve superluminal communications/travel and the book centers around the mechanism that makes that possible. I like Fire more because I like the pacing and the xenos better (space operas are fun) but the tech and its implications are far better in Deepness. I like the depiction of computing/programming in both and both have the history of technology as a major theme, which is one of my favorite topics.

In contrast with most of the opinions here, I prefer Fire Upon the Deep. I think the alien species it explores is much more interestingly non-human than the one in Deepness in the Sky and that the bad guys in Deepness are kind of comically over-done. They suffer from a common problem where the bad guys have to not only be bad for main reason X but also are sadistic rapists, torturers, etc. on top. As if we didn't already get the "they're bad" memo already. Plus all the action happens in the finale and, to a large extent, outside of our view. Still, both are great books, but I'd recommend Fire to anyone first.

If I'd rate my current collection of best SF I've read:

- Deepness in the Sky: super mustache twirling, one of the worst.

- Fire upon the Deep: I consider the blight to be twirling. Why treat lower civ that way? AFAIK, for mustache twirling.

- Iain M Banks: lotsa mustache twirling. Surface details and Player of Games in particular. My view of the culture AI is that they are constantly sarcastically toying with humans, and are thus secretly twirling.

- Fifth Season (Jemisin): no twirling. One of the most balanced novel on that front, every faction has believable reason to act the way they do.

- Book of the New Sun: no twirling, but OMG, stop what you're doing a good read these books! The tone and story was just perfect for me. Sure, it looks like a weird cross of SF and fantasy, but there is no fantasy at all in the novel in reality. Book of New Urth is, in comparison, just merely very good.

- Ancillary Justice (Lecki): some small twirling, but justified since it's an empire: absolute power corrupt. The twirling is commensurate with having a empress as head of state. She even becomes mostly sympathetic later.

- Left hand of Darkness: not only no twirling, but the power struggle is extremely believable. Great illustration of an interesting alien civilisation. Great for both world-building and character building. Another of those stop everything and just read it now novel.

- Roadside Picnic: no twirling. The conflicts and abuse of power are all believable.

- Collapsing Empire (Scalzi): lot of mustache twirling. Not DotS level, but not that far off. Plus, there is a plot point in the first novel that made me quit reading for a week. Incomprehensible because it was all of unbelievable (given the multiple characters behaviour before), idiotic and had zero impact on the rest of the book... so why write it. (Page 260 in my paperback version, for the record)

I think he says early on that the archive trap doesn't have self-awareness, except for a few subroutines that need to be self-aware like the simulations of the researchers which facilitate the escape. Even the name blight evokes a fungus. I was thinking of it's cruelty to lower civs as analogous to the cruelty of a fungus secreting an antibiotic.

Hunting down the OOBII comes down to the escaped personae having data that could be used against it by another power.

> Iain M Banks: lotsa mustache twirling. Surface details and Player of Games in particular.

I think both the Hell faction in Surface Details and the empire in Player of Games have reasons to be as nasty as they are; they're somewhat internally consistent, in that the social stability of both the Hell faction societies and the empire are dependent on the nastiness. There are, unfortunately, real life examples of this. Veppers is a bit gratuitous, granted.

In the Fifth Season, the entire planet is a mustache-twirling villain, sort of.

(Sure, it's revenging past wrongs... on humans, some of whom are far, far descendants of the original perpetrators, and none of whom have any idea what they're even been punished for.)

What does "mustache twirling" refer to here? Is it a good thing?

It's a reference to caricature of evil villains twirling their mustache as they gratuitously enjoy the extreme suffering they inflict upon others with no rationale other than enjoying being evil.

Thanks, I get it now and basically agree on the ones I've read too. I did feel like I missed some of the motivations for some factions in the Fifth Season series. I've added Book of the New Sun to my wishlist.

They are similar in that there are two different stories that are related but don't really converge until the end, and that a primitive alien culture is explored in one of them and an advanced human[0] one in the other. They differ primarily in that Fire has a hand-wavy way of allowing for impossible technology like FTL.

Personally, I think Deepness is the better work, but Fire is pretty good too. If you read Deepness first then, because it was written second, at least one character may seem a little off for reasons that will become obvious.

[0] The characters we follow the most are human anyway.

You will also miss a lot hints about the odd things that happen around the On/Off star - almost as if there was something different about that volume of space...

Maybe I missed something about the location, but I thought the On/Off star was just inside the Beyond, where a lot of advanced technologies start working, and had the remnants of a Beyond civilization (including antigravity materials)?

I don't think On/Off was in the Beyond zone.

The actual On/Off star was presumably powering a zone changing device of some kind - antigravity technology had remained working for millions of years which made me think it was in a bubble of High Beyond or Transcendent zone levels (like the ending of AFUTD).

They did also say in AFUtD that the Zone boundary isn't smooth and continuous, it's like a foam with ripples and bubbles near the boundary and moves around some normally -- which is why ships that ply the Low Beyond near the Zone boundary always carry coldsleep units and ramscoops as a backup.

Did we every get an in universe or author-commentary explanation confirming the theories about the On/Off? I always figured it was some high-tech artifact based on Beyond or Transcend tech that was going to remain mostly unexplained?

In-universe, there's a conversation between a couple of the focused near the end of chapter 15. One of them speculated that it was a fast square wave generator.

Discussed up-thread: OnOff has an eccentric orbit, and I think we're meant to infer that it was in the Beyond or Transcend at one point. (I think the characters draw the wrong conclusion about which part of its eccentric orbit was the interesting one and we're meant to read it as horribly ironic that they're planning on going entirely the wrong way. But someone else concluded from Fire that the galactic core also had interesting activity.)

Both are glorious books - I didn't like The Children of the Sky though.

Larry Niven, a similar kind of a scifi writer, said that when a writer is so successful they quit their day job, they lose that source of inspiration.

Vinge retired from lecturing compsci in 2000. Deepness was 1999. Children was 2011, was competent, but lacked almost all the clever insights of the previous novels. I wish he'd go back.

Oh well, he gave us several very good novels and 2 great ones. He deserves a break!

I'm not sure why that would be especially true for writers in general. If anything, I expect it would be more about reverting to the mean given that Fire Upon the Deep is one of the all-time great SF stories.

I think it can happen in some circumstances though. For example, Dilbert still feels largely locked in some 1990s PacBell cubicle land.

Not very difficult to think of counterexamples to that rule: Iain Banks, Neal Stephenson, Charlie Stross...

Charlie Stross arguably lives in a country led by New Management, so for inspiration he only needs to launch BBC these days...

You're not supposed to refer to the Dark Lord Cummings like that, He will bear thee away to the houses of Durham, beyond all darkness...

Hmm, wasn't Niven basically a full-time writer himself from quite early on?

yah, he lived on a trust fund for the first year. I've wondered why he thought it didn't apply to him. Perhaps, being a student then writer, work was never his inspiration, he had others.

In fairness, a lot of his early stories featured people with trust funds!

Which ones? His earliest adolescent stories were buddy stories, eg Becalmed in Hell, Wait It Out. I can only think of inherited wealth in A Relic of the Empire (Rich Mann).

Been years since I read his early stuff, but as far as I remember, a lot of the early stories about teleporters (proto-Known-Space) featured youngish middle-class men in California with no apparent means of support.

I hadn't thought of it in terms of "no apparent means of support", but didn't pick up on that. There was Gil the ARM; a belter; and later Elephant (whose great^n grandmother invented the displacement booth - that qualifies!)

I feel I know the stories well, so it's disconcerting that maybe I missed something. I'll keep an eye out if I read them again.

Yes, aFutD is similar, but different enough for the preference to be a matter of taste. They're both among my favorite SF novels.

It works best to read them both, in publication order (aFutD first), because you only see the second book's layer of dramatic irony with that background. More on this in Jo Walton's review: https://www.tor.com/2008/07/19/deepnessreview/

Also the first book is shorter, and if you're like "meh" about it then I doubt you'd be into the second either.

Both are excellent, but in different ways.

I'd say that the barrier to entry for both is the same, though: Vinge's writing, while rich, is also quite hard for reading, in a sense that you have to go slow to parse things correctly. FOTD has a bit more action in it that speeds things up sometimes, so it's an easier read. But if you could read and enjoy it, you shouldn't have troubles with DITS.

They take place in the same universe, but are very different books. Both very good though.

Deepness has much more heart, Fire is kinda generic, with a couple interesting ideas in it.