[NitpickLawyer]

> which is about as hard sci-fi as you can get.

Interesting, I always thought that the modern interpretation is that hard sci-fi is "rooted in science" or close to it. The ansible (i.e. FTL communication) is, to our current knowledge, not possible. But it is such a useful plot device that it could be viewed as "close enough".

I understand the opposite of hard sci-fi to be the hand wavy "magic" stuff like photon torpedoes, teleportation, phasers, hyperspace, and so on.

[scarmig]

I think the critical factor that makes sci-fi hard isn't known physics, exactly, but early on establishing a known set of rules and letting them play out as they will. The narrative has to respect and adjust to those rules, not vice versa.

This ends up driving most hard sci fi to current understanding of physics, with maybe one tweak. If you diverge more from that, it's difficult or impossible to establish the rules and their implications early on, and so choices about them later end up serving the narrative.

Though, a certain irony: hard sci-fi doesn't seem to offer much predictive insight about the future compared to other subgenres. The 20th century sci-fi genre that seems to offer the most insight into our current moment is probably the one with the wildest imaginings: cyberpunk.

[NitpickLawyer]

Heh, yeah. At least we're currently a bit more prepared for a Seveneves scenario than we were say 15 years ago.

Speaking of prediction powers, there's one that stands out and turned out to be quite prescient on a bunch of topics, both tech and social. Ender's Game was published (fleshed out, novel version) in `85 and it got quite a few things pretty accurate:

- tablets & touchscreen widely used as a common interface to content

- the Internet as a wide web, everyone using it, instant messaging, and so on

- Social networks, forums where debates are held, and more importantly sock puppet accounts and wide scale manipulation (for politics, etc)

- AI for world generation, military use for training, adaptive difficulty, etc.

In the later books there are concepts like digital currency, AI controlled corps/accounts, AI becoming "sentient" and moving itself between mediums, etc (well, that one is not yet here, but who knows...)

[ghusto]

> I think the critical factor that makes sci-fi hard isn't known physics, exactly, but early on establishing a known set of rules and letting them play out as they will

No that's just competent writing. Hard sci-fi is very much about real science.

[rpearl]

Clockwork Rocket by Greg Egan is specifically about physics which does not exist here.

"Hell is the Absence of God" by Ted Chiang deals with a world in which god, heaven and hell are unambiguously real.

Both are definitely "hard sci fi"