Meta raised its head again, in a big way, in discussion of the last couple of posts on FTL. This should not be a surprise, because the rather problematic physics of FTL brings us very close to the boundary line between science fiction and science fantasy. (Including the question of whether it is valid to distinguish them at all.)
The perspective of this blog from its beginning has been that SF is a subgenre of Romance, a term now narrowed down by marketers to a different subgenre of itself. Romance in all its subgenres is distinct from 'realistic' fiction, which is largely why academic literary criticism has been rather nonplussed by it. Realism, in this context, is mostly about psychological realism in characterization, not Realism [TM] in technology, physics, or other aspects of the setting.
Yet that latter kind of Realism [TM] is itself a very relative thing, and arguably amounts largely to a stylistic flourish. Take for example the question of space warfare, a subject that probably drew many of you to this blog.
There is, to be blunt, precious little 'realistic' about clashes of armadas in deep space. Half a century of space travel combined with enormous military budgets has shown mainly that the world's major militaries have zero interest in space armadas. The US never deployed any manned space warcraft, unless you count 'Blue Shuttle' (which the USAF never wanted). The Soviet-era Russians dabbled a bit, but soon lost interest.
For that matter, from a genuinely realistic perspective there is not much basis for any of the familiar space tropes that we know and mostly love here. The exploration and exploitation of space, as of the ocean floor, is much better suited to robotic or remote-controlled vehicles and systems. Deep space does add the complication of light lag: Teleoperators at JPL in Pasadena can't guide machines on Mars in real time. But this is only a limited constraint, and - let's be honest - there are cheaper and more convenient workarounds than sending hundred-ton human habs to Mars, at enormous cost, plus the even more enormous cost of bringing them and their crews back safely.
Any number of unforeseen circumstances might change all this, and provide some McGuffinite that justifies extensive human space travel. We have discussed such possibilities before on this blog, and you can safely guess that we will discuss them again.
Stories about space travel, on the other hand, require no such hypothetical McGuffinite. It is sufficient that space travel is Cool. But even fictional space travel is subject to the willing suspension of disbelief.
How disbelief gets suspended, and in what ways, is in fact arbitrary and genre-dependent. Practically all fiction, including realistic fiction in the conventional sense, expects us to take its characters as people, not figments of the author's imagination. Even traditional literary criticism joins in this pretense, talking about Achilles or Elizabeth Bennet as if they were actual people. Experimental fiction that overtly admits to being fictional is arguably 'metafiction,' while time-honored framing devices for fantastic fiction, such as the old lost manuscript, have long fallen out of active use, and would be evoked today only for retro flavor.
I have an aesthetic bias in favor of the trappings of Realism [TM], both in the technical details of spaceships and the social details of why someone is paying to have them built, which is why Rocketpunk Manifesto belabors all of those questions about why people might actually go into space in large numbers.
It is important to emphasize that this is precisely an aesthetic bias, and my biases can be amazingly idiosyncratic and narrow. For example, spaceships that look like the Navajo missile of the 1950s are both coolific and Realistic [TM] in my eye, while spaceships that look like a V-2 with wings look corny, dated, and implausible. Never mind that they are both equally genuine design concepts, little more than a decade apart and both more than half a century old - or even that one evolved directly from the other. One looks right to me, while the other doesn't.
Many of my SF biases are reflected by the Tough Guide to the Known Galaxy, from my old static website. Even though it is largely a snark at convention space-fiction tropes, fundamentally that is still how my tastes run. I neither apologize for those tastes nor defend them. These tropes are a perfectly legitimate branch of SF as it has developed over the past century or so, but by no means the only perfectly legitimate branch.
From one perspective, science fiction itself is obsolete - a creation of the industrial revolution, an inherently transitional phase when visions the pre-industrial world could scarcely have imagined became possible to think about, even if some may never be possible to achieve. It is really, really hard today to come up with SF ideas that have never been written before.
On the other hand, SF has permanently expanded the frontiers of Romance - including the revitalization of its bookstore neighbor and rival, fantasy, along with a host of spinoff subgenres. None of it is realistic, but much of it thrives on the artful faking of realism.
The launch images of the SM-64 Navajo come from an aerospace history blog. Compare to the ramjet shuttle at the lower right of the RM logo image above.