You vastly over-estimate what's possible for any of us to know for certain about developments and discoveries that are centuries in the future. I wondered what you were going on about concerning "laws of physics".
I'm not talking about the future. The idea I was addressing was the assumption that it was possible for aliens to have powers that can't exist on Earth just because they're alien. My point is that the laws of nature are universal. Aliens are not magic, and they would be bound by the exact same restrictions on physics, chemistry, evolution, and common sense that apply here on Earth. If it were possible for effectively magical psychic powers to evolve anywhere in the universe, then it would equally possible for them to evolve on Earth, in which case they probably would have already.
This is a common idea in science: the principle of mediocrity. It's the principle that Earth is not exceptional or unique in the universe, that the rules that apply to us apply everywhere else. Just about every time we've believed that Earth or humanity was somehow special or exceptional or central to the universe, that belief has turned out to be wrong. So it stands to reason that the reverse is also true: That Earth does not
lack anything that's common elsewhere in the universe. Sci-fi has lots of alien superpowers and exotic materials (like dilithium) that aren't found on Earth, but that isn't very plausible, because Earth and the Sun formed from the same interstellar gas and dust that formed the other stars of the galaxy.
Again, you only allow for two categories, fantasy and hard SF.
Whatever gave you that idea? Of course it's a continuum. But as I've been saying, there is a difference between something that's an implausible extrapolation of a real scientific principle, like warp drive or transporters, and something that's based on a purely magical or superstitious idea, like mind-reading or levitation. I'm not saying the former is perfectly plausible; I'm just saying they're two distinct categories and grades of implausibility. Warp drive may never actually exist, but at least we have a solid physical and mathematical understanding of how it would work if it could exist, what principles and laws it would be based on. It's an unlikely but mathematically permissible solution of the equations of General Relativity that we know for a fact to be true. But psi powers are just handwaves, plot contrivances that effectively work by magic. Many writers use the invocation of "telepathy" or "psi" as an excuse to ignore physical laws and offer no explanation for how that can happen, as if just saying the word were all the explanation necessary. There is a functional difference there. It may not be a difference that matters to every reader, but it is a difference.
I don't particularly like hard SF. I dropped my Analog subscription recently. Hard SF is too rooted in what we know NOW, not daring to venture far beyond that.
I don't agree. Yes, near-future hard SF has been popular in the past couple of decades, so I can see how you'd get that impression, but that's not the only kind there is. The power of science is that it lets you extrapolate beyond what you already know. The whole purpose of a scientific theory is to allow you to make predictions beyond existing observations, to ask "What if?" questions about things you haven't done or seen and be able to determine what a likely answer would be (or at least a testable answer). There is a lot of hard SF that makes very bold extrapolations into the distant future, like the work of Greg Egan or Steven Baxter, and it's that grounding in theory, that ability to follow a framework of reasoning that leads from a known fact to its ramifications and its interactions with other knowns, that enables us to think of possibilities that never would've occurred to us otherwise.
People sometimes approach Trek from a different direction than someone who's interested in SF in general. They see the word "science" in "science fiction" and see it as a sort of promise of scientific fact, according to what we know today. It's not science. It starts with some scientific fact, and extrapolates, sometimes wildly.
Again: Science
is extrapolation. Just listing what we already know is not science; it's just bookkeeping. Science is about theory, and a theory is a
predictive model. "Fact" is not a word that scientists even use, partly because it implies an absolute certainty that's anathema to science, and partly because a "fact" is merely an observation, a data point, and is effectively meaningless until you can place it in a larger context. Existing observations are just the starting point, the data used to construct a theoretical model that allows you to make testable predictions, which will in turn lead you to new data that will allow you to formulate further models that will allow you to make further tests, and so on and so on and so on. Extrapolation beyond the known is exactly what science is for.
And that's why extrapolative fiction is called science fiction. The scientific method is about asking questions and making predictions. Given what we already know, what would be likely to happen under such-and-such conditions, and what would that tell us? How would gravity behave if an object's density rose toward infinity? How would the weather change if the atmosphere's average temperature rose 5 degrees? And that's the basis of science fiction as well. It's been said countless times that SF is driven by the question "What if?" A science fiction story is the literary equivalent of a scientific hypothesis -- a model that predicts a possible result of a conjectural situation. How would human lifestyles, cities, and notions of privacy change if we had mass teleportation? How would two starfaring species deal with the security concerns raised by first contact? An SF story is a literary thought experiment.
Star Trek, and pre-revival Dr Who, were always soft SF.
But not to the same extent.
Star Trek was actually pretty exceptional -- it was one of the vanishingly few SFTV series whose producers ever even
bothered to consult with scientists and researchers. Roddenberry always wanted ST to be believable and grounded, and while he did take a lot of artistic license, he at least made an attempt to get the science at least somewhat right, which was virtually unprecedented. Before ST, where American SFTV was concerned, only the '50s shows
Tom Corbett, Space Cadet and
Men Into Space had ever bothered with any kind of science consultants or technical grounding, and virtually nothing after ST made any attempt at credibility until ST returned. Look at
Battlestar Galactica from 1978, for example. One episode had them passing out of one "galaxy" and immediately entering another, as if they'd just crossed a state line. The season finale said they'd passed through several galaxies in the course of roughly a year's travel, even though it had previously been established that "lightspeed" was their
fastest possible speed. And let's not even get started on
Space: 1999 and its errant Moon that was blown out of Earth's orbit and somehow drifted through interstellar space at FTL speeds. Yes, ST had its fanciful elements, but it was far closer to the "hard" end of the SF spectrum than anything else we had in US television for a long, long time.
As for
Doctor Who, it dabbled with credible science for a couple of seasons, when it brought Kit Pedler aboard as a scientific consultant. (In fact, today is the 50th anniversary of the debut of Pedler's creations, the Cybermen.) But aside from that, it was always on the fanciful end of the sci-fi spectrum, much more so than
Star Trek was.
It's only with the 2005 revival of DW that they started violating the confines of soft SF with impunity, making the series ACTUALLY magical.
No, both
Doctor Who and
The Sarah Jane Adventures stuck to the old rule -- going back to "The Daemons" -- that "magic" is just advanced alien science or telepathic powers that we don't understand. It was only
Torchwood that treated it as overtly supernatural. But of course that's an academic distinction, because the phenomena were equally fanciful regardless of the explanation.
"That's a spurious question, because the issue of whether alien life exists elsewhere in the universe is entirely separate from the question of whether it's visiting us"--- Yes. It is. That was my point, how one doesn't follow from the other.
And that doesn't work as an analogy for physics-defying psi powers, because the laws of physics are universal, and if something is physically impossible on Earth, it will be physically impossible everywhere. It doesn't matter what planet you're from, you won't be able to levitate a truck without needing to expend exactly as much metabolic energy as you'd need to lift the truck with your muscles, and without being subject to the laws of action and reaction or the need to achieve proper leverage somehow.
