That's overly specific. How about "can, in principle, be at least as effective as a photon drive". I don't think one can really rule out one that's a bit more effective, even if I've no idea how one would make such a thing. (I believe that a photon drive has theoretic limits on it's efficiency that are a bit more stringent than the more general limits...but there might be some way of generating light that got around those limits...so perhaps "can't be any more efficient that a totally ideally optimal photon drive".)

Even so, I'm not sure. If it's something that can't ever return, most of the arguments about the maximum efficiency fail because there's no way of performing the measurements.

Also there are these cute arguments about drives that essentially require the mass of Jupiter (or more) to distort space-time. Some of those seem to be valid arguments for a drive without a reaction mass. They are just essentially impossible to build.

That said, perhaps these extreme devices...things involving zero point energy, FTL drives, reactionless drives, etc. are really just pointing out a place where the theories are wrong. None of these devices are actually buildable, so nobody can test them, as they all require some form or other of unobtainium. (Constructs with negative mass, portable masses heavier than Jupiter, etc.) I still remember "Rotating cylinders and a global causality violation", even though the plot of the story was a bit ... acausal. (The story doesn't seem to have any on-line references, but *it* was a reference to https://www.franktipler.com/ti... )

More to the point, if they don't collect personally identifiable information, how do they know that you've paid.

Well, this summary is based on a story from someone quoting a story in The Guardian. Not the best way to get accurate news on science.

That's an extreme formulation. It does imply that certain efficiencies would be equivalent to perpetual motion, but if the amount of energy required were sufficient to offset the gain in relativistic mass & potential energy I don't believe the argument fails. And it might be able to use half that energy, as the contradiction doesn't occur until it returns to the origin. And there's no thermodynamic reason that staying stable in a gravitational field should require any energy. (Anything in orbit is an example of that.)

I don't believe that this device will work, but I believe that your argument doesn't work either.

It's not a term for which there is a "generally accepted" definition. It's slang, which is widely variable between sub-populations.

The general idea of "drone" is usually someone who's useless.
The general idea of "suit" is someone who dresses excessively formally.
These are both judgements based on the perceptions of the one doing the describing.

If you think of it as a missile, you've also got a different idea than what I'm talking about. It's sort of a cross between a missile and a fighter that is designed to work in swarms, run by a "home base" that could be a large truck for small swarms of short distance versions. Imagine *highly* souped up model airplanes that are designed to act like missiles, if called upon. Long distance versions would probably always be more ammunition than craft (sort of like cruise missiles) for cost reasons, but shorter range versions would be expected to be refuel-able, and reusable unless the particular craft was used for an attack.
FWIW, I expect most of them to be relatively short-range, but too fast for the quad-copter design to work. Perhaps one model could be designed for "site defense".

I don't expect swarms to use the same form factor as a fighter. Really I expect them to be a cross between a fighter and a missile. No guns on board, and no missiles on board. Yes, fly like a plane, and land safely back home if you can, but also the attack mode is to crash into the target (or get close enough, and explode). Size will (and design details) will be dependent on desired range and speed.

As a result, each individual craft will be a LOT cheaper than current fighters. But a swarm may well be even more expensive. (Depending on swarm size and desired range and speed.)

The story lines were derivative. But no more so than the current ones. The story lines have been slowly evolving since the Greek plays. (We even still use some of the Greek terms to refer to them.)

Movies have become more derivative every decade since the motion picture camera was invented. This is the "low hanging fruit" observation.

People only have a certain number of desires, and only desire a certain amount of change. As it gets more difficult to come up with something new that people like, something old will get repeated more. As there gets to be a longer history of "something old that people liked", something new will be created less often.

It's not just movies. You can see it everywhere. Consider, e.g., software. A new edition has to change something noticeable, but it gets harder to come up with something new that people will like as much.

The time when we could (sometimes) rely on legislators to mandate basic security was back when they understood how basic security worked. In these areas only (some) tech specialists do.

That is, indeed, the most ethical. It's the way I chose. But I never deluded myself into believing that it would alter the behavior of the companies. Only two things (that I've thought of) stand a chance of doing that.
1) If you stop selling something that you are the monopolizer of sales in, you lose all associated copyrights. (And possibly all associated patents.) I.e. legal action to make things that you buy act is if they are yours.
2) Massive community on-line attacks whenever a company disables something that it's sold.

I don't think either of those have much chance of happening, and the second would be quite dangerous.

There's probably no "the" filter. It's probably a raft of multiple pieces. Some species won't be able to survive away from their home planet. Some will be aquatic (or other heavy medium). Some won't be able to tolerate the communications lag time. Some will kill each other off in suicidal war. Etc. Etc. Etc.

And another part of the filter is, since FTL appears to be impossible, (if only because of collision with grains of dust) once you've spent thousands of years in space, that's what you're adapted to, and then you don't want to (or can't) visit a planet.

I never agreed to allow my printer to connect to the internet. Even though I always used HP ink (I don't print that much), my printer still shut down, because I wouldn't allow it connection to the internet.

HP has become garbage.

There were contributions from multiple countries. You can point to particular problems that the Russians solved, but also some the the folks in the US solved. And the Germans. (And, IIRC, the French.) If you go back far enough, most of the progress happened in China.

For that matter, I suspect that in the 1700's much of the progress happened in Britain. (Consider "in the rocket's red glare", and there was a lot of work on rockets between ships...often for carrying a line to allow a rescue.)

China is NOT communist. They pretend to be, but they are actually a tyrannical oligarchy. (OTOH, no large government can ever be communist, as the theory doesn't scale beyond around Dunbar's number of people...and that requires a charismatic leader.)