Over a long enough timescale, though… really, really slow solar trickle charge to a space-capacitor bank? A thousand years’ suns, culminating in a glorious orgy of smelting?
But I still think it's impossible on an asteroid. No nitrogen, very little sunlight, wrong temperature, zero pressure, etc. They are already at their limit on Earth.
When we see currently insurmountable problems in creating a piece of technology, it's absolutely possible that we'll never be able to build it. Even if it is theoretically constructible, there is no reason to believe that the way to build it would be found before, say, the sun runs out of hydrogen.
There's absolutely no evidence of that on the article.
If you treat evidence as in the law of excluded middle, then yes. But if you are ready for a probabilistic evidence, then the article is a piece of evidence.
It chains Fermi Paradox, and our lack of knowledge how to do metallurgy in space. They both combined raise probability of impossibility of Von Neumann probes. It is not a proof that rules out Von Neumann probes, but it raises doubts about them.
The thesis was, “I would like to suggest that the hardest part is the one that gets a single sentence: ‘mines local material and builds a copy.’” And so naturally the points in the article are only trying to support that point.
The closest we get to what this thread is talking about is the concluding remark on the Fermi paradox. Which doesn’t rest on the idea that it’s a practical impossibility; just on the suggestion that it may be hard enough that we can’t just assume civilizations that are in principle capable of building them are likely to actually do it.
A lot of computational power can be thrown at the problem in this time. So, the problem should admits no shortcuts, no decomposition into simpler problems, no alternative ways to get similar functionality that allow shotrcuts or decomposition. The result should look like a jumble of atoms that somehow produces the required functionality.
I wonder which problems can admit only this kind of a solution.