Oh wow the concept of Vitamins, which I learned about from the Reprap Project, must have come from that 1980 NASA study!
A metallurgist's doubts about self-replicating probes
71–80 of 103 posts
Re: A metallurgist's doubts about self-replicating probes
#72This article contains 19 em-dashes, as well as the following direct quotes:
Not X, but dramatic Y:
- "But the missing few percent are not marginal; they are precisely the hardest items"
- "is not an engineering detail. It may be the entire problem.
- "the galaxy may be quiet not because nobody tried, but because replication is harder than arithmetic suggests."
as well as at least two other longer "not X, it's Y" type phrases.
Also, melodramatic phrasing like "Replication must outrun degradation — and degradation never sleeps."
Yes, someone could have written these manually, but these particular patterns are the things I notice most commonly in LLM outputs that I don't see in known-human writing.
Re: A metallurgist's doubts about self-replicating probes
#73Wouldn't a counter this argument be biological systems? These are reasonable points as long as we are talking about current methods, but I assume if we were to get to the point of self replicating probes it would be done by something like nanotechnology, synthetic biology like systems.
Why would biological systems be a counterargument? Smelting metals and sustaining life both require an enormous amount of water and about ~1ATM of atmosphere, as far as we know, and there's no plausible known mechanism for sidestepping this requirement. So "magical synthetic biology that can self-replicate in space" is actually a worse solution to the problem than "magical metallurgy that can be done in space" since…
You're making assumptions that the parent isn't necessarily making. Imagine sending humans to other earthlike planets on hypothetical generation ships. Those humans could throw away their technology and rebuild from zero over thousands of years to send more spaceships of humans to yet further planets. Presto, an example of self-replicating biological von Neumann systems.
Re: A metallurgist's doubts about self-replicating probes
#74This article contains 19 em-dashes, as well as the following direct quotes: Not X, but dramatic Y: - "But the missing few percent are not marginal; they are precisely the hardest items" - "is not an engineering detail. It may be the entire problem. - "the galaxy may be quiet not because nobody tried, but because replication is harder than arithmetic suggests." as well as at least two other longer "not X, it's Y" type…
Thanks. You saved me some time.
Re: A metallurgist's doubts about self-replicating probes
#75Earlier quoted context omitted.
So that adds some extra "benefits" (mutation and natural selection improves the probes over time) along with some extra difficulties - how do you keep the self-reproducing probes "on-task" from one generation to the next? How do you instill "explore and report home" as an innate goal to a mutating system?
I would argue that, over the time scales at which Von Neumann probes would hypothetically spread, “report home” may be a useless or even wasteful requirement. Even if somebody were still around to hear the message, what is the likelihood that they would still be listening? Or be able to interpret it?
If we build self-replicating machines and send them out into the universe we're really just sending out our evolutionary progeny. Hopefully they would remember us fondly.
Re: A metallurgist's doubts about self-replicating probes
#76> Shrinking that into a 500 kg seed — or even Freitas’ original 100-ton seed — is not an engineering detail. It may be the entire problem. How many AI tells can you count there? But honestly (see what I did there?) the AI slop is reasonably cleaned up in this piece. However, the essence of the argument has two deep flaws. One is that the time to complete an interstellar voyage is extremely long and you need some exer…
300 years ago people also believed alchemy was a serious field of study
And today we call it transmutation - https://en.wikipedia.org/wiki/Nuclear_transmutation
Re: A metallurgist's doubts about self-replicating probes
#77> Shrinking that into a 500 kg seed — or even Freitas’ original 100-ton seed — is not an engineering detail. It may be the entire problem. How many AI tells can you count there? But honestly (see what I did there?) the AI slop is reasonably cleaned up in this piece. However, the essence of the argument has two deep flaws. One is that the time to complete an interstellar voyage is extremely long and you need some exer…
The subheadings are all full of AI tells. > The closure problem, honestly accounted > A thermodynamic framing All of those read like AI, especially considering that the subsections aren't consistent. Some are numbers, some are not, some are framings some are problem juxtapositions. EM dashes everywhere, AI tells in subheadings, "It's not X it's Y" all over the text of the body. This is clearly AI writen. Notice also…
> Notice also the article has two by lines. At the top it's "by Paul Gilster" at the top of the text it's "by Peter Marinko".
It is Paul Gilster's blog. It looks like all articles there are by him, hence his byline at the top.
In this particular article he writes an introduction talking about self-replication, then says "Right now I want to introduce Peter Marinko, who today weighs in on self-replication and the problems therein", describes Marinko, and then the rest of the text is Marinko's, hence the second byline after Gilster's introduction.
Something similar happens in the next article on the site. Marinko write a length response to comments on the first article. Gilster decided that would be better as a separate article to further discussion: "When Peter wrote recently with his thoughts on reader reactions, I asked him for permission to run it as a regular post rather than a comment, because I think this is a lively question and would like to see us continue to explore it".
So that too is a post by Gilster, and so with his byline, but after an introduction it just run's Marinko's text, so has a second byline for that section.
He does the same thing on this article [1]. He wrote a review a paper, some commenter had interesting thoughts, and Gilster posted an article talking about that, introducing the commenter, and then the rest of the article was the commenter's text. So two bylines, one for the intro and one for the guest text.
It looks like the other articles on the site are just Gilster, and so only have one byline.
[1] https://www.centauri-dreams.org/2026/06/05/observations-on-t...
Re: A metallurgist's doubts about self-replicating probes
#78Wouldn't a counter this argument be biological systems? These are reasonable points as long as we are talking about current methods, but I assume if we were to get to the point of self replicating probes it would be done by something like nanotechnology, synthetic biology like systems.
Biology ignored some of the most abundant elements because they can't be worked with under the constrained temperature and pressure conditions where biological systems operate. Biology barely uses any silicon, even though it is the second-most common element in the biosphere. Biology does not use aluminum, the third-most common element, at all. Biology does use iron but cannot reduce it to the pure metal. In fact, bi…
> In fact, biological systems produce no metals
I'm going to be very pedantic and point out a counterexample: https://en.wikipedia.org/wiki/Scaly-foot_gastropod
Re: A metallurgist's doubts about self-replicating probes
#79Earlier quoted context omitted.
Life as we know it until now has big difficulties outside goldilocks zone. It would theoretically be possible to make microbes (or fish?) that float high in Venus atmosphere, if we put money into 200 years of research, but no way life as we know it could ever break up and "eat" an asteroid.
Never say never https://en.wikipedia.org/wiki/Endolith
Very interesting. I didn't know about them.
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.
Re: A metallurgist's doubts about self-replicating probes
#80Earlier quoted context omitted.
The self-replication assumes also that there is enough energy stored in each planet (or coming from a Sun) to do the work... That is pretty much unlikely.
Any chemical bond is a potential source of energy. Plenty of sources of potential energy too able to be converted to work.
That's the source, but for chemical reactions you also need a sink. For instance gasoline is not usable as an energy source without an oxidant. Take away the oxygen in Earth's atmosphere (an asteroid has no atmosphere at all) and now gasoline has no potential energy available. Asteroids have no available oxidants (regolith was already fully oxidized long ago).